Chromalox CAS-20CM Boiler User Manual
Contents
1. 0 160 PSIG SOLID STATE LEVEL CONTROL PARTS Description Probe Level Control 5 Probe Cutoff 57 351 118664 003 130 118661 001 Part Number 242 300036 010 242 300036 011 Control Board with Relay 2 probe Control Board 1 probe Control Board 3 probe 323 300033 001 323 300033 011 323 300033 006 Relay for Control Board Plug in Spark Plug 072 300047 001 346 300035 001 Probe Isolator For Level Control Used on older models 332 300009 002 Limited Warranty Please refer to the Chromalox limited warranty applicable to this product at http www chromalox com customer service policies termsofsale aspx Chromalox PRECISION HEAT AND CONTROL 2150 N RULON WHITE BLVD OGDEN UT 84404 Phone 1 800 368 2493 www chromalox com2. depending on the function and the water level ADJUSTING PRESSURE CONTROLS Chromalox boilers are supplied with operating and high limit pres sure controls One is used for controlling the operating pressure of the boiler while the other is used as a high limit control MANUAL BLOWDOWN INSTRUCTIONS Blowdown is an essential part of boiler operation It is the best preventive maintenance you can give your boiler and will add years of life to the unit Make sure a blowdown schedule is estab lished and followed regularly Blowdown will remove accumulated hard water scale and dis lodge scale from water heating surface thereby insuring efficient heating In extremely hard water areas blowdown is necessary once a day In soft water areas once each week If water is known to be corrosive consult water treating specialists to recommend water treatment needed to insure corrosion free boiler operation If there is a particular problem which applies to your own local water condition other than mineral content take this into consideration in determining what schedule is to be followed 1 At the end of the working day turn switch to the OFF position and close water supply valve De energize wall mounted safe ty switch main power supply 2 If blowing down into a receptacle cover receptacle to prevent splash of scalding water 3 It is preferable to connect the blowdown valve directly into a drainage system If this is done the boiler can be disc
3. boiler to the proper water level and automatical ly shut off The feed solenoid will continuously cycle on and off as the boiler requires water If for any reason the water drops below the minimum safe operating level the boiler s electrical circuits except the feed solenoid will be de ener gized automatically Upon refilling to the proper level the boiler will automatically restart SCHEMATIC WIRING DIAGRAM Wire Color Code B Black W White R Red O Orange Y Yellow GR Green BL Blue Water Level Control Probe and Isolator Assembly Or 1 Power Supply 120V Control Circuit To Heating Element 30 Power Supply Low Water Cut Off Probe Heating Element A Spark Plugs To Heating Element OPERATION SOLID STATE FLOATLESS LIQUID LEVEL CONTROL SYSTEM This boiler is equipped with a solid state floatless liquid level control which operates by sensing the electrical resistance of water Note Control will not work with de ionized or demineral ized water Two probes are provided The HI probe activates and controls the feed water relay The LOW probe is a safety back up probe that turns off the power to the element in the event of low water A 12 volt potential is established between each probe and ground The presence or absence of water generates a small signal that is amplified and fed to a SCR The SCR in turn activates a relay
4. Chromalox Installation Operation SERVICE REFERENCE wem semon eas and REFERENCE Supersedes P0435 PQ435 1 RENEWAL PARTS IDENTIFICATION pate JUNE 1994 Type CAS 20CM Electric Steam Boiler Standard Trim is 100 PSI 0 90 PSI Operating Pressure Range ES gt S 4 NS Boiler Serial No Power Circuit Voltage Model No Control Circuit Voltage National Board No Amps Phase IMPORTANT This data file contains the National Board Registration Certificate approving your boiler It must be kept near the boiler at all times Moe Electric Capacity BHP Rating Voltage Amperes Drawn Contactor 20 kW i 208 50A 4 Pole 16 20 kW 208 230 60A 3 Pole CAS 20CM 20 kW 240 50A 4 Pole 20 kW 346 40A 3 Pole 20 kW i 380 60A 2 Pole 20 kW 480 30A 3 Pole Note Control circuit 120V 2010 Chromalox Inc INSTALLATION WARNING To avoid electrical shock hazard boilers must be suitably grounded to earth Note Chromalox boilers are pre tested before shipment no inter nal piping or wiring is necessary WARNING Substitution of components or modification of wiring without prior consent of Chromalox voids warranty 1 Bolt unit securely to level floor or platform Note A minimum distance of 18 inches from wall other equipment etc must be allowed for removal of the elements 2 Complete all piping to boiler Connect water line to tagged fit ting on the motor and pump assembly
