Armstrong World Industries EHU-700 Series Humidifier User Manual
Contents
1. 16 25 30 31 500 b Ni Figure 28 2 EHU 700 Steam Generator Repair Parts List 28 MAINTENANCE RECOMMENDED MAINTENANCE SCHEDULE 1 TO 2 DAYS AFTER START UP 1 Check unit operation 2 Look in drain pan for leaks 3 Check steam piping for leaks 4 Observe duct low points for signs of poor humidity distribution 5 Be sure unit is draining freely by pushing the manual drain button the manual tank off button should not be depressed 1 MONTH TO 1 YEAR 1 Repeat the 5 steps outlined above 2 Clean repair or replace steam generator STEAM GENERATOR MAINTENANCE General The steam generator is basically the only part of the EHU that requires regular maintenance This maintenance may include cleaning or replacing the tank itself or the electrodes We recommend sub stituting a spare generator in order to minimize downtime and labor requirements The replaced gener ator may then be serviced when it is convenient Tank Cleaning As the water in the steam generator boils away the minerals in that water come out of suspension and are deposited on the walls of the tank and on the electrodes This process leaves the tank walls coat ed with a white or2. 24 CM24 10 30 14 63 17 77 19 86 25 11 3 29 13 2 42 19 32 CM32 8 40 19186 22 10 26 11 8 33 15 38 17 2 40 CM40 8 50 24 10 9 28 127 32 14 5 42 19 difier One Large Steam Generate 20 CM20 10 25 12 54 14 63 16 7 3 21 9 5 24 10 9 35 15 9 38 17 2 42 19 48 21 8 60 1272 24 CM24 10 30 14 63 17 77 19 86 25 113 29 13 2 42 19 46 20 9 50 22 7 58 26 3 72 327 32 8 40 19 86 22 10 26 11 8 33 15 38 17 2 55 249 61 27 7 66 29 9 77 34 9 96 43 5 40 8 50 24 10 9 28 127 32 145 42 19 48 21 8 69 31 3 76 34 5 83 37 6 96 43 5 120 54 4 48 6 60 29 13 2 33 15 39 17 7 50 22 7 58 26 3 83 37 6 91 41 3 100 45 4 115 522 Two Steam Generate 40 1 8 50 24 10 9 28 127 32 14 5 42 19 48 21 8 69 31 3 76 34 5 83 37 6 96 43 5 120 544 48 24 6 60 29 13 2 33 15 39 177 50 22 7 58 26 3 83 37 6 91 41 3 100 45 4 115 52 2 144 65 3 64 cm32 4 80 39 177 45 204 51 123 1 67 30 4 77 34 9 111 50 3 122 55 3 133 60 3 154 69 8 192 87 1 80 CM40 3 100 48 21 8 56 25 4 64 29 83 37 6 96 43 5 138 62 6 152
3. TABLE OF CONTENTS SECTION 1 WARNINGS PRE INSTALLATION Check shipment Check local codes Site selection INSTALLATION Electrical wiring Water supply Drain connection Steam dispersion tube Control wiring High limit humidistat Airflow switch Audible alarm Wiring PREPARATION AND INSTALLATION SECTION 2 START UP AND OPERATION DISPLAY INSTRUMENT PANEL START UP PROCEDURE in p Feri En a SECTION 3 TROUBLESHOOTING AND MAINTENANCE TROUBLESHOOTING GUIDE Principle of operation Operational guidelines IB WATER QUALITY AND Conductivity too low Conductivity too high MAINTENANCE Recommended eene Steam generator maintenance re Tank removal and Chemical tank c
4. ducts with a depth of 8 inches less Hole in Dut Avoid placing manifold in downward high For Steam Capacity velocity air flow as dynamic air pressure will restrict steam flow 01 75 150 Use the template provided to cut installation holes in the duct for the dispersion tube Figure 8 1 EHU 701 Figure 8 2 EHU 703 704 ae _ 1 1 2 Copper Tube as in Figure 7 2 and optional drain tube pP Lem as a Female i Pipo Adapter M 1 2 Insert the dispersion tube into the duct so the holes face upward Fasten the mounting plate to the outside of the duct with sheet metal screws If the dispersion tube is 36 long or more support the far end with threaded rod or similar means J EHU 701 I4 Steam Generator Toj L e Connect the dispersion tube to the steam generator using 174 EHU 701 174 EHU 703 704 nom size hard copper tube customer supplied and the two short hoses supplied with the humidifier Figure 8 1 Pipe size may need to be increased to 172 or 2 when piping runs are long or back 3 V Y pressure in duct is high see Figure 9 2 Steam D ube 4 If piping plus duct back pressure exceeds 4 WC please consult factory In addition a short length of nominal 1 threaded black iron pipe and copper tube to female pip
5. Remember this high limit function is not a safety device For critical situations provide installation with normal protections required to ensure a safe operation gt 5 i 5 3 Supply Humidity HUMIDITY SET POINT RESET BY OUTSIDE TEMPERATURE The A17898 H270 humidistat has an optional Figure 38 1 outdoor temperature sensor This sensor is used to reset the humidity set point during the cold season to minimize condensation on windows and building structures When the outdoor temperature falls below the selected high temperature parameter HT 32 F in the example Figure 41 2 the humidity set point will User Setpoint start to decrease The lowest humidity set point will be reached at selected low temperature parameter LT 20 F 20 25 30 35 40 45 Outside Air Temperature RH The set point decrease from original set point down to the lowest set point determined by the parameter rE In the example Figure 41 2 rE was set to 20 therefore the humidity set point dropped from 45 to 20 If you don t use the outdoor reset feature put a jumper between terminals 6 and 9 supplied with the humidistat 38 APPLICATION EXAMPLE Steam humidification system controlled by a 0 to 10 Vdc valve wired to output 1 Remote humidity display using 0 to 5 Vdc signal is wired to output 2 The humidity sensor is located in the return air duct A proportional high
6. 4 Split the tank referring to the directions on page 33 of this manual and examine the inside of the tank and the electrodes a If the tank is black or dark brown the electrodes may have disintegrated and chemical cleaning may not be effective The tank can be cleaned with the following process but the electrodes may need to be replaced b If tank and electrodes have a white tan grey mineral accumulations and or the tank is partially filled with loose lime accumulations proceed with chemical cleaning 5 Empty any loose deposits from the bottom tank half Both tank halves and the barrier assembly if present can be cleaned using a scraper a stiff bristle brush and water spray as required Refer to the directions on page 33 of this manual for details on removing the drain screen for further cleaning if necessary 6 Remove the electrodes from the upper tank half following the directions on page 33 of this manual Loose and or soft deposits should be scraped from the exterior of the electrodes before chemical cleaning 7 Prepare the chemical cleaning solution as per manufacturer s recommendations and fill a plastic bucket to a sufficient level to soak the electrodes Be certain not to submerge the electrodes beyond the level of the screen 8 Let the cleaning action take place for 15 minutes Remove the electrodes from the bucket and rinse them thoroughly with a clean water spray 9 Observe the electrodes to determine if another
7. the bottom of the steam generator tank and rises until it Fan Interlock High Water reaches the electrodes Upon contact electrical current flows Controller p through the water causing it to boil and produce steam SS Figure 17 1 Line As the water level rises Figure 17 2 increased electrical Figure 17 2 current flows through the water producing more steam This increase will continue until the desired current level i e External Power required steam output is reached At this point the fill valves as oe will cycle off and on to maintain the desired amperage 5 Current Sensor The desired current level is a function of the nominal current rating humidistat demand and the automatic capacity adjust ment feature Controlling Humidistat When the humidistat senses the added moisture the air Men the demand for humidity begins to drop As the demand T drops the output of the unit is modulated down by boiling uy Float Switch away water and not filling This allows the amperage to Drain Valve decrease thereby reducing the steam flow The fill valve can Eid then cycle at the lower steam output current requirement When the humidistat demand signal drops below a minimum Figure 17 3 25 demand the contactor is de energized and steam out mes put stops Figure 17 3 4 Steam output also be stopped by a duct high limit Current Sensor ___ humidistat or a
