Model ACC28 Signal Converter
Contents
1. The course range adjustment is accomplished by selecting a switch position on a DIP switch located on the PCA 66 printed circuit card See Table 4 1 to determine required switch position and set into switch as shown in Figure 4 1 for anticipated F MAX ACC 28 Page 13 of 18 HP 247 Table 4 1 Range Select INPUT FREQUENCY SWITCH POSITION 300 600 Hz 600 1200 Hz 1200 2400 Hz 2400 4800 Hz I ER Connect a digital voltmeter as shown in Figure 4 2 aj AJo Figure 4 2 Test Setup Adjust ZERO control for desired zero voltage i e 0 VDC See test setup shown in Figure 4 2 Inject the test frequency equal to Fmax while adjusting SPAN for current equal to the desired Full Scale voltage output 1 1 VDC or 5 VDC Adjust ZERO control for desired zero voltage 1 0 VDC See test setup shown in Figure 4 2 Iterate SPAN and ZERO adjustment for the desired current output until no change is observed ACC 28 Page 14 of 18 HP 247 5 MAINTENANCE 5 1 5 2 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 preventative maintenance and repairs The bearing type used in the flowmeter was chosen to give compromise between2. 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 sensor 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 of the wiring reduces the chance of potential problems INSTALLATION OF THE ACC28 The model ACC28 should be placed in a convenient location which maintains access to the unit should repairs or readjustment be required Refer to wiring installation Figure 2 1 for appropriate terminals for interconnections Connections to the terminal block should be carefully dressed to avoid having bare wires extending past 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 prevent problems when the cover is installed Connect two conductor shielded cable from the flowmeter Connect shield to ACC28 only Unit is powered by a DC voltage which mu
3. to repair replacement or recalibration of the flowmeter or perhaps a change in the analog output span 4 2 REQUIRED TEST EQUIPMENT In order to calibrate and troubleshoot the ACC28 the following suggested equipment list is provided MANUFACTURER PART NUMBER DESCRIPTION Simpson Function Generator Multi Function Counter Adjustment Tool ACC 28 Page 11 of 18 HP 247 43 _CONIROLS AND ADJUSTMENTS SENSITIVITY RANGE ZERO A twenty turn control used to set the threshold sensitivity level above the ambient noise pickup A dual in line DIP switch located within the enclosure which is used to program the module to accept an input frequency range SPAN A multiple turn adjustment which is used to set the current output signal to the desired span corresponding to the equivalent flow range 1 0 to 5 VDC 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 0 VDC NOTE TO OPEN THE COVER OF THE ENCLOSURE BY REMOVING TWO SCREWS ON SIDE OF BOX AND LIFTING COVER TWO PRINTED CIRCUIT CARDS ARE ATTACHED THE RANGE DIP SWITCH MAY BE PROGRAMMED WITH A PEN Figure 4 1 Control and Adjustment Detail RANGE SELECT 1 REMOVE FOR ANALOG OUTPUT R PRINTED CIRCUIT ASSEMBLY 2 TURN ON DESIRED RANGE POSITION USING A BALL POINT PEN OR SIMILAR OBJECT SEE RANGE SELECT DETAIL 3 REA
4. 1 1 0 TO 1 VDC OUTPUT ASSEMBLY ACC28 5 1 1 0 TO 5 VDC OUTPUT ASSEMBLY ACC 28 Page 18 of 18 HP 247
5. 1 1 2 ALL DIMENSIONS IN INCHES ACC 28 Page 4 of 18 HP 247 1 6 SHIPPINGAND HANDLING CAUTION The ACC28B is a static sensitive device 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 IL 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 Clearly mark the factory provided RMA number on all paperwork and shipping packaging ACC 28 Page 5 of 18 HP 247 THIS PAGE LEFT INTENTIONALLY ACC 28 Page 6 of 18 HP 247 2 2 1 2 2 INSTALLATION INSTALLATION WIRING LAYOUT FOR INTERCONNECTIONS In considering the interconnections between the flowmeter and
