ACC-22B - Hoffer Flow Controls, Inc
Contents
1. ALL DIMENSIONS ARE IN INCHES ACC 22B Page 5 of 19 HP 206 Figure 1 5 Explosion Proof Case Style 4B 7 OPTIONAL O RING ALL DIMENSIONS ARE IN INCHE 1 6 SHIPPING AND HANDLING CAUTION The ACC22B is a static sensitive devise and standard practice for static sensitive parts should be observed In the event of malfunctioning equipment the following guidelines should be observed for the preparation and shipment of the equipment Failure to do so may result in the material reaching its destination damaged The electronic unit due to its STATIC SENSITIVE nature should be wrapped in a material conforming to MIL B 81705 Type II and packaged in a heat sealable bag conforming to MIL P 81997 These steps are necessary to protect the equipment from electrostatic charge s that may occur during handling The package should then be marked with a sensitive electronic device caution label conforming to MIL STD 129 appendix C The equipment should then be wrapped in cushioning material and placed into a close fitting box conforming to PPP B 636 Domestic class The exterior shipping container should be marked with a sensitive electronic device caution label conforming to MIL STD 129 appendix C Clearly mark the factory provided RMA number on all paperwork and shipping packaging ACC 22B Page2. PCA 112 TEST FREQ ADJ TEST FREQ PCA 115 PULSE OUTPUT TEST POINT SCALER 120 Hz c PCA 113 OR PCA 114 ACC 22B Page 14 of 19 HP 206 4 44 PROCEDURE Begin by determining the offset frequency of the mini flowmeter This is supplied on the calibration sheet term this F OS The mini flow linearizer may be calibrated with the internal TEST frequency or an external oscillator used in conjunction with a frequency counter The internal test signal when jumpered to the input terminal injects an internally generated frequency When using this feature F TEST is equal to 120 Hz The expected output frequency can be calculated by the following equation Four 78 Fog Where FOUT is the expected output frequency FTEST is the test frequency used FOS is the offset frequency Connect frequency counter to the offset frequency test point and observe that the frequency equals 10 X F OS Connect frequency counter to the output of the unit and with an injected TEST frequency verify that the output frequency equals equation 1 4 4 4 CALIBRATION FOR LIQUID SERVICE FLOWMETERS The ACC22B may be calibrated with an internal TEST frequency or an external oscillator used in conjunction with a frequency counter The TEST frequency is jumpered to the input injects an internally generated frequency into the unit When using this feature F TEST is
3. ACC 22B Page 12 of 19 HP 206 4 CALIBRATION PROCEDURE 4 1 INTRODUCTION In general all flow measurement systems supplied by Hoffer Flow Controls have been factory calibrated as specified by the user at the time of purchase systems which under went such a factory calibration have a calibration card attached prior to shipment This card contains the flow rate offset frequency and low flow set point Field calibration is only required when a change has occurred Such a change may be due to repair replacement or recalibration of the flowmeter 4 2 REQUIRED TEST EQUIPMENT In order to perform field calibration and troubleshoot the ACC22B the following suggested equipment list is provided Eie m s censa 1000 Adjustment Tool 43 CONTROLS AND ADJUSTMENTS FUSE A circuit protection device located internally for 110 220 VAC input power only Fuse is a 1 4 Amp SENSITIVITY A twenty turn control used to set the threshold sensitivity level above the ambient noise pickup SPAN A twenty turn adjustment which is used to set current voltage output to the desired span corresponding to the equivalent flow range i e 20 mA or 5 VDC corresponding to 0 100 GPM ZERO A twenty turn adjustment which is used to set the current voltage output signal to the desired zero value i e 4mA or OVDC at zero GPM RANGE SELECT A dual in line DIP switch which is located on the PCA 112 board which is used to program