8. the demand mode light will be on the display will show the control stat demand and the unit will return to normal operation The complete I O diagnostic check lasts less than 2 minutes 22 WATER QUALITY AND TREATMENT FOR SERIES HUMIDIFIERS GENERAL Series EHU 700 electronic humidifiers use ordinary tap water in their operation The quality of this water affects both the operation and the maintenance of the humidifier How the EHU works The EHU is an electrode boiler When no water is present the electrodes are separated by air an insulator so no current flows When tap water contacts the electrodes it conducts current between the electrodes heating the water How much current passes between the electrodes is dependent on the conductivity of the water which is measured in micromhos cm uMhos cm EHUs can operate effectively with water conductivity in the range of 50 low to 800 high uMhos For conductivity greater than 800 uMhos please consult facto ry The optimum incoming water conductivity level is 200 400 uMhos cm the greater the conductivity of the water the lower its level will be in the tank in order to draw a given current In general the EHU 700 Series will adjust its drain cycle to maintain the water level around 1 3 1 2 full in the tank What affects conductivity The minerals mainly calcium dissolved in the water Pure water is NOT conductive and can t be used exclusively in an EHU without special proce
9. Humidistat Duct mounted control humidistats are also available for installation where sensing and control of return air or exhaust air ducts is preferable Figure 10 1 Please refer to manufacturer s recommendations for further information on the location mounting and operation of the various control humidistats 10 HIGH LIMIT DUCT HUMIDISTAT Remove the jumpers tab from terminals 10 amp 14 and wire the high limit stat between these terminals Refer to Figure 10 1 and Figure 11 1 the overall wiring diagram for more information A duct mounted high limit humidistat is recommended to prevent over saturation of the duct air Use an on off controller that opens on fault high humidity Humidistat should be set for a maximum of 90 RH Alternately a modulation high limit humidistat may be used on applications such as variable air volume VAV Locate the high limit humidistat approximately 10 3m downstream of the dispersion manifold If 10 3m is not available consult the factory 11 AIRFLOW SWITCH An airflow switch is recommended to deactivate the humidifier when there is insufficient air flow in a duct system A duct pressure switch is preferred as an airflow sensor The pressure switch should open on insufficient airflow opens on fault Airflow switch should be mounted in supply air duct upstream of humidifier dispersion Remove the jumper tabs between terminals 9 amp 15 and wire the airflow sensor between these terminals See Figur
10. at 20 mA max for both outputs Power 24 VAC 15 10 50 60 Hz 2 VA Base and casing Off white self extinguishing ABS plastic Triac outputs can only switch AC loads Use relays when switching dc loads Note 1 Humidity sensor Solid state humidity sensor Suitable for normal clean air Not to be used in corrosive or harmful environment 36 DIMENSIONS Figure 37 1 Dimension drawing Duct Humidistat Invisible 1 1 4 32 mm Note Specifications and equipment are subject to change without prior notice TABLE 5 SENSOR CHARACTERISTICS Voltage between black and white wire terminals 6 and 7 HUMIDITY SENSOR OUTPUT 0 1 05 V 5 1 19 V 1096 1 34 V 1596 1 48 V 20 1 63 V 25 1 77V 30 1 92 V 35 2 06 V 40 2 20 V 45 2 35 V 50 2 49 V 55 2 64 V 60 2 78 V 65 2 93 V 70 3 07 75 3 21 V 80 3 36 V 85 3 50 V 90 3 65 V 95 3 79 V 100 3 94 V 37 AIR SUPPLY HIGH LIMIT HUMIDITY SENSOR The A 17898 H270 includes a high limit circuit This allows Table 4 Example showing proportional high the use of a second humidity in the supply air Input signal limit override signal in supply duct goes to terminals 8 on the humidistat High limit set point is preprogrammed at 85 It can be readjusted using the A19517 service tool If you don t use the high limit feature connect a 1 watt resistor between terminals 8 and 10 supplied with the humidistat
11. even though the stat demand remains at 100 Consistent drain cycles of two seconds or less 23 Results Excessive time needed to reach set point during star up Poor humidity control Remedy Add 1 2 teaspoon of Epsom salts to the fill cup After start up the automatic drain program should maintain the unit at full capacity If problem persists contact the factory WHEN WATER CONDUCTIVITY IS TOO HIGH Indicators Water level just touching tip of electrodes Arcing and foaming in the tank Frequent drain cycles every time the fill valve opens that last up to 10 seconds Results Tank frequently needs cleaning Poor control because of excessively low water level Electrode destruction Remedies If you have pure water available such as de ionized water Reverse Osmosis diffusion water or distilled water they can be blended with tap water to reduce the total mineral content Pure water alone is not conductive enough to pull current The water is too pure when the Tank Full light comes on excessively Consult a water purification equipment vendor for the proper blending equipment or the Armstrong factory for more information regarding use of purified water The blended water conductivity should be in the 200 400 uMhos cm range Softened water is not recommended for use with the Series EHU 700 Humidifiers Water softeners replace the calcium ions in the water with sodium ions As softened water boils the sodium i
12. f 0 135 ohms 1 2 5VDC ON OFF 0 135 OHM 24 0 10VDC 12VAC 1 9 3 9V0C g on off To adapt the EHU 700 to these different types of control humidistats jumper BJ4 and BJ5 on the print ed circuit board Figure 9 1 must be manually changed and the humidistat must be wired to the appropriate connections of terminals 1 2 amp 17 Refer to Figure 9 1 or the sticker on the inside of the cabinet for proper jumper locations Figure 9 2 Chart 9 1 Feet of equivalent copper pipe for copper Pressure Loss in Copper Pipe pipe fittings 40 Equivalent Run 90 Long Elbow Tee 10 20 30 70 50 60 70 80 90 100 110 120 Hr Steam 10 1 OUTPUT 1 0 to 10 Vde MAIN SENSOR Humidifier INPUT Modulating High Limit Sensor Safety High Limit Humidistat optional 6 10 Ft Air Flow Switch Outdoor Temperature Sensor Connections HIGH LIMIT SENSOR ouside Air Humidifier Location 1 EXHAUST AIR OUTDOOR TEMPERATURE 10 Vdc Main Humidity Sensor Wall Mounted Control Humidistat Wall mounted humidistats are usually installed 4 ft to 5 ft above floor level Oft
13. greater than 35 2 The fan interlock circuit is closed 3 The high limit humidistat circuit is closed There is a time delay of fifteen seconds in the contactor operating circuitry to prevent it from cycling too rapidly after it has been turned off Monitoring Stat Demand Indicates the demand for humidity in relationship to the control range of the humidistat 0 indicates that the humidity requirement has been exceeded 100 indicates that the humidistat is calling for full humidifier output In general a reading of around 50 indicates that the set point has been met 18 Monitoring Current While the unit is filling the current should increase As the current approaches the maximum rating of the unit it increases more slowly especially in higher capacity units With the tank on and the fill and drain circuits idle the current should fall slowly When the unit is draining the current should decrease at a moderate rate Monitoring Power The percentage power equates to the percentage of maximum steam output The percentage power reading will increase and decrease proportionally to the current draw Overcurrent protection circuitry starts initiating drain cycles as the power reading approaches 110 The overcurrent failure routine is initiated at about 120 Automatic Drain Operation The microcontroller will energize the drain valve at the beginning of the fill cycle to reduce the conduc tivity and mineral build up in t
14. is reached the HIGH WATER light comes on and the fill valve is blocked until some water is boiled away and the water level drops This is not uncommon on startup The diagnostic display mode will indicate CO1 NOTE the high water light goes off as soon as the high water condition is cleared but the operation the fill valve does not resume until after a fifteen second delay period If C01 is displayed and the water level is in the lower half of the steam generator high static pressure exists contact the factory for assistance TANK NEEDS CLEANING If the HIGH WATER lights is on continuously during normal service i e after initial startup and the current is not increasing the tank probably needs cleaning refer to the maintenance section of this manual If this condition persists without being serviced the display panel will display diagnostic message C02 The unit will shutdown and the dry contact will close to activate the remote alarm NOTE False 02 messages may if incoming water is very pure lt 100 uMhos cm Please consult factory INTERLOCK CIRCUIT The fan interlock circuit may be a sail switch or preferably a duct pressure switch When air flow in the duct is not present the interlock circuit should open and the microcontroller will de energize the contactor The diagnostic mode will display the message and the fill solenoid is blocked 20 04 05 06 07 08 HIGH LIMIT CI