6. HP 247 THIS PAGE LEFT INTENTIONALLY ACC28 HP 247 ACC28 This manual provides all the necessary information to correctly install operate maintain and troubleshoot the Model ACC28 frequency to voltage converter The ACC28 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 i HP 247 THIS PAGE LEFT INTENTIONALLY ACC28 ii HP 247 1 INTRODUCTION 1 1 INTRODUCTION The Model ACC28 is a frequency to voltage converter that allows convenient interfacing to the turbine flowmeter which provides an analog voltage output proportional to flow rate The input signal conditioning circuitry is designed to accept the low level turbine flowmeter signal while providing rejection of unwanted noise and spurious signals The output signal is a DC voltage which is proportional to flow rate 1 2 PERFORMANCE CHARACTERISTICS INPUT Input protected RF and band pass filtered adjustable trigger level Input Impedance 40 kilo ohm nominal e Trigger Sensitivity 10 millivolt RMS minimum 10 Hz to 1000 Hz Over voltage 120 volts RMS absolute ma
7. and on any correspondence FOR WARRANTY RETURNS please have FOR NON WARRANTY REPAIRS the following information available BEFORE OR CALIBRATIONS consult contacting HOFFER FLOW CONTROLS HOFFER FLOW CONTROLS for current repair calibration charges Have 1 P O number under which the product the following information available was PURCHASED BEFORE contacting HOFFER FLOW 2 Model and serial number of the product CONTROLS under warranty and 3 Repair instructions and or specific 1 number to cover the COST of problems relative to the product the repair calibration HFC 9708 2 Model and serial number of the product and 3 Repair instructions and or specific problems relative 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 forthe 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 nonconform
8. is supplied separately ACC 28 Page 15 of 18 HP 247 ACC 28 Factory consultation is available to assist in diagnosing problems Please note that in some cases factory repairs can be performed more easily than can be accomplished in the field Failure conditions are listed and the possible corrective actions given to eliminate the observed problem Page 16 of 18 HP 247 OBSERVED CONDITION CORRECTIVE ACTION OUTPUT WITH NOISE INPUT SLOWLY NO FLOW TURN SENS POT CCW UNTIL FALSE INDICATION STOPS NOTE IN FULLY CCW POSITION THE UNIT WILL NOT OPERATE REPLACE PICKUP COIL DEFECTIVE ACC28 REPAIR OR REPLACE INCORRECT ZERO VERIFY THAT POWER SUPPLY READING WITH NO FLOW VOLTAGE IS WITHIN LIMIT UNIT IS OUT OF CALIBRATION RECALIBRATE DEFECTIVE ACC28 REPAIR OR REPLACE VOLTAGE EXCEEDS FLOWMETER BEING USED DESIRED SPAN BEYOND CALIBRATED SPAN OF 28 CALIBRATION 28 INCORRECT RECALIBRATE DEFECTIVE UNIT REPAIR OR REPLACE INCORRECT ANALOG LOAD RESISTANCE TOO SMALL OUTPUT NOISE PICKUP PRESENT ADJUST SENSITIVITY CALIBRATION OF ACC28 INCORRECT RECALIBRATE DEFECTIVE UNIT REPAIR OR REPLACE LARGE RIPPLE ON WRONG RANGE SWITCH ANALOG OUTPUT SELECTED RECALIBRATE FLOWMETER BEING OPERATED BELOW RANGE ADJUST RESPONSE CONTROL TO MINIMIZE RIPPLE ACC 28 Page 17 of 18 HP 247 5 3 REPLACEMENT PARTS PART NUMBER DESCRIPTION ACC28 1
9. item to be connected and locate the appropriate manual s and or drawing s Identify all model numbers exactly before making any connections 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 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