4. 1 2 PERFORMANCE CHARACTERISTICS INPUT POWER e 15 35 VDC or 110 220 VAC 50 60 Hz available INPUT e Input protected RF and band pass filtered adjustable trigger level e Input Impedance 40 kilo ohm nominal Trigger Sensitivity 10 millivolt RMS minimum 10 Hz to 1000 Hz Over voltage 120 volts RMS absolute max METHOD OF LINEARIZATION e Frequency injection of offset frequency with post scaling and low flow alarm OFFSET FREQUENCY e 00 0 to 150 0 Hz THERMAL STABILITY e 200 PPM C ACC 22B Page 1 of 19 HP 206 LOW FLOW ADJUSTMENT e 20 to 200 Hz based on comparison with input flowmeter frequency CURRENT OUTPUT OPTION Accuracy 0 05 of full scale Temperature drift 200 PPM C Available range 4 to 20 Ma Output suitable for driving floating or grounded loads e Maximum loop impedance 375 ohms Response time 0 5 seconds for 10 to 9096 VOLTAGE OUTPUT OPTION Accuracy 0 05 of full scale Temperature drift 200 PPM C e Available range 0 to 5 vdc e Impedance less than 10 ohms Response time 0 5 seconds for 10 to 9096 PULSE OUTPUTS e Open Collector V mos transistor 2N6660 Maximum OFF state voltage 60 VDC Maximum ON current 1 0 amps e TTL CMOS fanout of 10 TTL CMOS loads e A C capacity coupled square wave 5 Vp p ENVIRONMENTAL e OPERATING 20 TO 85 STORAGE 65 TO 150 C ENCLOSURES General purpose standard case
5. OBSERVED CONDITION CORRECTIVE ACTION e UNIT REPEATEDLY BLOWS FUSES INSPECT TERMINAL STRIP WIRING FOR CONFORMITY TO THE INSTALLATION INSTRUCTIONS AND FOR ACCEPTABLE WORKMANSHIP VERIFY CORRECT FUSE SIZE REPLACE PCA 112 REPLACE PCA 115 REPLACE PCA 113 OR PCA 114 NOTE IF UNIT CONTINUES TO BLOW FUSES IT IS ADVISABLE TO RETURN IT TO THE FACTORY THIS DEFECT IS DIFFICULT TO DIAGNOSE IN AN ASSEMBLED SYSTEM UNIT GIVES NO PULSE OUTPUT WITH TURN SENSITIVITY POTENTIOMETER FLOW PRESENT CLOCKWISE REPLACE PICKUP COIL AND OR INTERCONNECTING WIRING REPLACE PCA 113 OR PCA 114 REPLACE PCA 115 REPLACE PCA 112 ACC 22B Page 18 of 19 HP 206 OBSERVED CONDITION CORRECTIVE ACTION e UNIT GIVES PULSE OUTPUT WITH NO e NOISE PICKUP TURN SENSITIVITY FLOW PRESENT ADJUST COUNTER CLOCKWISE UNTIL CORRECT ZERO FLOW INDICATION IS OBTAINED REPLACE PICKUP COIL REPLACE PCA 115 REPLACE PCA 113 OR PCA 114 e UNIT DOES NOT FUNCTION PCA 115 HAS INCORRECT OFFSET FREQUENCY SETTING REPLACE PCA 115 FLOWMETER USED BELOW OR ABOVE NORMAL RANGE OBTAIN CORRECT FLOWMETER e ANALOG OUTPUT REPLACE PCA 112 e ANALOG OUTPUT WITH NO FLOW TURN SENSITIVITY SLOWLY CCW REPLACE PCA 112 NOTE FULLY CCW WILL MAKE UNIT INOPERATIVE ACC 22B Page 19 of 19 HP 206
6. NEMA 4 Explosion proof ACC 22B Page 2 of 19 HP 206 1 3 ORDERING INFORMATION MODEL ACC22B B C D F PULSE INPUT TYPE PULSE OUTPUT ANALOG OUTPUT INPUT POWER PULSE SCALING ENCLOSURE STYLE PULSE INPUT TYPE MODEL 22 CH OPTION 1 MAGNETIC PICKUP Q MC3P PULSE OUTPUT MODELACC2B 5 X C OPTION 1 OPEN COLLECTOR Q TTL CMOS 3 AC SQUARE WAVE 4 HIGH VOLTAGE PULSE 5 0 10 V SQUARE WAVE ANALOG OUTPUT MODEL ACC22B COC OPTION 3 0 5 VDC 7 4 20 MA INPUT POWER MODEL ACC22B O5 M OPTION A 115 VAC 50 60 HZ Q 220 VAC 50 60 HZ WHEN MCP COIL AND 4 20 MA IS REQUIRED EQUIP ACC22B FOR DC POWER TO BE POWERED BY ACC39B D 15 35 VDC PULSE SCALING SELECTED BY FACTORY DEPENDENT UPON MINI FLOWMETER MODEL 228 CE OPTION PS DIP SWITCH SELECTABLE DIVIDE BY 2 4 8 16 32 64 128 ENCLOSURE STYLE MODEL 22 9C STYLE 3 CASE GENERAL PURPOSE HEIGHT 3 22 4H O STYLE 4 CASE EXPLOSION PROOF 5 70 HIGH WITH WATER TIGHT O RING MEETS CLASS I GROUP amp D ADALET XJSD CASE WITH DOME COVER STOCK 4200 0760 CLASS II GROUPS E F amp G NOTE INSERT X INMODEL NUMBER FOR EVERY OPTION NOT SPECIFIED ACC 22B Page 3 of 19 HP 206 14 WARRANTY 2222222222 1 5 Hoffer Flow Controls warrants that all equipment will be free from defects