15. should be installed in accordance with ALL applicable building plumbing and electrical codes 24 Min Steam Generator 5 Min Drain SITE SELECTION Tank Removal Connection Access Electronic steam humidifiers must be installed in locations that allow routine inspection and accessibility for maintenance operations See Figures 4 1 amp 4 2 for access space Figure 4 2 EHU 703 704 24 Side Clearance 4 Sid Do not place electronic steam humidifers Cjearance T in locations where unusual instances of malfunction of the humidifier or the system might cause damage to non repairable or un replaceable 24 Front or priceless property Clearance 5 Min Drain Connection Access 1 The mounting surface should be wall capable of supporting the maximum humidifier weight The maximum operating weight is Model unit Water Total 701 60 Ibs 20 lbs 80 165 703 83 Ibs 30 Ibs 113 Ibs 704 95 Ibs 60 Ibs 155 Ibs The location chosen should be inside with a minimum ambient temperature of 40 F and maximum of 100 F The humidifier should not be mounted on hot surfaces The location should be close enough to the air duct so that the length of steam pipe is as short as possible A length of 10 ft or less is ideal the maximum recommended length for running distribution piping is 4
16. show 06 to indicate this condition and the dry contact will close to activate the remote alarm Fill system failure can be due to excessive or insufficient inlet water pressure a failed fill valve solenoid a plugged fill valve failed open or a backflow preventer Refer to the maintenance section of this manual for resolution of these problems OVERCURRENT FAILURE The overcurrent limit OCL is 20 above the nominal amp rating of the unit When the actual current reaches the OCL the microcontroller will de energize the contactor and energize the drain valve for 15 seconds Then the contactor will be re energized to see if the drain valve has corrected the overcurrent condition This procedure is repeated 5 times If the overcurrent still exists an overcurrent failure indication of is displayed the unit is shut down and the dry contact will close to activate the remote alarm The unit will have to be manually reset and the overcurrent condition addressed by the maintenance personnel An overcurrent failure can result from the cold startup of a tank that was previously running at a high load resulting in the tank water becoming too conductive for start up If this is suspected manually drain the tank for 15 30 seconds then try to restart the system If the overcurrent failure repeats the drain system could be partially plugged or the tank may be in need of cleaning Refer to the maintenance section of this manual for resolutions
17. treatment is necessary 10 It is not necessary for the electrodes to be cleaned down to bare metal Removal of major accumulations is the only requirement 11 Helpful Hints Check the drain valve for proper operation amp good flow when the tank is drained prior to removal With the tank removed inspect the drain adaptor and hose from adaptor to drain valve to ensure that it is free from deposits which may interfere with proper drainage 31 12 Reassemble tank Make sure o rings still on electrode terminals Also check condition of steam generator o ring After a couple cleanings it will need to be replaced Make sure o ring is sealed in its groove and not pinched when halves are put together Do not over tighten nuts that hold electrodes place This is an o ring seal so nuts should be snug 13 Re install the steam generator tank Check out for proper operation 32 TANK DISASSEMBLY CLEANING AND ELECTRODE REPLACEMENT MODELS EHU 703 AND 704 SINGLE AND THREE PHASE Using a 7 16 wrench disconnect the jumper wires from the steam generator Remove 24 metal clips by pushing gently on top of each clip with a screwdriver while cupping the clip with the other hand Lift the top half of the tank free of the bottom half and rest it on the electrodes Use 4 wrench to loosen and remove the nuts from the six electrode studs Lift the top tank half from the electrodes Remove the o ring from the lower tank h
18. 0 feet of equivalent run The number of piping elbows in the installation should be minimized see Pages 7 and 8 for more information The unit should have ready access to electrical service a supply of ordinary tap water and a sewer into which the drain line can discharge hot waste water Figure 5 1 NOTE Please contact factory for duct applications offering high static pressure gt 4 WC Figure 5 1 T INSTALLATION 4 MOUNTING THE HUMIDIFIER MODEL EHU 701 Making sure the unit is level hold it against the mounting surface and mark the hole pattern Attach the units to studs or other sturdy structure with the two 3 8 x 172 lag screws provided MODELS EHU 703 amp 704 Making sure the mounting bracket is level attach it to studs or other sturdy structure with the two 3 8 x 172 lag screws provided Hang the humidifier on the mounting bracket 5 ELECTRICAL SERVICE WIRING Refer to the nameplate on the unit for recommended fuse size Table 6 1 relates the fuse size to the appropriate branch size A complete wiring diagram shown in Figure 12 1 is located inside the door of the humidifier IMPORTANT Please ob
19. 3 amp EHU 704 Drain connection use 1 ID Hose Supplied Drain rate 3 gpm Limited Warranty and Remedy Armstrong International Inc Armstrong warrants to the original user of those products supplied by it and used in the service and in the manner for which they are intended that such products shall be free from defects in material and workmanship for a period of one 1 year from the date of installation but not longer than 15 months from the date of ship ment from the factory unless a Special Warranty Period applies as listed below This warranty does not extend to any product that has been subject to misuse neglect or alter ation after shipment from the Armstrong factory Except as may be expressly provided in a written agreement between Armstrong and the user which is signed by both parties Armstrong DOES NOT MAKE ANY OTHER REPRESENTATIONS OR WARRANTIES EXPRESS OR IMPLIED INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTY OF MER CHANTABILITY OR ANY IMPLIED WARRANTY OF FITNESS FOR A PARTICULAR PURPOSE The sole and exclusive remedy with respect to the above limited warranty or with respect to any other claim relating to the products or to defects or any condition or use of the prod ucts supplied by Armstrong however caused and whether such claim is based upon warranty contract negligence strict liability or any other basis or theory is limited to Armstrong s repair or replacement of the part or product excluding any l
20. 68 9 166 75 3 192 87 1 240 108 8 96 CM48 2 125 58 26 3 67 30 4 77 34 9 100 45 4 115 52 2 166 75 3 182 82 5 199 90 2 230 104 3 NOTES 846 Volt units require 346 200 volt 4 wire system 2415 volt require 415 240 volt 4 wire system KW rating humidiity output Ibs hr x 0 345 for energy calculations only not for branch circuit sizing 6 6 WATER FILL SUPPLY Connect the unit to the building water supply 25 to 125 psig pressure Install a shut off valve near the humidifier Connect the water supply to the 3 8 tube compression fitting on the fill valve adaptor NOTE ORDINARY POTABLE TAP WATER IS RECOMMENDED IF POTABLE WATER IS NOT AVAILABLE CONSULT THE FACTORY SEE WATER QUALITY AND TREATMENT SECTION OF THIS MANUAL PAGE 23 FOR MORE INFORMATION DO NOT USE BRACKISH OR CONTAMI NATED WATER Figure 7 1 7 CONNECT DRAIN Connect to a suitable waste draining system Use the clear drain hose provided and a 1 copper pipe Figure 7 1 pitched La 1 per foot The drain water may be as hot as 160 F Drain it where it will not present a oar nese hazard to personnel An air gap to prevent LI ri Hose meide backflow is required if drain water is required to be less than 140 F use m tiltaget of Temp R Drain will be required as Chart 7 1 Selecting Proper Steam Dispersion Tube 8 INSTALL THE STEAM Steam Steam Di
