Model ACC34AC Signal Conditioner/Converter (AC)
Contents
1. 5 DESCRIPTION A TED SHIELD TO COMMON PWR DES 0 1 84 REDRAWN ON CAD CS DWG NO WAS 34 301 CS DWG NO WAS 700 0120 N lt O N O ATTEN INPUT PULSE INTERSTAGE OUTPUT 12 1 CASE GROUND UNDER SCREW MARA DRAWN PRAWN TE J D 3 83 A REPLACES 700 0120 HOFFER FLOW CONTROLS INC ELIZABETH CITY NC 27909 A WIRING INTERNAL CASE ee ee ACC34 AC TO BE DISCLOSED TO OTHERS TOLERANCES OTHER THAN RAW REPRODUCED OR USED FOR ANY MATERIAL SHALL BE HELD OTHER PURPOSE EXCEPT AS AS FOLLOWS SIZE FSCM DWG REV AUTHORIZED IN WRITING BY HFC 2 PLACE DECIMAL 01 A 34 301 MUST BE RETURNED ON DEMAND ON 3 PLACE DECIMAL 005 SHEET OF 1 NEXT ASSY USED ON APPLICATION PURPOSE FOR WHICH LENT 5521 COMPLETION OF ORDER OR OTHER FRACTIONAL 31 542. NEXT ASSY REVISIONS NOTES ENCLOSURE MEETS CLASS GROUPS amp D CLASS Il GROUPS F amp G NEMA 7 amp 9 OPTIONAL 0 RING REMOVABLE COVER ae 4 7 8 __ mm 3 3 4 1 NPT TYP 2 PLACES HOFFER FLOW CONTROLS INC ELIZABETH CITY NC 27909 2 Pace 1 85321500 0021 FRACTIONAL 1 64 SCALE Peer OF 1 NON ANGULAR 1 2 THIS PAGE INTENTIONALLY LEFT BLANK ACC 34 2 3 HP 245 AC SECTION HI CALIBRATION OF ANALOG OUTPUT GENERAL CONSIDERATIONS INTRODUCTION In general all flow measurement systems by Hoffer Flow Controls have been factory calibrated as specified by the user at the time of purchase free of charge All systems which underwent such a factory calibration have a calibration card attached prior to shipment This card contains the details of analog outputs as well as other useful calibration data Field calibration is only required when a change has occurred or is sought to the measuring system Such a change may be due to repair replacement or recalibration of the flowmeter or perhaps a change in the analog output span PROCEDURE Begin by determining the equivalent maximum volumetric flow rate in GPM expected by the application term this GPM MAX GPM MAX may be calculated based on the analog output scale requirements or may be the maximum flow rate listed on the flo
3. 2 SLNINLSNPOV STOYLNOD MIO 38 2113 ONI STONLNOD MOTI 43330H 034530 Si 39NYHO di 3 LINSNOO ABOLOYI SI 952 821 99 58 9SZ YO 7821799 9 TE 9 330 39 15 S3HOLWAS TIY AINO HOLIMS 123136 LON AWO NOULYUSNTI 303 035538430 St Z HOLMS W130 ONNVIS 3ST1nd 10313S JONVY 3SYO AMOI OLNI 318035535 W130 NIS 35104 193135 JONYY 335 10390 BVIINIS YO N3d LNIOd TWG Y ONEN 4 038530 NO 7 5 LOUD I INFIVOS 35104 193135 3SV AMOT OLNI 3504 TIVISNI gt A30NINWOI3Y LON SUJONLY ONISN 13205 3513 TINA AT AGSSYENS ISNI 31207 7 ATINISSYBNS LOY 3604 LOO AVBNISSY CUNY AAO 1311 Y 3590 30 5306 HOY SWBYOS 3NIHOYN OML Z 330 01 YMOd 181355 815 LUD 031 YAOI 01 SIANOIDOSA SNDIA33S KINO HMOJ OWAOLI 8 72 LON 300 303 034403 HAASOISNVHL ONY ISN 1 ddy 3190 538 3107 S310N SECTION IV ACC34 FREQUENCY CURRENT FLOW CONVERTER SUBSYSTEM INITIAL STARTUP Perform any purging of piping with spool piece in place Once compl
4. of case A multiple turn control used to set the threshold sensitivity level above the ambient noise pickup A dual in line DIP switch located on the PCA 61 board which is used to program the module to accept an input frequency range A multiple turn adjustment which is used to set the voltage output signal to the desired span corresponding to the equivalent flow range 1 4 to 20mA corresponding to 0 100 GPM A multiple turn adjustment which is used to set output signal with no flow to the desired zero value i e 4mA A dual in line DIP switch located on the PCA 60 board which 1s used to set the pulse scaling device factor to 2 4 8 16 232 64 128 and 256 1 2 245 ORDERING INFORMATION MODEL ACC34 A B D E PULSE OUTPUT ANALOG OUTPUT INPUT POWER OPTIONAL FEATURE ENCLOSURE STYLE PULSE OUTPUT MODEL ACC34 A OPTION 1 OPEN COLLECTOR 2 TTL CMOS 3 AC SQUARE WAVE 5 0 10 V SQUARE WAVE ANALOG OUTPUT MODEL ACC34 2 IC IC OPTION 9 NONE C 4 20 MA Cl 4 20 MA ISOLATED INPUT POWER MODEL ACC34 OPTION A 115 VAC 50 60 HZ 220 VAC 50 60 HZ D 15 35 VDC OPTIONAL FEATURE MODEL 34 D OPTION PS DIP SWITCH SELECTABLE DIVIDE BY 2 4 8 16 32 64 128 ENCLOSURE STYLE MODEL OPTION 2 STYLE 2 CASE GENERAL PURPOSE 4 0 STYLE 4 CASE EXPLOSION PR