7. 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 1 receipt of Purchaser s written instructions and ii the cost of transportation If Purchaser does not respond within 30 days after notice from HFC the goods will be disposed of in HFC s discretion HFC does not warrant these goods to meet the requirements
8. 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 ORIMPLIED 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 S 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 COLLATERAL TO OR AFFECTING THE AGREEMENT PURCHASER S SOLE AND EXCLUSIVE REMEDY IS THE REPAIR AND OR REPLACEMENT OF NONC
9. output or both pulse and analog outputs For the pulse output connect to terminal block TB1 terminal 6 for pulse signal and terminal 7 for pulse common For the analog output connect to terminal block TB1 terminal 4 for output signal and terminal 5 for signal common ACC 22B Page 7 of 19 HP 206 ACC 22B Figure 2 1 Installation Wiring For Magnet Pickup 110 220 VAC N TES L INSTALL A JUM TERMINAL 8 TO TERMINAL 1 2 UNIT CTC LINE EARTH t Figure 2 2 Installation Wiring For Magnet Pickup 15 to 35 VDC TALL A JUMPER FROM OUTPUT PULSE OUTPUT Page 8 of 19 HP 206 Figure 2 3 Installation Wiring With MCP Coil 110 220 VAC ANA OUTPUT PULSE OUTPUT COMMON F TEST Figure 2 4 Installation Wiring With MCP Coil 15 to 35 VDC WITH AN INTERNAL O INJECT THIS ALL A JUMPER FROM ERMINAL 1 COMMON F TEST ACC 22B Page 9 of 19 HP 206 THIS PAGE LEFT INTENTIONALLY ACC 22B Page 10 of 19 HP 206 3 FUNCTIONAL DESCRIPTION 3 1 PRINCIPLE OF OPERATION MAGNETIC PICKUP INPUT TYPE A simplified block of the ACC22B Mini Flow Linearizer is given on drawing Figure 3 1 The basic operation of the system is as follows The frequency signal from the flowmeter is connected to the ACC22B with a twisted pair shielded cable The signal enters through the Sensitivity control which is used to reject unwanted noise by raising the trig
10. 2B should be placed in a convenient location which maintains access to the unit should repairs or readjustments be required Refer to installation Figure 2 1 thru 2 4 for appropriate configuration and the appropriate terminals for interconnecting Connections to the terminal block should be carefully dressed to avoid having bare wires extend pass the screw clamp on the terminal block Wires should be neatly dressed near the bottom of the enclosure to prevent problems when the cover is installed Connect two conductor shielded cable from the flowmeter to terminal block TB1 terminals 1 and 2 Connect the shield to terminal block TB1 terminal 3 If the unitis configured for 110 220 VAC power refer to model number for power option ordered connect the power wiring to terminal block TB2 Connect to terminal A line black to terminal B neutral white and to terminal C earth green The AC line power should be and instrument grade line whose various loads do not contain solenoids values or other similar transient producing loads which might adversely affect the operation of the system If the unit is configured for 15 to 35 VDC power refer to model number for power option ordered connect the power wiring to terminal block TB2 Connect to terminal A positive voltage supply to terminal B connect the negative voltage supply and to terminal C connect the earth or chassis lead The output signal from the ACC22B may be either a pulse output or analog