21. After a couple of tank replacements the o ring should de replaced as well Connect power leads and on EHU 703 and 704 the loose end of the jumper wires to electrode studs using a 7 16 wrench three leads for 3 phase units two for single phase Refer to the wiring diagram in your unit for specific information 10 Connect the steam hose to the top of the steam generator with the hose clamp 11 Check all wiring connections at the main power contactor and control voltage terminal blocks Figure 14 1 as well as on the generator itself Energize the circuit breaker or main disconnect Refer to Start up Section if you encounter any problems when restarting the unit 30 STEAM GENERATOR CHEMICAL CLEANING PROCEDURE This procedure is intended as a guide only for the chemical cleaning of the generator in all EHU mod els Read and follow label directions on any cleaning product Check local codes before disposing of chemicals Caution Muriatic acid can cause severe chemical burns if not handled properly Wear rubber gloves and eye protection when using Read and follow carefully the safety procedures on the package 1 Obtain several gallons of muriatic acid Muriatic acid is the name for commercial hydrochloric acid It is available in most hardware pool chemical or farm supply outlets 2 Remove the tank following the Tank Removal directions in this manual 3 Let steam generator tank cool after removal from the EHU unit
22. Bulletin 527 G 7 Armstrong Installation and Maintenance Series EHU 700 Humidifiers Please Read And Save These Instructions The Armstrong Series EHU 700 humidifier is an electronically controlled non pressurized steam generating humidifier with its vapor discharged into a duct of an air handling system or through a fan package The Armstrong Series EHU 700 consists of three models The EHU 701 703 and 704 The maximum capacity of the series is 240 Ibs hr To allow the Series EHU 700 humidifier to function to its full capability be certain to install itin accordance with the following Armstrong recommendations For further assistance please contact your local Armstrong representative for the video tape Armstrong Series EHU 700 Humidifiers Installation Operation and Maintenance DANGER ELECTRICAL SHOCK HAZARD HIGH VOLTAGES EXIST INSIDE THE HUMIDIFIER To protect yourself and others from accidental shocks 1 Keep the humidifier locked during normal operation and store the key in a safe location away from the humidifier ALWAYS DISCONNECT THE POWER SUPPLY AT THE CIRCUIT BREAKER OR SAFETY SWITCH BEFORE OPENING ANY COVERS Before servicing the humidifier learn where the high voltage parts are KEEP HANDS AND METAL TOOLS AWAY FROM THESE AREAS Figure 2 1 Figure 2 2
23. OFF AND CALL THE FACTORY BEFORE RE STARTING UNIT To replace the electrodes please refer to the Tank Disassembly and Electrode Replacement Section of this manual Page 33 RECOMMENDED PROCEDURE FOR STEAM GENERATOR TANK AND ELECTRODE REMOVAL CLEANING REPAIR AND REPLACEMENT TANK REMOVAL AND REPLACEMENT ALL MODELS Turn steam generator tank off by pressing tank off button Drain the tank by pressing the drain button It may take five minutes for a full tank to completely drain Once the tank is completely empty turn off the power at the main disconnect or breaker Disconnect the steam hose from the top of the steam generator tank by loosening the hose clamp with a screwdriver or 5 16 nutdriver BE CAREFUL The tank may still be hot to the touch and some steam may still be condensing in the tank Disconnect the power leads at the steam generator with a 7 16 wrench three leads for 3 phase units two leads for single phase See wiring diagram Figure 12 1 for more details Remove the tank from the cabinet by lifting it out of the drain adaptor BE CAREFUL The tank may still contain hot steam or condensate It is preferable that you replace the tank with a new or rebuilt unit and take the current tank to the shop for servicing Install the tank into the EHU by lowering it into the drain adaptor A small amount of high tempera ture grease or silicone lubricant may be used on the drain adaptor o ring to help it seal properly
24. RCUIT When the humidity in the duct reaches the high limit stat set point the circuit will open and the microcontroller will de energize the contactor The diagnostic mode will display the message C04 and the fill solenoid is blocked DRAIN SYSTEM FAILURE This routine checks for a failure to reduce current if the drain valve is energized for more than five seconds If the actual current does not decrease when the microcontroller demands a drain cycle the unit will go into a diagnostic routine This routine will try twice to correct the drain system failure by cycling the drain valve rapidly If the failure is not corrected the unit will shut down The tank off indicator will light the numerical display will show 05 the drain valve failure message and the dry contact will close to activate the remote alarm Drain system failure can be due to a plugged drain valve drain valve solenoid failure scale buildup in the tank or drain piping problems Refer to the maintenance section of this manual for resolution of these problems FILL SYSTEM FAILURE After start up if the fill valve is on and has been on for more than four minutes the diagnostic routine will check the fill valve operation If the actual amp signal is less than the current when the fill valve was opened the unit will go into a diagnostic routine If the problem cannot be corrected a fill system failure will be triggered and the unit shut down The three digit display will
25. abor or any other cost to remove or install said part or product or at Armstrong s option to repayment of the purchase price As a condition of enforcing any rights or remedies relating to Armstrong products notice of any warranty or other claim relating to the products must be given in writing to Armstrong i within 30 days of last day of the applicable warranty period or ii within 30 days of the date of the manifestation of the condition or occurrence giving rise to the claim whichever is earlier IN NO EVENT SHALL ARMSTRONG BE LIABLE FOR SPECIAL DIRECT INDIRECT INCIDENTAL OR CONSEQUENTIAL DAMAGES INCLUDING BUT NOT LIMITED TO LOSS OF USE OR PROFITS OR INTERRUPTION OF BUSINESS The Limited Warranty and Remedy terms herein apply notwithstanding any contrary terms in any purchase order or form submitted or issued by any user purchaser or third party and all such contrary terms shall be deemed rejected by Armstrong Special Warranty Periods are as follows Series EHU 700 Electric Steam Humidifier Series HC 4000 HumidiClean Humidifier and GFH Gas Fired Humidifier with lonic Beds Two 2 years after installation but not longer than 27 months after shipment from Armstrong s factory 2006 Armstrong International Inc Armstrong Humidification Group 816 Maple Street Three Rivers Michigan 49093 USA Ph 269 273 1415 Fax 269 273 9500 527 G 6 06 www armstronginternational com Printed in U S A
26. al to the desired value 15 15 Verify that all of the input output circuits are functioning properly by entering the input output diagnostics mode Press the mode button until the diagnostics indicator lights and wait ten seconds The unit will do a complete self diagnostic check See CO in the diagnostics section of this manual page 20 for more information 16 Turn power off if humidification is not needed 17 Close and lock the doors and store the key away from the unit 16 TROUBLESHOOTING GUIDE CAUTION Disconnect the electric power supply at the circuit breaker or switch whenever the unit is to be inspected or serviced DO NOT USE THE TANK ON OFF SWITCH ON THE HUMIDI FIER BECAUSE THIS SWITCH DISCONNECTS THE STEAM GENERATOR TANK ONLY PRINCIPLE OF OPERATION AN OVERVIEW The Armstrong Series EHU 700 electronic steam humidifier Figure 17 1 converts ordinary tap water to steam and distributes it within Internal the air being humidified to bring the relative humidity up to External Power Disconnect Contactor the desired level Current Sensor Linje The humidity demand is sensed by the humidistat micro i Fill Valve controller converts this demand signal into an amperage d requirement If humidistat demand is above 35 the internal Conteling power contactor closes applying voltage to the electrodes DN i and the fill valve opens to begin filling the tank Water enters Humiaistat