5. review the complete model of each item to be connected and locate the appropriate manual s and or drawing s Identify all model numbers exactly before making any connections A number of options and accessories may be added to the main instrument which are not shown on the basic user wiring Consult the appropriate option or accessory user manual before connecting it to the system In many cases a system wiring drawing is available and may be requested from HOFFER FLOW CONTROLS This document contains proprietary information which is protected by copyright All rights are reserved No part of this document may be photocopied reproduced or translated to another language without the prior consent of HOFFER FLOW CONTROLS INC HOFFER FLOW CONTROLS policy is to make running changes not model changes whenever an improvement is possible This affords our customers the latest in technology and engineering The information contained in this document is subject to change without notice RETURN REQUESTS INQUIRIES Direct all warranty and repair requests inquiries to the Hoffer Flow Controls Customer Service Department telephone number 252 331 1997 or 1 800 628 4584 BEFORE RETURNING ANY PRODUCT S TO HOFFER FLOW CONTROLS PURCHASER MUST OBTAIN A RETURNED MATERIAL AUTHORIZATION RMS NUMBER FROM HOFFER FLOW CONTROLS CUSTOMER SERVICE DEPARTMENT IN ORDER TO AVOID PROCESSING DELAYS The assigned RMA number should then be marked on the outside
6. 20mA 20mA See test setup shown in Figure 1 Iterate steps 4 and 5 until no change is observed DD ACC 34 3 1 HP 245 AC FOR PULSE SCALING OPTION 1 An optional DIP switch is located on PCA 60 printed circuit card See Table B to determine required switch position and set into switch as shown in drawing ACC34 403 for required divided by N 2 For a required divide by 64 128 or 256 switch position 6 must be jumpered as shown drawing ACC34 403 TABLE A F MAX RANGE SELECT SWITCH POSITION 75 to 150 150 to 300 300 to 600 600 to 1200 1200 to 2400 TABLE B NOTE For divide by 64 128 or 256 switch position 6 is jumpered to appropriate location of PCA 60 printed circuit board 34 3 2 245 DESCRIPTION REDRAW ON AD 27 530305 m NOTES 1 USE TEST AMPLITUDE OF 100mVRMS OR LESS SINUSOIDAL WAVE FORM 2 REMOVE ALL OTHER INTERCONNECTIONS OTHER THAN THOSE SHOWN 3 OBSERVE CAUTION WHEN PERFORMING CALIBRATION FREQUENCY COUNTER DIGITAL MILLIAMP METER 2002298 INPUT SEE MODEL WHT 8 NUMBER MATERIAL CONTRACT JN RG 2 18 83 HOFFER FLOW CONTROLS INC CHER EUZABETH CITY NC 27909 FINISH JD TL mH E CALIBRATION SETUP FIGURE 1 AGE CODE DWG NO REV 3321700 0121 SIZE A a 07 87997
7. ACC 34 AC Powered Version MAG COIL FLOW RATE CONDITIONER FREQUENCY TO ANALOG VOLTAGE VEN 12 14 11111120 245 October 2006 HOFFER FLOW CONTROLS INC The Turbine Flowmeter Compan y 107 Kitty Hawk Lane P O Box 2145 Elizabeth City NC 27906 2145 800 628 4584 252 331 1997 FAX 252 331 2886 www hofferflow com E mail info hofferflow com Notice HOFFER FLOW CONTROLS INC MAKES NO WARRANTY OF ANY KIND WITH REGARD TO THIS MATERIAL INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE This manual has been provided as an aid in installing connecting calibrating operating and servicing this unit Every precaution for accuracy has been taken in the preparation of this manual however HOFFER FLOW CONTROLS INC neither assumes responsibility for any omissions or errors that may appear nor assumes liability for any damages that may result from the use of products in accordance with information contained in the manual HOFFER FLOW CONTROLS policy is to provide a user manual for each item supplied Therefore all applicable user manuals should be examined before attempting to install or otherwise connect a number of related subsystems During installation care must be taken to select the correct interconnecting wiring drawing The choice of an incorrect connection drawing may result in damage to the system and or one of the components Please