11. 6 of 19 HP 206 2 INSTALLATION 2 1 INSTALLATION WIRING LAYOUT FOR INTERCONNECTIONS Inconsidering 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 proper interconnecting cabling cross talk 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 from a magnetic type pickup coil several hundred feet through a shielded twisted pair instrument cable In the event that a Modulated Carrier Pickup MCP the signal conditioner should be located no more than 100 feet away In either case where a noisy environment is suspected it is recommended that a signal conditioner be installed on or near the flowmeter to the electronic measuring system Suitable accessory models are available from manufacturer 2 2 INSTALLATION OF THE ACC22B The Model ACC2
12. ACC 22B SIGNAL CONDITIONER USER S MANUAL HP 206 January 2011 PERFECTING MEASUREMENT H HOFFER FLOW CONTROLS INC 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 review the complete model of each item to be connected and locate the appropriate manual s
13. ONFORMING 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 TABLE OF CONTENTS PREFACE gyn aii cute esca ecc abide tte tb sce ei i I INTRODUCTION Ub He OE Ee ag uu aad beet a pec ae RC ala ORC ERE 1 1 1 INTRODUCTION i lia Guha oa RE ad se ai ERR A d RE To dade a i A 1 1 2 PERFORMANCE CHARACTERISTICS e e 1 1 3 ORDERINGINFORMATION e he 3 L4 WARRANTY Baa a C tue ntu ep redet eques 4 15 ENCBOSUREDETAIL mw O O FQ UNI NEG uu exer PIN 4 1 6 SHIPPING AND HANDLING hh I Hh hh 6 2 INSTALLATION stia ped e an Pe ML D lea 7 2 1 INSTALLATION WIRING LAYOUT FOR INTERCONNECTIONS 7 2 2 INSTALLATION OF THE ACC22B mh n 7 3 jJ NCLIIONAL DESCRIPTION opisati eh dare MEU bate bee Sale E 11 3 1 PRINCIPLE OF OPERATION MAGNETIC PICKUP INPUT TYPE 11 3 2 PRINCIPLE OF OPERATION MCP PICKUP INPUT TYPE 11 4 CALIBRATION PROCEDURE ke A abe Ee whe ADR RR CR RU e o EOS RUR CR ER ake 13 4 INTRODUCTION teu cbe et c bed douces
14. Turn the SPAN control fully counter clockwise until slippage is felt or 25 turns Table 4 1 Range Select F MAX RANGE SELECT SWITCH POSITION 300 to 600 600 to 1200 1200 to 2400 2400 to 4800 4 4 2 FOR CURRENT OUTPUT OPTIONS ONLY 4 4 3 Connect a digital milliampmeter or equivalent across the current output terminals Adjust Zero control for desired Zero current i e 4mA Inject the test frequency while adjusting SPAN for current equal to SET SPAN Iterate above steps until no change is observed FOR VOLTAGE OUTPUT OPTION ONLY Connect a digital voltmeter across the voltage output terminals Adjust Zero control for desired Zero current i e Ovolts Inject the test frequency while adjusting SPAN for voltage equal to SET SPAN Iterate above steps until no change is observed ACC 22B Page 16 of 19 HP 206 5 MAINTENANCE 5 1 INTRODUCTION 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 A spare Parts List has been provided which at the discretion of the user may be user stocked Consult with the manufacturer if an abridged spare parts list is sought The recommended spare parts list may be found following this section and in the users manual for the flowmet
15. 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 of the return package and on any correspondence FOR WARRANTY RETURNS please have the follow
16. apacitor coupled AC output which is suitable for driving other signal conditioners indicators or controllers which require an AC signal input The power supply takes the available input power either 115 220 VAC or DC voltage depending on Model option selected and provides the power required by the various circuitry A stable oscillator is provided which generates a 120 Hz test signal which may be used to perform tests on the ACC22B 3 2 PRINCIPLE OF OPERATION MCP PICKUP INPUT TYPE A simplified block diagram of Modulated Carrier Conditioner Converter is given Figure 3 2 Key functional blocks as well as information flow are designated The basic