27. alf o ring channel and put it aside for re use On high voltage units lift the barrier assembly out of the bottom tank half Clean the tank halves and the barrier assembly Figure 35 1 if applicable using a scraper stiff bristle brush and or water spray Rinse the unit with clear water If necessary the drain screen may be removed for cleaning by removing three screws and pushing up through the bottom tank connection with a screwdriver handle or other blunt object The drain screen snaps back into place and is SECURED BY THE 3 SCREWS after cleaning BOTH THE BARRIER ASSEMBLY AND THE DRAIN SCREEN SHOULD BE REPLACED WITH NEW PARTS IF THEY ARE UNSERVICEABLE Install one electrode in the top tank half Make sure the small o ring is located at the bottom of the electrode stud Push the electrode through one of the holes in the upper tank half Slowly turn the electrode until it locks in place Thread a nut finger tight onto the electrode stud Repeat this process with the other five electrodes Turn the tank top half upright and rest it on the electrodes Tighten the nuts on all the electrode studs with a wrench so they are just snug Figure 34 1 Install the electrode jumper wires to the studs at the Eg RN PENNE top of the tank Fasten one end of the jumper wire with D As a washer and 1 4 hex nut using 7 16 wrench There are three jumpers on a three phase unit and four jumpers on a single phase unit On a single phase unit
28. could result The use of either a metal conduit or shielded wire is required for all the control and or safety wiring When using metal conduit the conduit must extend the entire length of the wire and the conduit must be grounded at the humidifier cabinet If the conduit does not extend the entire length of the control wire the wiring must be shielded and the following guidelines must be used 1 The wire shields and all unused conductors must be grounded externally to the humidifier cabinet 2 Ensure a good connection between the shields conductors and the metal bar of the humidifier cabinet Additionally a supplied ferrite core must be installed around the control wiring between where the wire enters the humidifier cabinet and the low voltage terminal block Figure 9 1 9 CONTROL HUMIDISTAT The Series EHU 700 is capable of accepting controls signals with the following characteristics a 0 10 Vdc Humidistat Part No A18609 and A18610 H200 or H270 series TA BERG JUMPER SETTINGS b 1 9 3 9 Vdc Humidistat BJ1 CAPACITY STEP Part No C1471 or C1472 225 fast STEP rest BJ2 SIGNAL GROUND 1 2 NOT GROUNDED 4 20mA 250 Q input impedance 23 GROUND BJ3 TANK SELECTOR SINGLE TANK 0 10 Vdc 50 input impedance 25 DUAL Tane BJ4 STAT INPUT SIGNAL SELECTOR 4 ON OFF 0 135 OHM e 0 5 Vdc reaper 7 8 1 9 3 9 0 BJ5 SOURCE TO STAT LECTOR
29. display should read a few points above 40 9 Press the Drain switch Verify that the unit is draining freely 10 Inspect the steam outlet piping Verify that there are no un trapped low spots Also verify that the piping is insulated and properly sloped See Step 8 on Page 7 11 If the Dispersion Tube is equipped with a drain fitting verify that is working 12 Verify operation of high limit humidistat and or air proving switch if used a If high limit is used turn dial to minimum setting 1096 Display of unit should read CO4 and unit should stop steam production Turn humidistat dial to maximum of 9096 and unit should return to normal operation If pressure switch is being used verify airflow condition in duct or air handler f air flow is present unit should be in normal operation Disconnect wire from terminal 15 at humidifier Display should show and unit will stop operation Reconnect wire to terminal 15 and unit should return to normal operation If Air Flow is not present in Duct or Air Handler unit should be sitting IDLE and Display should be showing CO3 Turn fan on and verify duct or Air handler now has airflow present Unit should return to normal operation 13 While humidification is being demanded turn humidistat dial down to near zero The following should happen a The stat demand reading will decrease to zero b The unit will shut down lighting the Tank Off light 14 Turn humidistat di
30. dures This includes distilled de ionized and reverse osmosis diffusion treated water Most tap water is conductive however so it will work in an EHU If tap water is not available consult with the factory How does this affect maintenance Figure 23 1 Tank filled with mineral buildup Generally the more conductive the water is the more minerals there are dissolved or suspended in it As the water is boiled away these minerals can be left as a deposit on the electrodes tank and fittings Any deposits that build up can block valves diminish the internal volume of the tank and form an insulating barrier on the electrodes Figure 23 1 The EHU automatic drain cycle All Series EHU humidifiers have a built in blow down circuit to intermittently purge excess mineral accumulations from the water The drain cycle should automatically adjust for variations in water quality Eventually however minerals will accumulate in the steam generator and have to be removed see tank cleaning in the maintenance section of this manual Water treatment guidelines for the EHU Generally the EHU will work with any potable water source If you are experiencing problems with your installation however the following suggestions may be helpful in identifying and rectifying your difficulty WHEN WATER CONDUCTIVITY IS TOO LOW Indicators Unable to reach humidity set point in space High water level in tank Low current draw and low 96 power reading
31. e thread adaptor must be supplied by the customer for attaching the piping to 703 or 704 tanks Figure 8 2 SUM A 172 to 174 reducer will be required to connect the dispersion tube to the steam pipe of Models EHU 703 704 Figure 8 5 Figure 8 3 6 Water Seal The steam pipe must be free of kinks and sags to allow for gravity drainage of condensate Provide pitch of 1 per foot towards the unit Pipe supports may be required to accomplish this Insulate the copper tube to minimize condensation Figure 8 4 The preferred installation of the dispersion tube is above the humidifier with a maximum piping run of 20 feet or less Figure 8 3 Figure 8 4 shows the correct installation when 1 You cannot achieve a 1 per foot reverse slope of the piping 2 Piping runs range from 20 to the Figure 8 5 maximum of 40 feet of equivalent run a 3 Elbows or vertical risers must be placed in the piping 4 The steam dispersion tube MUST BE below the humidifier For this installation 1 use a 174 copper tee for the drain Ni connection of an EHU 701 or a 172 Copper Tubing copper tee for EHU 703 or 704 Figure 8 5 CONTROL WIRING NOTE Wiring to the low voltage controls should not run in the same conduits as the power supply wiring because faulty signals
32. e 11 1 and Figure 12 1 the overall wiring diagram for more information Complete installation and wiring instructions are contained in the duct pressure switch package NOTE LIMIT SWITCHES HIGH LIMIT AND AIRFLOW SWITCHES OPEN ON FAULT 11 12 1 Low Voltage Low Energy Controls Main Control Humidistat High Limit Humidistat Air Flow Switch N O Alarm Relay Must be closed to run 24 VAC Drain Valve A 24 VAC Fill Valve High Water Switch A Panel Switches Drain Tank On Off On Off olo ojo Mode Select 5 Micro Controller Printed Circuit Board 27 28 P2 1 10 21 Steam Generator A Current Transformer PAL Three Digit Numerical Display 24 V Secondary Power Transformer 12 AUDIBLE ALARM There is an external alarm circuit provided When an alarm condition is detected in the diagnostic routines a relay contact closes allowing activation of an external Class device connected between terminals 27 amp 28 This circuit is rated to 1 amp Contactor High Voltage Terminals 12 INSTRUMENT PANEL The Mode select button is depressed for approximately 72 second to switch both the display mode selected indicator and the 3 MODE BUTTON digit display between INDICATOR DEMAND of humidistat control range and DISPLAY CURRENT actual current in amps SIVE POWER ratio o
33. e times and the diagnostic mode indicator will light Note the diagnostic message and refer to the diagnostics information in the troubleshooting section of this manual page 20 If the stat demand is less than 35 force a 100 humidity demand by setting humidistat dial to 95 RH Alternately a 100 demand can be simulated by setting BJ4 jumper to position 3 4 on off set BU5 to position 1 2 5 VDC and installing a jumper between terminals 17 1 of the low voltage terminal block inside humidifier 7 Let the unit continue to fill and allow the water to boil a If the water level reaches within 4 of the Steam Generator Tank top the High Water Float Switch will block the fill and illuminate the High Water light momentarily This is normal on relatively pure water Pressing the mode button to check the diagnostic display will result in an indication of CO1 To complete the start up testing in this instance push the Drain switch to drain 1 2 of the tank Next turn off power at the breaker or safety switch and add one pinch 1 2 teaspoon of Epsom salts to the Fill Cup See Part 25 on Page 28 This should allow the water to boil by increasing the water s conductivity See Water Quality and Treatment for EHU Humidifiers in the troubleshooting section on page 23 Reapply power to energize the humidifier 8 On typical beginning fill after the fill stops press the mode button until percentage of maximum power is indicated The numerical