5. ctions moan 2 8 20kW 240V 1PH 20kW 208V 1 3PH 155 300121 006 155 554735 023 16 20kW 208 230V 3PH 20kW 346V 1 3PH 155 554735 024 155 554735 051 20kW 380V 1PH 20kW 480V 3PH 155 554735 042 155 554735 030 Element Gasket Element Bolt 6 Req d ELECTRICAL COMPONENTS Rocker Switch with Pilot ON OFF Contactor 30A 3 pole 132 146012 001 345 072565 428 292 053223 002 072 047913 020 Contactor 40A 3 pole Contactor 50A 4 pole 072 047913 012 072 047913 021 Contactor 60A 2 pole Contactor 60A 3 pole 072 047913 026 072 047913 016 Fuse Holder Terminal Block Control Terminal Block Power 1 PH only 129 300029 001 303 075444 001 Fuse 15A 250V GAUGE GLASS PARTS Sight Glass 303 047468 003 128 072576 027 Part Number 374 121046 021 Sight Glass O Rings Valve Set 132 073284 001 344 120970 003 Sight Glass Protector 334 056360 002 Nipple Conduit 1 198 300084 004 RENEWAL PARTS IDENTIFICATION HEATING ELEMENTS PRESSURE CONTROLS Description Operating Pressure Control Auto Reset High Limit Pressure Control Auto Reset VALVES AND GAUGES Description Safety Valve 14 100 PSIG Check Valve 34 Part Number 292 300031 001 292 300031 001 Part Number 334 300032 004 344 118536 005 Drain Valve 1h Solenoid Valve 120V 14 NPT 344 121194 006 344 121780 012 Strainer 4 Pressure Gauge 4
6. er system of boiler Again note wire connections to facili tate re assembly Proceed to remove 6 18 bolts from flange 5 Thoroughly clean boiler flange of all foreign material Be cer tain no part of old gasket remains on boiler flange Apply Slic Tite Gasket Compound or equivalent to both surfaces of new gasket supplied with replacement element Proceed to install element flange assembly with gasket between boiler flange and element flange In doing this be careful to align flange holes element flange is marked TOP so wire connection terminals on top element assembly will be in line with previously disconnected wire leads to facilitate easy connections When all 6 flange bolts are tight connect all wires to termi nals Make certain wires are clean and bright to assure good electrical contact and nuts on screws are firmly secured Note Bolts should be tightened to a torque of 22 ft lbs Open water valve so water supply can reach boiler feed mech anism 9 Put main safety switch to ON position 10 Turn boiler switch to ON position 11 As boiler automatically refills observe the new flange assem bly for possible leaks If water is noticed the bolts must be retightened Before doing this turn the boiler off at the main fuse safety switch 12 As boiler is heated to working pressure check flange assembly again for leaks WARNING Avoid use of chemical cleaning com pounds Follow maintenance instru
7. fuses between the main power source and the boiler This overcurrent protection should be installed in addi tion to any other supplementary fuses or circuit breakers pro vided as an integral part of the boiler 2 If a separate control circuit is used the control circuit should be connected to the control terminal block and the circuit pro tected by overcurrent devices in accordance with the National Electrical Code 3 Chromalox boilers are solid state devices Since boilers are connected to water lines these devices are susceptible to volt age surges and lightning damage Industrial type lightning pro 2 tectors should be installed per manufacturer s recommenda tions at your service entrance Be sure that all electrical connections are sufficiently tight ened Loose connections will cause overheating and damage to the electrical wiring Special instructions for customers supplying their own con densate or pump system A Check the voltage of the motor before making the wiring connection The motor should always match the voltage of the control circuit Standard control circuit voltage is 120 volts 10 volts Internal water feed relay is rated at a maximum of 4 H P 120 volts Motors rated greater than 4 H P or other than 120V single phase require the use of a suitable motor starter After all service connections are made open feed water supply valve and energize the boiler The feed water solenoid will open fill the
8. harged at operating pressure However check local codes and suitability of drainage system before connecting 4 When blowdown is complete and boiler is drained a close the blowdown valve b open water supply valve c put boiler switch in the ON position and d close wall mounted safety switch 5 When refilling is complete turn off the boiler switch unless further operation is desired The use of chemical boiler cleaning compounds in these boilers voids all warranties unless approved by Chromalox Inc MAINTENANCE WARNING Hazard of Electric Shock Disconnect all power before working on boiler 1 Amonthly inspection should be made to ensure that all electri cal connections are tight When steam or water leaks are observed fittings should be tightened immediately 3 Every four months the Solid State Liquid Control probes should be checked for deposits and cleaned if necessary Remove deposits from probe and teflon sleeve This is accom plished by removing the inspection plate and with the use of a standard spark plug wrench removing the probes Care should be taken during the removal and reinstallation of the probes so the porcelain insulator is not damaged 2 The feed water probe is mounted in a surge isolator tube This isolator tube should be removed and cleaned at the same time as the probes Note Make sure that probe does not touch the insulator tube as grounding will occur This will cause boiler to r