operation of the system is as follows The MCP on the turbine flowmeter is connected to the Model ACC22B with a shielded twisted pair signal cable The MCP pickup coil forms part of an oscillator circuit and is excited by the ACC22B Motion of the turbine rotor modulates the oscillator output A demodulator converts the AM signal to a single at a frequency determined by the rotor speed The low level demodulated signal is then passed through a signal conditioning chain where it is filtered amplified and shaped into a train of digital pulses whose frequency is related to the volume flow rate and where each pulse represents a discrete volume of fluid The digital pulse train is then passed through the linearizer where the offset frequency signal is injected into it For flow rates within the range of t
17. c v rd 13 4 2 REQUIRED TEST EQUIPMENT m mh eree 13 4 3 CONTROLS AND ADJUSTMENTS c m he 13 4 4 PROCEDURE Seb Ek eun uer RACIO OR IE QU GP FEES PUES 15 4 4 1 CALIBRATION FOR LIQUID SERVICE FLOWMETERS 15 4 4 2 FOR CURRENT OUTPUT OPTIONS ONLY sseeeeeee ee 16 4 4 3 FOR VOLTAGE OUTPUT OPTION ONLY I 16 S MAINTENANCE n VERIS let a aE 21 SU INTRODUCTION wien e Tau DA CIC Bev bpd ee Ra Pai AS 21 5 2 TROUBLE SHOOTING AND MAINTENANCE eee 21 LIST OF FIGURES Figure 1 1 Ordering Information re eR CR RC RO RR CLR RU RORIS BUR CE C aa as 3 Figure 1 2 General Purpose Case Style 2 cece n 4 Figure 1 3 Explosion Proof Case Style 4H and 4 5 Figure 1 4 NEMA 4 Case Style 5 suae pb eR EY GERE 5 Figure 1 5 Explosion Proof Case Style4B 6 Figure 2 1 Installation Wiring For Magnet Pickup 110 220 VAC 0 0 0 8 Figure 2 2 Installation Wiring For Magnet Pickup 15 to 35 VDC 8 Figure 2 3 Installation Wiring With MCP Coil 110 220 ne 9 Figure 2 4 Installation Wiring With MCP Coil 15 to 35 VDC eee 9 Figure 4 1 Control and Adjustment Detail I 14 ACC 22B HP 206 THIS PAGE LEFT INTENTIONALLY ACC 22B HP 206 PREFACE This manual provides all the necessary
18. equal to 120 Hz and is used in the following equations An external oscillator may be used to supply a test frequency In this method the external oscillator is connected to the signal input terminals The oscillator s output frequency is set to equal F MAX as indicated on the frequency counter For this approach use F MAX in the following equations for F TEST Regardless of the method used begin by calculating the following setpoints indicated by Equation 1 through Equation 3 Use the frequency F TEST depending on calibration method chosen above Equation 1 F MAX K FACTOR X R MAX F OS 60 Equation 2 SET ZERO SET TO NO FLOW CONDITION i e 4mA 5mA or OV Equation 3 SET SPAN F TEST F OS X SPAN F OS ZERO ACC 22B Page 15 of 19 HP 206 Where F TEST is test frequency used F OS is offset frequency F MAX is the flowmeter output frequency at R MAX when at the reference condition at which the relation with FIMAX was defined K Factor is in units of readout i e PULSE GAL R MAX is the maximum flowrate of the flowrate of the flowmeter SPAN is varying component of analog output i e 16mA for 4 to 20mA output OV for 0 to 5V output The Range Adjustment is accomplished by selecting a switch position on a DIP switch located on the PCA 112 printed circuit card depending upon the model See Table 4 1 to determine required switch position select switch position as shown on drawing ACC22B