8. C the goods will be disposed of in HFC s discretion HFC does not warrant these goods to meet the requirements of any safety code of any state municipality or any other jurisdiction and purchaser assumes all risk and liability whatsoever resulting from the use thereof whether used singly or in combination with other machines or apparatus This warranty shall not apply to any HFC goods or parts thereof which have bee repaired outside HFC s factory or altered in any way or have been subject to misuse negligence or accident or have not been operated in accordance with HFC s printed instructions or have been operated under conditions more severe than or otherwise exceeding those set forth in the specifications for such goods THIS WARRANTY IS EXPRESSLY IN LIEU OF ALL OTHER WARRANTIES EXPRESSED OR IMPLIED INCLUDING ANY IMPLIED WARRANTLY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE HFC SHALL NOT BE LIABLE FOR ANY LOSS OR DAMAGE RESULTING DIRECTLY OR INDIRECTLY FROM THE USE OF LOSS OF USE OF THEGOODS WITHOUT LIMITING THE GENERALITY OF THE FOREGOING THIS EXCLUSION FROM LIABILITY EMBRACES THE PURCHASER 5 EXPENSES FOR DOWNTIME DAMAGES FOR WHICH THE PURCHASER MAY BE LIABLE TO OTHER PERSONS DAMAGES TO PROPERTY AND INJURY TO OR DEATH OF ANY PERSON HFC NEITHER ASSUMES NOR AUTHORIZES ANY PERSON TO ASSUME FOR IT ANY OTHER LIABILITY IN CONNECTION WITH THE SALE OR USE OF HFC S GOODS AND THERE ARE NO AGREEMENTS OR WARRANTIES COL
9. LATERAL TO OR AFFECTING THE AGREEMENT PURCHASER S SOLE AND EXCLUSIVE REMEDY IS THE REPAIR AND OR REPLACEMENT OF NONCONFORMING GOODS AS PROVIDED IN THE PRECEDING PARAGRAPHS HFC SHALL NOT BE LIABLE FOR ANY OTHER DAMAGES WHATSOEVER INCLUDING INDIRECT INCIDENTAL OR CONSEQUENTIAL DAMAGES Disclaimer Specifications are subject to change without notice Some pages are left intentionally blank HFC 9708 ACC 34 TALE OF CONTENTS SECTION I INTRODUCTION AND SPECIFICATIONS SECTION II INSTALLATION SECTION III CALIBRATION SECTION IV OPERATION SECTION V MAINTENANCE AND MAIN SCHEMATIC PAGE 2 1 3 1 4 1 5 1 HP 245 AC THIS PAGE INTENTIONALLY LEFT BLANK ACC 34 HP 245 AC SECTION I ACC 34 MAGNETIC PICKOFF CONDITIONER CURRENT CONVERTER The Model ACC 34 is a signal converter subsystem that provides an analog current output signal that is directly proportional to flow rate Several options are available to suit user requirements An auxiliary pulse output is also provided These features combine to form an interface between a flow transducer and a host system The input signal conditioning circuitry is designed to accept the low level flowmeter signal while providing rejection of unwanted noise and spurious signal A signal threshold control is provided which allows the user to set the input sensitivity above the ambient noise level thereby eliminating any false signal on the output Several output puls