34. ed crack open a fitting between the backflow preventer and the fill valve If this causes the fill valve to open remove the backflow preventer from the system Backflow preventers not needed as the Series EHU 700 incorporates 1 inch air gap as an anti syphon feature For additional information on Armstrong Series EHU 700 Humidifiers contact your Armstrong Representative and request Bulletin No 596 35 HUMIDISTAT DATA AUTOCAL PROCEDURE 1 Measure the room humidity near the humidistat with an accurate hygrometer 2 Turn the humidistat set point dial to match the reading of the hygrometer 3 Push and hold the Autocal button for more than 3 seconds or until the internal red light turns On and Off SENSOR FAILURE PROTECTION The sensor is the most sensitive part of the humidistat and also the most exposed In the case of a sensor failure in humidification mode the humidistat will automatically assume a fail safe output of 0 SPECIFICATIONS Operating Conditions 5 C to 50 C 32 F to 122 F Control 0 to 95 non condensing e Sensor 0 to 100 R H see Note 1 Resolution 0 1 Repeatability 0 5 Accuracy and sensor interchangeability 2 from 0 to 100 Range 10 to 90 R H for 5 to 50 C 41 F to 122 F Temperature effect 0 05 F Outputs Isolated Triac 30 Vac at 2 0 to 5 VDC into 1 KQ resistance min 0 to 10 VDC into 2 KQ resistance min 0 5 VDC
35. en the best location is beside a thermostat that controls temperature in the same space that is to be humidified if that loca tion meets the following criteria e The control humidistat should be located where it will be exposed to the average air condition of the space to be humidified e Avoid areas of restricted air circulation or locations where the sensor will be subjected to air drafts localized heat or moisture sources e Locations near coffee machines computer blower outlets doors to other rooms or windows that can be opened are not suitable 10 11 1 On Off Humidistat 1 9 3 9 Switch Opens on RH Rise Voltage Source 17 Black Part No Voltage Source Part No Ground 2 hite C1471 Ground 8581 Statin 1 Green or Stat In or N C 20 C1472 N C A8581A Set Stat Input Selector to 1 9 3 9 Set BJ4 Stat Input Selector to On Off Set 5 Voltage Source to 12 Vac Set BJ5 Voltage Source to 5 4 20 mA amp 0 10 Setting 0 135 Ohm Potentiometer Part No Voltage Source 47 Voltage Source A6707A Ground 2 Ground or Stat In 1 Stat In A18611 N C 20 N C Humidity ed Increase Set BJ4 Stat Input Selector to Set BJ4 Stat Input Selector to 0 135 Ohm 0 10 Vdc or 4 20 mA Set BJ5 Voltage Source to 5 See Figure 10 1 for Armstrong 0 10 Vdc Humidistat Connections Duct Mounted Control
36. erate but no water drains out TURN THE POWER OFF then a Check for a plugged drain valve and or plugged drain adaptor It is often possible to see an accumulation of solids in the inlet to the drain valve or in the neck of the steam generator If this is the case remove the generator and clean out the drain valve and tank drain adaptor See tank removal section on Page 33 34 b While the tank is out look into the lower end of the tank Make sure the drain screen is place Also check for accumulations of lime at the bottom of the tank Refer to Steam Generator Disassembly and Cleaning Procedure sections to rectify these problems 3 If the tank drains well when the water level is high but poorly or not at all when it is low check the duct pressure where the dispersion tube is mounted A negative duct pressure can cause drainage problems While this is relatively rare it has been known to happen 4 Ifthe water backs up into the drain pan inside the unit check for a blocked drain cup under the pan If the drain cup is OK check the drain piping for an accumulation of solids Clean as required and increase the pitch of the drain piping if necessary If long runs of horizontal drain pipe cannot be avoided it may be necessary to develop some kind of drain flushing system An air gap in between drain piping and drain hose from the EHU will allow burping of air from drain piping Fill System Failure Make sure the drain valve is no
37. f current draw to the CURRENT nominal rating of the unit POWER DIAGNOSTIC MODE readout of diagnostic DIAGNOSTIC codes Leaving the display the diagnostic mode for 10 seconds initiates HIGH WATER the input output diagnostic routine see Diagnostics pg 20 TANK OFF The 3 digit display also exhibits a diagnostic code in the event that the unit has shut down automatically MODE SELECT TANK ON OFF DRAIN ON OFF FILL LIGHT Indicates when the fill valve is energized to add water to the steam generator DRAIN LIGHT Indicates when the drain valve is energized to drain water from the steam generator HIGH WATER LIGHT Indicates that the water level in the generator has risen to the high water level TANK OFF LIGHT Indicates when power to the generator has been interrupted tank contactor open TANK ON OFF Depressing the tank on off button for 7 second will open the tank contactor The tank off light and the diagnostic light will be on and the display will show the message 8 The unit will stay in this mode until the button is pressed again MANUAL DRAIN Depressing the manual drain button for second will open the drain BUTTON valve The tank will continue to drain until the button is pressed again 13 START UP PROCEDURE FOR ARMSTRONG SERIES EHU 700 HUMIDIFIERS The following steps should be performed on all newly installed Series EHU 700 Humidifiers to ensure that the humidifier and the entire humidi
38. fan interlock switch These devices prevent 7 Fei vave Seni excess moisture and condensation in the duct by opening the tank contactor if there is too much humidity or insufficient air Controlling Humidistat 1 flow within the duct m High Limit Humidistat Fan Interlock 1 High Water Controller Float Switch L Drain Valve Overflow Line 17 A high water float switch prevents water carry over into the duct due to an excessive water level in the tank When the high water limit is reached the HIGH WATER light comes on and the fill valve is blocked until some water is boiled away and the water level drops This is common during startup If the high water light comes on and the water level is in the lower half of the steam generator contact the factory for assistance This is due to high static pressure Installation of fill cup extension kit could be required If an overcurrent situation is detected the overcurrent protection circuit will drain water from the tank to reduce current flow If the overcurrent persists the contactor will be de energized to stop all current flow The Series EHU 700 patented automatic capacity adjustment feature eliminates manual adjustment and improves humidity control This feature automatically adjusts maximum output up or down depending on the humidity demand history When the unit is first turned on the maximum output is 40 If the demand stays high the unit automatically steps up the maximu
39. fication system functions correctly BEFORE TURNING ON THE POWER Figure 14 1 1 Examine the wiring and the components in the electrical compartment 2 Check for any loose wires or quick connect terminals that may have been pulled loose 3 Using a screwdriver TIGHTEN ALL SCREW TERMINALS on the power supply terminal block ground lug and contactor Figure 14 1 Make sure all steam generator tank connections are tight Remember a loose joint is a HOT joint and could be a Current fire hazard Transformers 4 Locate the low voltage terminal block Figure 14 1 Verify that an airflow switch is Contactors connected between terminals 9 and 15 or that there is a jumper installed If an airflow switch is installed ensure that there is airflow igh ae k Verify that high limit stat is connected between terminals 10 and 14 or that a jumper is installed Low Voltage 5 Turn on the water supply Check for Terminal Block leaks TURN ON POWER AT THE CIRCUIT BREAKER 6 The following should happen a The Demand Mode and Tank Off lights will be illuminated The stat demand will be displayed b If the stat demand displayed is greater than 3596 the Tank Off light will go out and a few seconds later the Fill Light will go on The unit will begin to fill 14 If the stat demand display is greater than 35 and the unit does not begin filling press the mode select button thre