19. er In case the flow measurement system malfunctions or becomes inoperative a trouble shooting procedure is enclosed Factory consultation is available to assist in diagnosing problems In addition factory repair parts and service are available for individuals who wish to utilize this service 5 2 TROUBLE SHOOTING AND MAINTENANCE e ALL PRINTED CIRCUIT CARDS ARE UNDER WARRANTY FOR ONE YEAR AFTER DATE OF SALE e ALLPRINTED CIRCUIT CARDS MAY BE FACTORY REPAIRED AT A NOMINAL FEE FOR PARTS AND LABOR AFTER WARRANTY PERIOD 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 trouble shooting portion of this manual The necessary documentation is contained within this manual 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 performed more easily than can be accomplished in the field To test the ACC 22B an internal 120 Hz test frequency has been provided Failure conditions are listed and the possible corrective actions given to eliminate the observed problem ACC 22B Page 17 of 19 HP 206
20. ger threshold above the background noise present The low level flowmeter signal is then passed through a special conditioning chain where it is filtered amplified and shaped into a train of digital pulses whose frequency is non linearly related to the volume flow rate The digital pulse train is then passed through the linearizer where the offset frequency signal is injected into it For flow rates within the range of the meter the linearizer output will be linearly related to the volumetric flow rate In addition this circuitry drives the low flow out of range cut out circuit which effectively turns off the offset oscillator based on the setting of the cut out circuit The signal entering the frequency to analog converter is passed through a combination of divide by N and DIP switch matrix The 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 filtered into an analog voltage that is proportional to flow The output amplifier will take this voltage and perform either a voltage to voltage amplifier or voltage to current amplifier Finally the output is divided by 8 to reduce irregular pulses spacing Then the pulse train enters a buffer and an attenuator simultaneously The buffer output produces a square wave pulse which can be used as a CMOS TTL compatible output The attenuator produces a c
21. he meter the linearizer output will be linearly related to the volumetric flow rate In addition this circuitry drives the low flow out of range cut out circuit which effectively turns off the offset oscillator based on the setting of the cut out circuit The signal entering the frequency to analog converter is passed through a combination of divide by N and DIP switch matrix The 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 filtered into an analog voltage that is proportional to flow ACC 22B Page 11 of 19 HP 206 Finally the output is divided by 8 to reduce irregular pulses spacing Then the pulse train enters a buffer and an attenuator simultaneously The buffer output produces a square wave pulse which can be used as a CMOS TTL compatible output The attenuator produces a capacitor coupled AC output which is suitable for driving other signal conditioners indicators or controllers which require an AC signal input The power supply takes the available input power either 115 220 VAC or DC voltage depending on Model option selected and provides the power required by the various circuitry A stable oscillator is provided which generates a 120 Hz test signal which may be used to perform tests on the ACC22B
22. in workmanship and material provided that such equipment was properly selected for the service intended properly installed and not misused Equipment which is returned transportation prepaid to Hoffer Flow Controls within 12 months after delivery of goods or 18 months from date of shipment on equipment for destination outside the United States and is found by Hoffer Flow Controls inspection to be defective in workmanship or material will be repaired or replaced at Hoffer Flow Controls sole option free of charge and returned shipped using the lowest cost transportation prepaid In the event of product failure