10. OOF WITH WATER TIGHT RING MEETS CLASS I GROUP D ADALET CASE XJS WITH FLAT COVER STOCK 200 0698 CLASS II GROUPS E F amp G CLASS NOTE INSERT X INMODEL NUMBER FOR EVERY OPTION NOT SPECIFIED ACC 34 1 3 HP 245 AC THIS PAGE INTENTIONALLY LEFT BLANK ACC 34 1 4 HP 245 AC GENERAL SECTION I FLOWMETER INSTALLATION Proper application of the turbine flowmeter requires a suitable piping installation in order to achieve accurate and reliable operation The piping configuration immediately preceding and following the flowmeter is termed the meter run Refer to the manufacturer s outline and installation instructions when installing the flowmeter and meter run RELATIVE METER RUN BYPASS RUN STRAINER CAVITATION ACC 34 The performance of the turbine flowmeter is affected by the fluid swirl and non uniform velocity profiles The following recommendation will reduce such flow irregularities It is advisable not to locate the meter run immediately downstream of pumps partially opened valves bends or other similar piping configurations In addition the area surrounding the flowmeter should be free of sources of electrical noise such as motors solenoids transformers and power lines which may be coupled to the pickoff device The metering section should not be subjected to excessive vibration or shock Such a condition may result in a mechanically induced output signal from the pickoff
11. RVE CAUTION WHEN PERFORMING CALIBRATION FREQUENCY COUNTER DIGITAL MILLIAMP METER 2002298 INPUT SEE MODEL WHT 8 NUMBER MATERIAL CONTRACT JN RG 2 18 83 HOFFER FLOW CONTROLS INC CHER EUZABETH CITY NC 27909 FINISH JD TL mH E CALIBRATION SETUP FIGURE 1 AGE CODE DWG NO REV 3321700 0121 SIZE A REVISIONS REV DESCRIPTION DATE APP NOTES ENCLOSURE MEETS CLASSI GROUPS C amp D CLASS Il GROUPS E F amp G NEMA 7 amp 9 4 7 8 3 3 4 DT gt 3 3 4 5 7 8 REMOVABLE COVER AA 5 5 8 1 NPT TYP 2 PLACES MERLO DRAWING DATE CHECK H HOFFER FLOW CONTROLS INC CW ELIZABETH CITY NC 27909 FINISH ENCLOSURE x EXPLOSION PROOF CONFIDENTIAL PROPERTY OF HOFFERIUNLESS OTHERWISE SPECIFIED STYLE 4H FLOW CONTROLS INC HFC NOT DIMENSIONS ARE IN INCHES SIZE FSCM NO DWG NO REV A332 500 0020 TO DISCLOSED TO OTHERS TOLERANCES OTHER THAN RAW PA 00 1 REPRODUCED OR USED FOR ANY MATERIAL SHALL HELD OTHER PURPOSE EXCEPT AS 5 FOLLOWS AUTHORIZED IN WRITING BY HFC USED ON Js BE RERED N Da 5 PLACE 005 LEN ORDER OR OTHER FRACTIONAL 31 64 APPLICATION PURPOSE FOR WHICH LENT ANGULAR
12. d into an analog voltage that is proportional to volumetric flow rate The output amplifier is a voltage to current amplifier It offers zero and span available in a standard process range of 4 20mA ACC 34 4 1 HP 245 AC THIS PAGE INTENTIONALLY LEFT BLANK ACC 34 4 2 HP 245 AC SECTION V MAINTENANCE GENERAL Hoffer Flow Controls Flow Measurement Systems are constructed to give a long service life in the targeted measuring field and service environment However problems do occur from time to time and the following points should be considered for preventive maintenance and repairs The bearing type used in the flowmeter chosen to give compromise between long life chemical resistance ease of maintenance and performance A preventive maintenance schedule should be established to determine the amount of wear which has occurred since last overhaul See user s manual for flowmeter for further instructions A spare parts list has been provided which at the discretion of the user may be user stocked Consult with the manufacturer is an abridged spare parts list is sought The recommended spare parts list may be found following this section and in the user s manual for the flowmeter In case the flow measurement system malfunctions or becomes inoperative a troubleshooting procedure is enclosed Factory consultation is available to assist in diagnosing problems In addition factory repair parts and service are available for individua