10. 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 THE GOODS WITHOUT LIMITING THE GENERALITY OF THE FOREGOING THIS EXCLUSION FROM LIABILITY EMBRACES THE PURCHASER S EXPENSES FOR DOWNTIME DAMAGES FOR WHICH THE PURCHASER MA Y BELIABLE 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
11. Model ACC28 MAG COIL FLOW RATE CONDITIONER FREQUENCY TO ANALOG VOLTAGE USER S MANUAL HP 247 January 2011 H HOFFER FLOW CONTROLS INC PERFECTING MEASUREMENT 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 ANY KIND WITH REGARD TO THIS MATERIAL INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES 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
12. PECIFIED ACC 28 Page 2 of 18 HP 247 1 4 WARRANTY Hoffer Flow Controls warrants that all equipment will be free from defects 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 15 ENCLOSURE DETAIL The ACC28 is may be packaged in either the General Purpose case Style 1 in an Explosion Proof case Style 3 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 1 ALL DIMENSIONS ARE IN INCHE ACC 28 Page 3 of 18 HP 247 Figure 1 3 Explosion Proof Case Style 3 ALL DIMENSIONS ARE IN INCHES Figure 1 4 NEMA 4 Case Style 5 1 1 2
13. 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 TABLE OF CONTENTS PREFACE Exe PUER Rer EUR NE ets 1 1 INTRODUCTION 4 ie eG SOS e pbs Ree DEUS 1 1 1 INTRODUCTION 1 1 2 PERFORMANCE CHARACTERISTICS 1 1 3 ORDERING INFORMATION 2 L4 WARRANTY RR 3 15 ENCLOSUREDETAIL eene 3 1 6 SHIPPING AND HANDLING 5 2 INSTALLATION ccs sev mb c ERG RE T PR ES 7 2 1 INSTALLATION WIRING LAYOUT FOR INTERCONNECTIONS eese 7 2 2 INSTALLATION OF THE ACC28 7 3 FUNCTIONAL DESCRIPTION 9 3 4 INTRODUCTION 9 3 2 PRINCIPLE OF OPERATION 9 4 CALIBRATION PROCEDURE 11 41 INTRODUCTION III 11 4 2 REQUIRED TEST EQUIPMENT esses 11 4 3 CONTROLS AND ADJUSTMENTS 12 4 4 PROGCEDURE HER Lee eee Peres 13 5 MAINTENANCE siso spends e ERR RR ee Tg eus 15 5 1 INTRODUCTION gu RR RR 15 5 2 TROUBLE SHOOTING AND MAINTENANCE 15 5 3 REPLACEMENT PARTS 18 ACC28
14. SSEMBLE IN LOWER CASE RANGE SELECT SWITCHES TABLE ONE RANGE SELECT SWITCH FOR F MAX 75 150 150 300 300 600 SWITCH 2 IS DEPRESSED FOR ILLUSTRATIVE PURPOSES ONLY 600 1200 NOTE 1200 2400 SELECT ONE SWITCH ONLY ALL OTHER SWITCHES MUST BE OFF 1 2 3 4 5 6 2400 4800 ACC 28 Page 12 of 18 HP 247 4 4 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 flowmeter 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 GPM max x Kaye Where is the maximum input frequency KAVE is the average calibration factor The analog output of the ACC28B 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 4 2 The oscillator s output frequency is set to equal F MAX as indicated on the frequency counter
15. ing 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 HFC the goods will be disposed of in
16. long life chemical resistance ease of maintenance and performance A preventative maintenance schedule should be established to determine the amount of wear which has occurred since last overhaul See users 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 if an abridged spare parts list is sought The recommended spare list may be found following this section and in the users manual for the flowmeter In case the flow measurement system malfunctions or becomes inoperative a trouble shooting procedure follows 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 TROUBLE SHOOTING AND MAINTENANCE 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 ANDLABOR AFTER WARRANTY PERIOD Incase 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 The necessary documentation is contained within this manual with the exception of the calibration data sheet for the turbine flowmeter This calibration