contact Hoffer Flow Controls at 252 331 1997 or 800 628 4584 for issuance of a Returned Material Authorization RMA number ENCLOSURE DETAIL The ACC22B is may be packaged in either the General Purpose case Style 1 in an Explosion Proof case Style 4 or in the NEMA 4 case style 5 Dimensions are given in Figures 1 2 1 3 and 1 4 Figure 1 2 General Purpose Case Style 2 JIMENSIONS ARE IN INCHES ACC 22B Page 4 of 19 HP 206 Figure 1 3 Explosion Proof Case Style 4H and 4HO OPTIONAL O RING REMOVABLE COVER 4870 ALL DIMENSIONS ARE IN INCHES Figure 1 4 NEMA 4 Case Style 5
23. information to correctly install operate maintain and troubleshoot the Model ACC22B frequency to voltage current converter The ACC22B is intended to provide the user with a suitable interface between a frequency generating device and a data acquisition system This manual is organized to provide ease of use Individual sections are provided to cover the Introduction Installation Functional Description Calibration and Maintenance and Troubleshooting Illustrations have been used to improve the clarity of information provided in this manual ACC 22B i HP 206 THIS PAGE LEFT INTENTIONALLY ACC 22B i HP 206 1 INTRODUCTION 1 1 INTRODUCTION The Model ACC22B is a linearizer accessory which implements the frequency injection method of eliminating the nonlinear transfer characteristic of the Mini Flowmeter Series The output frequency from the Mini Flow Series is linear with respect to flow However a plot of frequency versus rate will indicate that the line does not pass through zero This will result in a K Factor which will vary with the flow rate The ACC22B utilizes circuitry which standardizes the K Factor of the Mini Flow Series so that totalizing can be accomplished The ACC22B provides a pulse output which is suitable for driving other signal conditioners indicators or controllers which require a pulse input The optional analog outputs may be configured as a current or voltage which is suitable for computer interface
24. ing information available BEFORE contacting FOR NON WARRANTY REPAIRS OR 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 Repairinstructions and or specific problems relative 2 Model and serial number of the product and to the product 3 Repairinstructions and or specific problems relative HFC 9708 to the product LIMITED WARRANTY HOFFER FLOW CONTROLS INC 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 and or replacement of nonconforming goods as provided in the following paragraphs In the event Purchaser
25. the input frequency range PULSE SCALER A dual in line DIP switch located on either the PCA 114 or PCA 115 which is used in programming the desired pulse output scaler of 1 2 4 8 16 32 64 or 128 Unit shipped with 8 as standard RANGE SELECT A dual in line DIP switch located on the PCA 112 which is used in programming the module to accept an input frequency range OFFSET FREQ ADJ internal 20 turn adjustment on the PCA 115 which is used adjust the equivalent offset frequency of the flowmeter Adjustment range is 0 00 to 150 0 HZ ACC 22B Page 13 of 19 HP 206 Figure 4 1 Control and Adjustment Detail PULSE OUTPUT TYPE SE OUTPUT SELECTION SELECTION HEADER 1 OPEN COLLECTOR EQUIP SHUNT 3 2 TIL CMOS EQUIP SHUNT 1 3 4 c 3 AC SQUARE WAVE EQUIP SHUNT 1 2 4 113 OR PCA 114 4 HIGH LEVEL PULSE EQUIP SHUNT 1 3 POSITION 0 IS A FACTORY OPTION CALER SELECTION DIVIDE BY SWITCH SETTING PCA 115 PCA 112 O FACTORY OPTION GN RANGE SELECTION F MAX SWITCH SETTING 300 600 600 1200 1200 2400 2400 4800 DPU DOO OFFSET FREQUENCY ADJ IS SET A d 9 TO 10 TIMES DESIRED OFFSET AT OFFSET FREQ TEST POINT WITH AB RESPECT TO COMMON RANGE SELECT OFFSET FREQ ADJ OFFSET FREQ TEST POINT
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