13. device In general the meter run should be chosen to have the same inner diameter as the meter bore A minimum of 10 pipe diameters of straight pipe upstream and 5 pipe diameters downstream are required Where this optimum line configuration can not be implemented it is advisable to install a flow straightener properly ponon upstream of the flowmeter Orientation is not a critical factor however orizontal is preferred orientation A properly sized bypass run with suitable blocking valves may be equipped where an interruption in fluid flow for turbine meters servicing cannot be tolerated A strainer filter and or air eliminator is recommended to reduce the potential of fouling or damage See table for recommended mesh size On initial startup of a line it is advisable to install a spool piece purging the line to eliminate damaging the flowmeter due to flux tape solder welds or other contaminates carried along by the fluid stream Cavitation causes measurement inaccuracies in turbine flowmeters and should be avoided by suitable line and operating configurations Whenever the pressure within a pes instantaneously falls below the equilibrium vapor pressure of the fluid a portion of the fluid vaporizes and forms bubbles in the pipeline This is termed cavitation Cavitation is eliminated by maintaining adequate back pressure on the flowmeter A downstream valve that provides the necessary back pressure is one means for preventing cavi
14. e configurations are provided which offer flexibility in the interface required by the host system The output is available in the form of CMOS TTL compatible pulse or in the form of an open collector SPECIFICATIONS INPUT ANALOG OUTPUT Input protected RF and band pass filtered adjustable trigger level Input Impedance 40 Kilo ohm nominal Trigger Sensitivity 10 millivolt RMS minimum 10 Hz to 1000 Hz Over Voltage 120 volts RMS absolute maximum Compatible with magnetic pickoffs Range 4 to 20 mA Controls Non interacting zero and span adjustments Accuracy 0 1 F S 200 ppm EC Maximum Impedance 325 ohms F S Frequency Range 75 Hz to 2500 Hz DIP SWITCH SELECTABLE PULSE SCALING CAPABILITY OPTIONAL ACC 34 2 4 8 16 32 64 128 and 256 1 1 HP 245 AC PULSE OUTPUT POWER REQUIREMENTS OPTIONAL TEMPERATURE ENCLOSURE OPTIONS TTL CMOS COMPATIBLE OPTION LOGIC 1 2 4V at 800mA LOGIC 0 0 4V maximum at 100mA OPEN COLLECTOR OPTION TYPE VMOS 2N6660 V Max Abs 60 VDC I Max Abs 100 mA AC OPTION 5Vp p Square Wave 115 VAC 50 60 Hz 15 35 VDC OE to 70EC Standard Standard enclosure Style 2 Case See outline drawing Explosion Proof Enclosure Explosion Proof Enclosure with O ring seal NEMA 4 Enclosure CONTROLS AND ADJUSTMENTS FUSE SENSITIVITY RANGE SPAN ZERO SCALING FACTOR ACC 34 A circuit protection device located inside
15. ended Ground shield on one end only Use some precautions as described for flowmeter input signal ACC 34 2 2 HP 245 AC REVISIONS 1 FACTORY RECOMMENDS 10 PIPE DIA DESCRIPTION DATE APP UPSTREAM AND 5 PIPE DIA DOWNSTREAM REDRAWN 1 31 92 OF SAME SIZE PIPE AS FLOWMETER A ADDED NOTE 2 CHG D MESH SIZE 3 17 9 FLOW STRAIGHTENER IS RECOMMENDED C DRAWING NO WAS INSTL 104 950907 7 2 THIS IS NOT POSSIBLE OR FOR CUSTODY Ka 950907 TRANSFER APPLICATIONS BYPASS RUN V1 2 BLOCKING VALVE 5 STRAINER FS FLOW STRAIGHTENER TURBINE FLOWMETER BYPASS VALVE V REPLACES INSTL 104 DRAWN D OREO HOFFER FLOW CONTROLS INC JD 1 51 92 ELIZABETH CITY NC 27909 TYPICAL PROJ ENG TURBINE INSTALLATION SIZE CODE DWG NO REV 3321500 01 FRACTIONAL 31 64 mur 102 OF 1 dRAWINGS 500 50001941 DWG FINISH FLOW CONTROLS INC re NOT DIMENSIONS ARE IN INCHES TO BE DISCLOSED TO OTHERS NEXT ASSY USED ON Be RTURED 0 CAND 00 APPLICATION COMPLETION OF ORDER OR OTHER PURPOSE FOR WHICH LENT 2 PLACE DECIMAL 01 PLACE DECIMAL 005 DESCRIPTION REDRAW ON AD 27 530305 m NOTES 1 USE TEST AMPLITUDE OF 100mVRMS OR LESS SINUSOIDAL WAVE FORM 2 REMOVE ALL OTHER INTERCONNECTIONS OTHER THAN THOSE SHOWN 3 OBSE