17. ombination of a divide by N and a DIP switch matrix The divide by N output is chosen whose pulse rate is between 75 and 150 Hz at the maximum flow rate measured This scaled pulse rate is then filtered into an analog voltage This voltage is proportional to volumetric flow rate The resulting output voltage related to flow is then fed into the output amplifier The output amplifier is a voltage to voltage amplifier and offers ZERO and SPAN adjustments and is available in standard process ranges of 0 1 VDC or 0 5 VDC ACC 28 Page 9 of 18 HP 247 Figure 3 1 Block Diagram AMPLIFIER TO FUNCTIONAL BLOCKS COMPARITOR lj t O Power INPUT INTERNAL POWER SUPPLY INTERNAL 7 COMMON RANGE SELECT OUTPUT AMPLIFIER ae VOLTAGE OUTPUT FLOWMETER RESPONSE ACC 28 Page 10 of 18 HP 247 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 free of charge All systems which underwent such a factory calibration have a calibration setup sheet included with the shipment This sheet 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
18. st be within 8 to 40 volts Connect power as outlined in installation drawing ACC 28 Page 7 of 18 HP 247 Figure 2 1 Installation wiring ACC 28 Page 8 of 18 HP 247 3 3 1 3 2 FUNCTIONAL DESCRIPTION INTRODUCTION The ACC28 is a frequency to voltage transmitter which will provide an analog output voltage proportional to rate of flow The unit is intended to provide the user with a suitable interface between a flow measurement sensor and a data acquisition system PRINCIPLE OF OPERATION A block diagram showing functional blocks of the unit is depicted in Figure 3 1 The principle of operation is as follows The electronics unit receives the signal form the flowmeter pickup coil and converts it to a current output proportional to flow rate The electronics unit requires power of 8 to 40 VDC The frequency signal which is generated from the flowmeter is connected to the ACC28 with a twisted shielded pair cable The signal enters 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 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 signal entering the frequency to voltage converter is passed through a c
19. x VOLTAGE OUTPUT Accuracy 05 of full scale Temperature drift 200 Available range 0 1 VDC 0 5 VDC Response time 0 5 seconds for 10 to 90 adjustable Output ripple less than 0 296 of F S Load resistance output can source up to 3 mA into a grounded load only INPUT POWER e 10 35 VDC unregulated 10 mA maximum ENVIRONMENTAL Operating 0 70 Storage 20 70 oC ENCLOSURES General purpose standard Case NEMA 4 Explosion Proof ACC28 Page 1 of 18 HP 247 1 3 ORDERING INFORMATION MODEL ACC28 ANALOG OUTPUT INPUT POWER ENCLOSURE STYLE ANALOG OUTPUT MODEL ACC28 OPTION 1 0 1 VDC 2 0 5 VDC INPUT POWER MODEL 28 OPTION 1 10 35 VDC ENCLOSURE STYLE MODEL 28 1 STYLE 1 CASE GENERAL PURPOSE 3H O MEETS CLASS 1 DIV 1 AND 2 GROUP D ONLY CLASS GROUPS E F CLASS NEMA 4X WITH O RING CERTIFIED CSA UL BODY KILARK GECCT 3 STOCK 5200 0945 FLAT COVER STOCK 2200 0533 GECBC 3BH O MEETS CLASS I DIV 1 AND 2 GROUPS A B C D CLASS 1 ZONES 1 AND 2 GROUPS H2 CLASS IL DIV 1 AND 2 GROUPS E CLASS NEMA 3 4 7 9 G CERTIFIED CENELEC CSA UL FM BODY KILARK HKB STOCK 200 0406 DOME COVER STOCK 200 0405 KILARK HK2D INSERT X IN MODEL NUMBER FOR EVERY OPTION NOT S
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