40. he tank It will vary in drain duration to adjust for changes in water quali ty demand history and steam output Manual Drain Mode If the manual drain button is pushed while the tank circuit is energized the fill valve will also open to temper the drain water If the tank is off only the drain valve will open 19 EHU 700 DIAGNOSTICS THE Series EHU 700 has built in diagnostics to detect system problems early before they become severe If possible the diagnostic routine performs corrective measures If necessary the unit is shut down and a dry contact is closed to enable a remote alarm The diagnostic messages that result in the unit being shutdown are displayed automatically The other messages are displayed when the diagnostic display mode is selected with the mode switch If the dis play mode selection is left in the diagnostic mode for 10 seconds the Input Output circuit diagnostic check will begin DIAGNOSTIC DISPLAY MESSAGES Coo C01 C02 C03 C00 NORMAL OPERATION C01 HIGH WATER C02 TANK NEEDS CLEANING C03 INTERLOCK CIRCUIT C04 HIGH LIMIT CIRCUIT C05 DRAIN SYSTEM FAILURE C06 FILL SYSTEM FAILURE C07 OVERCURRENT FAILURE C08 MANUAL TANK SHUT OFF C09 I O DIAGNOSTICS Automatic shutdown and Alarm contact closure NORMAL OPERATION HIGH WATER A high water float switch prevents water carry over into the duct due to too high a water level in the tank When the high water limit
41. ice Armstrong cannot guarantee that new parts will fit your used parts See Drawings on Page 28 25 Valves and Mechanical Parts Item Part No Description Used On 168 B2582A 2 Float Switch Assembly Far Tank 74 Fill Valve w Flow Washer amp Straight 3 8 Compression Fitting 198 C2078 __ Drain Adapter Less O Ring 703 704 Screw Drain Cup 10 32 2 Long Tube Fill Valve to Fill Cup 27 1 2 x 3 8 Tube Fill Valve to Fill Cup Tee 1 1 2 x 3 8 Reinforced Tube Fill Cup Tee To Cup 1 21 x 3 8 Tube Fill Cup Tee To Cup 2 38 x 3 8 Tube Fill Cup Overflow 31 x 5 8 Tube Fill Cup to Tee 9 1 2 x 5 8 Tube Tee to Float Switch 10 1 2 x 3 8 Tube Tee to Float Switch 17 x 3 8 Tube Tee to Adapter 12 1 4 x 5 8 Tube Adapter to Drain Valve 1 3 4 x 5 8 B2740 Control Tee Fill Cup Tee 82578 Float Switch Chamber Bracket 701 703 704 Steam Hose ID 1 1 2 x 9 5 8 B2716 18 1 1 2 Steam Hose Clamp Pipe Tee 5 8 x 5 8 x 3 8 Item Not Shown See Drawings on Page 28 26 Electrical Parts Item Part Description Used On 46 701 703 704 701 478 703 704 56A 701 568 703 704 56C 704 57A 701 57B 703 704 58B 58A Tank Jumper Lead 10 1 Ph 703 704 Tank Jumper Lead 14 1 2 3 Ph 703 704 Not Shown See Drawings on Page 28 27 Figure 28 1 EHU 700 Parts List 23 40 29 56
42. igure 35 2 tank half Figure 35 2 5 The mounting hole on each electrode is attached to the tank top with a slotted self tapping screw 6 From the outside install a flat washer and 4 hex nut on each electrode stud Tighten these with a 7 16 wrench so they are just snug Figure 35 2 FILL AND DRAIN SYSTEM REPAIR General In the event of a drain system failure C05 or a fill system failure C06 indication on the three digit numerical display perform the following steps to identify and correct the fault Drain System Failure Check for drain valve operation With the unit on press the tank on off button turning off the tank con tactor tank off light illuminated Press the manual drain button The drain light should go on and you should hear the drain valve operate with a sharp click Repeatedly activate the manual drain button to determine if the valve is operating 1 Ifthe drain valve does not operate but the drain light is on check for 24 VAC between the two leads on the drain valve Figure 28 1 28 2 After checking TURN THE POWER OFF If 24 VAC was NOT found check wiring continuity to the circuit board Repair broken wires as necessary If wires are intact call the factory for assistance b If 24 VAC WAS found measure the coil resistance of the drain valve with the leads disconnected The coil resistance should be 10 ohms if it is not replace the drain valve 2 Ifthe drain valves can be heard to op
43. leaning Fill and drain valve nennen TANK DISASSEMBLY ELECTRODE REPLACEMENT EHU 703 704 EHU 701 single and three phase HUMIDISTAT DATA Autocal Procedure Sensor Failure Protection High Limit Humidity Sensor Humidity Set Point Reset by Outside Temperature ONNNDDAA HRA BND 13 14 17 17 18 20 23 23 23 24 25 25 29 29 30 31 33 33 34 36 36 36 38 38 PRE INSTALLATION 1 CHECK SHIPMENT Acclaim should be filed with the transportation company and reported to Armstrong if any items are missing or damaged Your shipment will arrive in two or three cartons One carton holds the humidifier with the steam generator installed the control humidistat and sensing element two short steam hoses hose clamps mounting plate and lag screws and a clear drain hose If you have ordered a duct pressure switch or a high limit stat these too will be in the humidifier carton The steam dispersion tube s and fittings are contained in another carton two for the EHU 704 Two complete sets of Figure 4 1 EHU 701 installation instructions have been shipped with your unit One is for the installer s use The second is for the owner s files PENNE Side Clearance 2 CHECK LOCAL CODES Both Sides 3 Series EHU 700 humidifiers
44. light brown colored mineral buildup This buildup may be anywhere from soft and chalky to rock hard The automatic drain cycle will minimize mineral buildup but eventually the tank will need cleaning Tank cleaning is indicated when a The unit has been in service for a period of time a solids buildup is visible through the tank walls and the normal water level in the tank is rising or b The tank cleaning message C02 is displayed TO CLEAN THE TANK PLEASE REFER TO THE TANK REMOVAL AND REPLACEMENT AND THE STEAM GENERATOR CHEMICAL CLEANING PROCESS SECTIONS OF THIS MANUAL PAGE 30 Tank Replacement Tank replacement is indicated if the tank body becomes deformed in any way as this could cause leakage around the o ring TO REPLACE THE TANK PLEASE REFER TO THE TANK REMOVAL AND REPLACEMENT SECTION OF THIS MANUAL Page 30 Electrode Replacement Electrode disintegration generally starts due to high conductivity water being present in the steam generator Electrode disintegration sometimes occurs as a result of a combination of the following factors a High voltage especially 480 and 600 volts Hard water in excess of 20 grains gal Any unit with a malfunctioning drain system Softened water b 29 If the electrodes begin to disintegrate the tank may turn black or red and arcing or flashing may be visible inside the tank while it is operating IF YOU NOTICE EXCESSIVE ARCING SHUT THE UNIT
45. limit humidity sensor is installed in the supply duct An outdoor temperature sensor is installed in the fresh air duct Humidistat model number H270 69 13 10 31 figure 42 1 Alternative humidistat wiring 17898 H270 6 10 Ft On Off High Limit Humidistat optional Air Flow Switch optional Humidifier Connection Outside Air Humidifier L E Location output gt 13 0 to 10 Vde 4 14 7 gt Exhaust Air Humidifier INPUT Main Humidity Sensor Connections MAIN SENSOR 7 MA 8 10 Vde 39 Dimensional Information Conn for Conn for Dispersion Dispersion 2 ID 1 1 2 ID Hose lP EHU 703 EHU 704 Dimensions 7 Aue dct EE in mm in mm in m l A8 Tank42Drain Front 2834 790 l Steam Outlet 2 2 _ 4 36 J Water Supply Side L Electric Supply Side 38 80 2 951 2 5 Water supply connection 3 8 compression Fill rate 31 gpm Unit is designed to mount on 16 centers 2 Lag screws amp Bracket are provided for EHU 70
46. m output and will reach 100 maximum output after one hour For test purposes or for special operating situations this fea ture can be easily over ridden by changing the position of jumper BJ1 on the printed circuit board from pins 1 and 2 to pins 2 and 3 An automatic drain cycle blows down mineral laden water to increase steam generator life and reduce maintenance requirements The frequency and duration of the drain cycle will vary with supply water conductivity steam output and humidistat demand history When it is initiated automatically the drain valve cycle occurs at the beginning of a fill cycle The incoming cold water tempers the drain water to less than 160 F after 72 hours of no demand the unit will initiate an End of Season drain to remove stagnant water OPERATIONAL GUIDELINES This section describes the conditions and indications you should expect to find in a normally operating humidifier Tank Contactor Operation The microcontroller will de energize the contactor turning off the current to the electrodes if ANY of the following occur 1 The control humidistat demand signal is less tan 25 2 The fan interlock circuit is open 3 The high limit humidistat circuit is open 4 The tank current is greater than the over current limit Conversely the microcontroller will energize the contactor turning on the current to the electrodes only if ALL of the following occur 1 control humidistat demand signal is