16. eted install the flowmeter and connect cabling to pickup coil If false counting action occurs turn sensitivity control clockwise OPERATION The pulse output and analog output commence with flow through the flowmeter For the analog output the span is then established by either the factory calibration or field calibration The range is 4 20mA DC into a maximum of 325 ohms of loop resistance PRINCIPLE OF OPERATION A simplified block diagram of the ACC34 Frequency Current Flow Converter Subsystem is given on drawing ACC34 601 Key functional blocks as well as information flow are designated The basic operation of the system is as follows The frequency signal from the flowmeter is connected to the ACC34 with a twisted pair shielded cable The signal enters through the SENSITIVITY control which is used to reject unwanted noise by raising the trigger threshold above the background noise present The low level flowmeter signal is then passed through a special conditioning chain where it is amplified and shaped into a train of digital pulses whose frequency is related to the volume flow rate ANALOG OUTPUT The signal entering the frequency to analog converter is passed through a combination of divide by N and DIP switch MATRIX The QN output is chosen whose pulse rate is between 75 and 150 Hz at the maximum flow rate to be measured This scaled pulse rate is fed into a precision monostable circuit The output of the monostable is then filtere
17. ls who wish to utilize this service A complete set of schematic diagrams for all printed cards are available from Hoffer Flow Controls for users who wish their own personnel to service the measuring system NOTE All printed circuit cards are warranted for one year after date of sale All printed circuit cards may be factory repaired at a nominal fee for parts and labor after warrantee period TROUBLESHOOTING AND MAINTENANCE INTRODUCTION In case of an inoperable or malfunctioning system the following procedures can be used to isolate the faulty wiring printed circuit boards and or alternate causes The majority of repairs can be made in the field thereby reducing the time a unit is out of service A recommended spare parts list is given immediately following the troubleshooting portion of this manual The necessary documentation is contained within this manuals with the exception of the calibration data sheet for the turbine flowmeter This calibration is supplied separately Factory consultation is available to assist in diagnosing problems Note that in some cases factory repairs can be provided Failure conditions are listed and the possible corrective actions given to eliminate the observed problem ACC 34 5 1 HP 245 AC GENERAL INSPECTION TO DETERMINE IF UNIT IS OPERATING PROPERLY Proper operation of the ACC34 can be assumed when with power applied to the unit 1 The pulse output produces a pulse train of the desired ampli
18. nd or replacement of nonconforming goods as provided in the following paragraphs In the event Purchaser believes the goods are defective the goods must be returned to HFC transportation prepaid by Purchaser within twelve 12 months after delivery of goods or eighteen 18 months for goods delivered outside the continental United States for inspection by HFC If HFC s inspection determines that the workmanship or materials are defective the goods will be either repaired or replaced at HFC s sole determination free of additional charge and the goods will be returned transportation paid by HFC using the lowest cost transportation available Prior to returning the goods to HFC Purchaser must obtain a Returned Material Authorization RMA Number from HFC s Customer Service Department within 30 days after discovery of a purported breach of warranty but no later than the warranty period otherwise such claims shall be deemed waived See the Return Requests Inquiries Section of this manual If HFC s inspection reveals the goods are free of defects in material and workmanship or such inspection reveals the goods were improperly used improperly installed and or improperly selected for service intended HFC will notify the purchaser in writing and will deliver the goods back to purchaser upon i receipt of Purchaser s written instructions and ii the cost of transportation If Purchaser does not respond within 30 days after notice from HF