9. if used or to tagged fit ting on water control feeder Type CAS Electric Steam Boiler 1 2 NPT 100 PSIG S Valve 1 2 NPT Steam Outlet Nipple 1 2 NPT Gauge Glass Ass y 3 When any type of feed other than a pump feed is used the water supply line pressure must be 10 pounds greater than the boiler operating pressure to assure proper water level in boiler Lack of water can cause heater failure Keep feed water line valves open at all times Connect steam line with outlet valve to boiler steam outlet Open all gauge valves and steam outlet valve keep drain valve closed Note The safety valve should be provided with a drain line sized no less than the outlet size of the valve and routed per local codes Floor drain to be provided directly below unit Operating Pressure 3 Control 1 2 NPT Pressure Gauge High Limit Pressure Control WIRING WARNING Hazard of Electrical Shock Disconnect all power before working on boiler Boilers must be grounded in accordance with the National Electrical Code NEC standards to avoid shock hazard WARNING Use 90 C copper conductors only 1 Select proper wire gauge and type for supply conductors in accordance with the National Electrical Code and local wiring codes following wiring diagram supplied See recommenda tions for disconnect switches and fusing Note Purchaser should use a safety disconnect employing cir cuit breakers or
10. probe and isolator tube for deposits B Check water feed relay for frozen contacts C Check solenoid valve may be stuck or damaged 5 Element repeatedly burns out A Low water cutoff probe damaged or shorted to ground Remove and check low probe Boiler not supplied with water Check water feed lines valves and circuits Check water feed probe Control board defective Check operation of board and component Replace board if necessary Control board trouble shooting Start up sequence The two probe board has the following sequence of operation when the boiler is initially energized A Turn on control circuit power Approximately 10 second delay before water feed solenoid or pump starts Water rises in boiler and contacts low probe which closes relay contacts turning on heater Water continues to rise to HI probe Turns off water feed B C B C B C D 4 Normal Operation Sequence 1 Water drops below HI probe After 10 second delay water feed energizes refilling boiler 2 Water reaches HI probe and turns off water feed 3 Sight glass should be to full Heater contactor will cycle at operating pressure depending on load Heater contactor should not chatter on short cycle In the event of contactor chatter check for low water condition and check for damaged or short ed probes Inconsistent water level causing low water cutoff 1 Test feed solenoid control circuit by energizing con
11. trol circuit Remove cover plate from probes 2 Check for shorted or failed water feed probes 3 Check water feed lines valves and circuits INSTRUCTIONS FOR ELEMENT REPLACEMENT Note Element failure is usually caused by excessive scale build up or low water operating conditions Before replacing element be sure boiler tank is clean and free of scale Check control board water feed system and control probes for proper operation Failure to perform the above maintenance checks may result in immediate burn out of new elements 1 A monthly inspection of the boilers boiler installation and electrical wiring should be made to insure proper operation These inspections should include A Electrical connections Look for overheated or discolored power terminals Check and tighten all terminals that may work loose from expansion and contraction Check for steam or water leaks and tighten all pipe fittings Check safety relief valve Check water feed line strainers and check valves Blow down boiler and make sure drain lines are clear Read completely before starting work 1 Disconnect boiler from electric power supply at main safety switch or fuse panel Then turn boiler switch to off position On automatic feed units close valve on incoming water line Drain boiler completely of water 3 Remove wiring compartment end panel to expose heating ele ment Disconnect wire electric leads connecting element to main pow
12. un dry At the same time remove the heating element and inspect for scale formation If scale has begun to form clean element and also flush boiler TROUBLE SHOOTING HINTS 1 Boiler does not energize when main switch is turned on noth ing happens A Check to see if main power is turned on Check to see if control circuit voltage is turned on ON OFF switch has a pilot light Check power and control circuit fuses or breakers D Check control circuit fuse on boiler E Check all electrical connection for tightness Boiler power control circuit pilot light is on Boiler will not fill or heat A No water in boiler Check sight glass it should be 4 to 4 full Check water feed lines valves pumps strainer etc for proper operation Solid state water feed probe inoperative Check solid state liquid controls probes Water feed solenoid should activate 10 seconds after control circuit is turned on Clean probe and isolator tube as required Make sure probe is straight and does not touch wall C Water feed relay bad replace plug in relay D Solenoid valve bad replace solenoid valve 3 Boiler has power and water in sight glass Boiler will not heat A Bad heating contactor Check for open coil or frozen contacts B Bad relay on control Board Replace control board C Burned out element Replace heating element D Loose power connection Tighten electrical connections Boiler floods A Check high water
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