47. ons stay in solution causing the conductivity of the water in the tank to increase rapidly CAUTION Soft water may increase the tank s water conductivity and does not allow a protective coating to form on electrodes Also as salts stay in solution more drainage will be needed to maintain correct water conductivity in the tank Please consult factory for softened water analysis if softened water source is available before proceeding Expect to replace electrodes more frequently Discontinue service if continuous arcing or foaming occurs in the tank 24 EHU 701 703 704 Series Electronic Steam Humidifier Repair Parts Steam Generators Complete Part No Description Used On 1 Ph Low Voltage 120 208 240 277 Volts 1 Ph High Voltage w Barrier 7 380 480 600 Volts 01 01 01 7 D4416 3 Ph High Voltage w Barrier 380 480 600 volts D262A 3 Ph 1 Ph Low Voltage 120 208 240 277 volts 703 704 D262 3 Ph High Voltage w Barrier 380 480 600 volts 703 704 Note A replacement generator comes with a spare drain adaptor O Ring Steam Generator Parts Item Part No Description Used On Electrode Replacement Assembly 1 Ph A10077 Electrode Replacement Assembly 3 Ph Electrode Replacement Set Includes 6 ea electrodes O Rings 1 4 Nut amp 1 2 1 Ph 3 Ph C2053 Not Shown T These parts are furnished as a convenience to our customers Part dimensions may change in serv
48. serve the following a Make certain there is a manually operated interlocking circuit breaker or safety switch not furnished in the electric service ACCESSIBLE TO AND WITHIN SIGHT OF THE HUMIDIFIER b USE ONLY WIRE WITH COPPER CONDUCTORS RATED 90 C OR HIGHER FOR HIGH VOLTAGE AND GROUNDING c Pass high voltage ground lead through provided ferrite core AN between where it enters the cabinet and where it connects to ground lug d Ground the humidifier cabinet a ground lug is provided in the wiring compartment able 6 erie DO Capa es and Ele al Rating Nom Recommended Output Per Hour Voltage Shown Amp Current Branch Circuit Single Phase Three Phase Rating Module Circuit 120 208 240 277 208 240 346 380 415 480 600 Breaker Ib Ib kg Ib kg Ib Ib kg Ib kg Ib Ib Ib kg Ib kg Ib k aifer One Small Steam Generate 7 14 15 2 0914 18 5 23 6 27 7 132 8 36 12 541 13 6 15 68 17 77 21 95 12 12 14 15 4 18 7 32 8 36 10 45 12 54 14 63 21 9 5 23 10 4 25 11 3 29 13 2 36 16 3 14 14 12 20 5 23 8 36 10 45 11 5 15 68 17 77 24 10 9 27 12 2 29 132 34 15 4 42 19 16 CM16 12 20 6 27 10 45 11 5 13 6 17 77 19 86 28 12 7 30 13 6 33 15 38 172 20 CM20 10 25 12 54 14 63 16 7 3 21 9 5 24 10 9 35 15 9 38 17 2 42 19
49. sp Duct Width DISPERSION TUBE NOTE Please Disp Tube Tube Length Min Max Weight contact factory for duct applications Model No in mm in mm in mm kg offering high static pressures 4 WC f 304 279 406 14 457 432 559 1 4 609 584 864 2 a Verify that the proper length and type of 914 889 1168 3 steam dispersion tube has been selected 1219 1194 1473 3 6 See Chart 7 1 for proper dispersion tube 1524 1499 1778 4 lengths The low capacity dispersion 1829 1803 2083 2133 2108 2388 5 tube Figure 7 2 is sloped toward the gt TT 35 2093 generator to allow for gravity drainage 2742 2718 2998 On applications where the humidifier output capacity is greater than 40 Ibs hr a high capacity tube with a 72 O D drain tube must be used Figure 7 3 Drain tube must have minimum 6 water seal see Fig 8 3 9 22 4 Places 5 25 b Select a location on the duct that provides adequate length for vapor mixing and the shortest connection length for vapor For Saanaa mixing and the shortest connection length 40 lb hr or Less to the humidifier Preferably the location should be 6 downstream and or 10 feet upstream from any dampers vanes bends in the duct or controllers i e high limit stat See page 10 for details Do not install the dispersion tube into ducts in which airflow exceeds 2 000 fpm Do not restrict airflow in
50. t leaking A leaking drain valve may appear to the humidifier as a fill system failure Check to see that the fill valve is operating While the fill light is on disconnect one of the fill valve leads Figure 28 1 28 2 then momentarily touch the lug to the coil terminal You should be able to hear the valve operate 1 Ifthe fill light is on but the valve is not operating check for 24 VAC between the valve lead wires After checking TURN OFF THE POWER a If 24 VAC WAS NOT found check the continuity of the wires back to the circuit board Repair broken wires as necessary If wires are intact call the factory for assistance b If 24 VAC WAS found disconnect the fill valve leads and check the coil resistance It should be 18 ohms Replace the coil if necessary 2 Ifthe fill valve is operating but the unit fills too slowly check for either low water pressure less than 25 psi or a partially plugged screen inside the inlet fitting If the screen tends to plug too easily it may well be removed and replaced by a larger filter in the water line external to the unit NOTE the nominal flow rate valve should be 0 31 gal min for each tank The flow rate is regulated by a flow washer in the valve inlet or on the EHU 704 by flow washers in the brass tee immediately downstream of the fill valve 3 Ifthe valve makes humming or buzzing noises but fails to open a Check for high water pressure over 125 psi b If a backflow preventer is us
51. to these problems MANUAL TANK SHUT OFF The tank on off button will de energize the tank contactor The tank off light and the diagnostics indicator will be on and the display will show the message C08 The unit will stay in this condition until the button is pressed again In the tank off mode the manual drain button is still active but the mode select button is not 21 09 DIAGNOSTICS If the display mode selection is left in the diagnostic mode for 10 seconds the Input Output circuit diagnostic check will begin The display will show the message 09 the tank will be off and the diagnostics mode light will remain on Output Circuits The diagnostics will first check all the output circuits fill valve drain valve and tank contactor to make sure they are working When a light comes on you will hear the corresponding valve or contactor circuit energize for about 2 seconds Each circuit is checked twice before proceeding to the next circuit Input Circuits Next the microcontroller checks the status of all input circuits beginning with the control stat the 3 digit display will show 0 Demand then the actual stat demand It will do this twice The input diagnostics continues by checking the fan interlock switch high limit duct humidistat and high water switch The display will now show 09 followed by any additional messages that indicate problems with the input circuits When the I O diagnostic check is finished
52. you should have only two loose ends Figure 34 1 Install the o ring in the bottom tank half o ring channel A third hand or weight may be needed to hold one end of the o ring in place while the other end is being installed 10 Install the barrier assembly in the bottom tank half 11 Lower the top tank half onto the bottom tank half Line up the marks on the rim of the top and bottom tank halves to properly center the electrodes 12 Look trough the top connection to make sure the o ring is still in place 13 Snap a metal clip over the flanges of the tank halves midway between two alignment marks Position another clip on the opposite side of the tank Install all 24 clips in this manner 33 MODEL EHU 701 SINGLE AND THREE PHASE Figure 35 1 1 Remove 24 metal clips by pushing gently on top of each clip with a screwdriver while cupping the clip with the other hand 2 Clean the inside of the steam generator thoroughly Barrier Retainer unsing a scraper stiff bristle brush and or water spray and rinse with clear water 3 High voltage units are supplied with a barrier drain screen assembly in the lower tank half to increase tank life Inspect the barrier drain screen assembly and replace if 3j Ve Drain Screen necessary 4 Place a flat washer and O ring on each electrode stud and push the studs through the holes in the upper F
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