19. of the return package and on any correspondence FOR WARRANTY RETURNS please have the following information available BEFORE contacting FOR NON WARRANTY REPAIRS CALIBRATIONS consult HOFFER FLOW HOFFER FLOW CONTROLS CONTROLS for current repair calibration charges Have the following information available BEFORE 1 P O number under which the product was contacting HOFFER FLOW CONTROLS PURCHASED 2 Model and serial number of the product under 1 P O number to cover the COST of the warranty and repair calibration 3 Repair instructions and or specific problems relative 2 Model and serial number of the product and to the product 3 Repair instructions and or specific problems relative HFC 9708 to the product LIMITED WARRANTY HOFFER FLOW CONTROLS INC HFC warrants HFC s products goods described in the specifications incorporated in this manual to be free from defects in material and workmanship under normal use and service but only if such goods have been properly selected for the service intended properly installed and properly operated and maintained This warranty shall extend for a period of 1 year from the date of delivery to the original purchaser or eighteen 18 months if the delivery to the original purchaser occurred outside the continental United States This warranty is extended only to the original purchaser Purchaser Purchaser s sole and exclusive remedy is the repair a
20. tation in the metering run Control valves should be located downstream if possible Some installations may also make use of a vapor eliminator upstream of the flowmeter The minimum required back pressure may be estimated using the following equation Min Back Pressure 1 25 X Vapor Pressure 2X Pressure Drop 2 1 HP 245 AC INSTALLATION WIRING LAYOUT FOR INTERCONNECTIONS USING MCP PICKUP In considering the interconnections between the flowmeter and the flow measurement system some attention must be given to anticipated noise sources and to the coupling of these noise sources to the interconnecting wiring Noise signals may be coupled inductively or capacitively into the wiring between the flowmeter and the electronic measuring systems In general utilizing a shielded twisted pair for the interconnection greatly reduces this coupling The shield should be grounded on one end of the cable only In general grounding only on the electronic measuring system is best However even with po er interconnecting cabling Crosstalk with other signal lines or power lines may still occur and should be avoided Physical isolation in the manner in which the wiring is run reduces the chance of potential problems It is common to transmit the low level output signal form the flowmeter several hundred feet through a shielded twisted pair instrument cable Where a noisy environment is suspect it is recommende that a preamplifier be installed on or near
21. the flowmeter to the electronic measuring system Suitable accessory models are available from manufacturer INSTALLATION ACC 34 AC POWERED VERSION The Model ACC 34 should be convenient location which maintains access to the unit should repairs or readjustment be required Refer to outline and installation drawing for the appropriate case type to be installed Drill appropriate mounting holes as required Refer to wiring installation drawing for appropriate terminals for interconnections Connections to the terminal block should be carefully dressed to avoid having bare wires extend the screw clamp on the terminal block This is particularly important for units mounted within the explosion proof enclosure Wires should be neatly dressed near the bottom of the enclosure to assure wiring will not become fouled when the cover is installed Connect two conductor shielded cable from the flowmeter Connect shield to ACC 34 only Line power connection should be made through a circuit breaker so that power can be turned off while servicing accessory model Power is 117 AC 10 an earth ground connection is also required Connect pulse output if used several output pulse waveforms are available factory equipped Wire to appropriate terminal for waveform desired and specified If the analog output has been equipped connect wiring to appropriate terminals and load A shielded g outp 4 pp 5 PP twisted pair wire is recomm
22. tude when flow through the flow transducer occurs 2 The analog output produces a current output signal of 4 20mA with a span corresponding to that established by the calibration procedure OBSERVED CONDITION A NO PULSE OUTPUT B PULSING OUTPUT WITH NO FLOW C ANALOG OUTPUT MALFUNCTION CORRECTIVE ACTION 1 N SON Be Inspect terminal strip wiring for conformity to the installation instructions and for acceptable workmanship Verify correct fuse is good with an ohm meter See dwg ACC34 403 Determine if flowmeter rotor is fouled Defective pickup coil Replace Defective cable Replace Defective ACC34 Repair or replace Sensitivity potentiometer turned fully clockwise unit will not function properly Defective pickup coil Replace Defective cable Replace Defective ACC34 Repair or replace Improper wiring terminations Correct wiring ACC34 improperly calibrated Recalibrate Defective circuitry within the ACC34 Factory repair ACC34 NOTE Refer to flowmeter user s manual for repair instructions for the turbine flowmeter MODEL ACC34 FREQUENCY CURRENT FLOW CONVERTER SUBSYSTEM TABLE 1 RECOMMENDED SPARE PARTS LIST PART NUMBER DESCRIPTION QTY 1 20 AMP FUSE POWER SUPPLY 1 BOX ACC34 XX CONDITIONER CON VERTER 1 PC XX XX COIL 1 NOTE Additional spare parts may be recommended for the turbine flowmeter See user s manual for turbine flowmeter for details ACC 34 5 2
23. wmeter s calibration sheet From the calibration constant or K Factor listed on the data sheet for the flowmeter obtain the frequency corresponding to GPM MAX using Equation 1 and designate this frequency F MAX Equation 1 Kava X GPM max 60 F MAX The analog output of the ACC 34 may be calibrated with the aid of an external oscillator used in conjunction with a frequency counter The external oscillator is used to supply a test frequency In this method the external oscillator is connected to the signal input terminals as shown in Figure 1 The oscillator s output frequency is set to equal as indicated on the frequency counter 1 The course range adjustment is accomplished by selecting a switch position on a DIP switch located on the PCA 61 printed circuit card See Table A to determine required switch position and set into switch as shown on drawing ACC 34 403 for anticipated NOTE Input power should be removed during this step It is necessary to open the cover of the enclosure by removing two screws and lifting the cover Two printed circuit cards are attached The RANGE Dip Switch may be programmed with a pen Connect a digital milliampmeter or equivalent across the current output terminals Adjust ZERO control for desired zero current 1 6 4mA Turn SPAN POT fully CCW until detent is felt or 25 turns Inject the test frequency equal to Fmax while adjusting SPAN for current equal to
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