Model ACC7B Signal Conditioner (DC)
Contents
1. 1 STYLE 1 CASE GENERAL PURPOSE 3H O MEETS CLASS 1 DIV 1 AND 2 GROUP D ONLY CLASS II GROUPS E F G CLASS III NEMA 4X WITH O RING CERTIFIED CSA UL BODY KILARK GECCT 3 STOCK 200 0945 FLAT COVER STOCK 200 0533 KILARK GECBC 3BH O MEETS CLASSI DIV 1 AND 2 GROUPS A B C DCLASS 1 ZONES 1 AND 2 GROUPS IIB H2 IIA CLASS II DIV 1 AND 2 GROUPS E F G CLASS III NEMA 3 4 7 B C D 9 E F G CERTIFIED CENELEC CSA UL FM BODY KILARK STOCK 200 0406 DOME COVER STOCK 4200 0405 KILARK HK2D NOTE INSERT X IN MODEL NUMBER FOR EVERY OPTION NOT SPECIFIED ACC 7B Page 3 of 17 HP 244 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 Auth2. ACC 7B HP 244 THIS PAGE LEFT INTENTIONALLY ACC 7B HP 244 PREFACE This manual provides all the necessary information to correctly install operate maintain and troubleshoot the Model ACC 7B preamplifier interface The ACC 7B is intended to provide the user with a suitable pulse 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 7B i HP 244 THIS PAGE LEFT INTENTIONALLY ACC 7B ii HP 244 1 1 1 INTRODUCTION INTRODUCTION The Model ACC7B is a preamplifier with wave shaping that allows convenient interfacing between the turbine flowmeter and digital electronics The output signal has a square pulse wave form Outputs are provided to suit most users requirements Summation of the pulsing signal relates directly to the total flow throughput The frequency of the signal relates directly to the flow rate or the velocity The input signal conditioning circuitry is designed to accept the low level turbine flowmeter signal while providing rejection of unwanted noise and spurious signals Two output signals are available The first is a TTC CMOS compatible output The second is an open collector of
3. 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 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 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 WAR
4. 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 was 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 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 parts 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 e ALL PRINTED CIRCUIT CARDS ARE WARRANTED FOR ONE YEAR AFTER DATE OF SALE e ALL PRINTED 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
5. package should then be marked with a sensitive electronic device caution label conforming to MIL STD 129 appendix C Theequipment 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 Appen C Clearly mark the factory provided RMA number on all paperwork and shipping boxes ACC 7B Page 7 of 17 HP 244 THIS PAGE LEFT INTENTIONALLY ACC 7B Page 8 of 17 HP 244 2 2 1 2 2 INSTALLATION INSTALLATION WIRING LAYOUT FOR INTERCONNECTIONS 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 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 INSTAL
6. the field thereby reducing the time a unit is out of service ACC 7B Page 15 of 17 HP 244 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 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 OBSERVED CONDITION e UNIT DOES NOT PRODUCE A PULSE OUTPUT WITH FLOW PRESENT e PULSE OUTPUT e WITH NO FLOW PRESENT ACC 7B POSSIBLE CAUSE POWER LOSS BAD PICKUP COIL OR CABLE STALLED TURBINE FLOWMETER BAD ACC7B SENSITIVITY ADJUSTED FULLY COUNTER CLOCKWISE INPUT NOISE BAD PICKUP COIL OR CABLE EXTREME SHOCK OR VIBRATION OF PIPING POWER SUPPLY MALFUNCTION BAD ACC7B Page 16 of 17 CORRECTIVE ACTION CHECK INTERCONNECTING WIRING AND HOST SYSTEM CHECK PICKUP COIL AND CABLE FOR CONTINUITY AND LEAKAGE REPLACE AS REQUIRED REMOVE FLOWMETER AND REPAIR AS REQUIRED BY MANUFACTURERS RECOM MENDATIONS REPAIR OR REPLACE ADJUST SENSITIVITY TURN SENSITIVITY CCW UNTIL FALSE OUTPUT STOPS CHECK PICKUP COIL AND CABLE FOR CONTINUITY ANDLEAKAGE REPLACE AS REQUIRED DAMPEN OR RELOCATE PIPING CHECK AND REPAIR AS REQUIRED REP
7. 0 POWER INPUT INIERMAL COMMON AMPLIFIER COMPARITOR OUTPUT AMPLIFIER FLOWMETER ACC 7B Page 12 of 17 HP 244 4 CALIBRATION PROCEDURE 4 1 4 2 4 3 INTRODUCTION In general all flow measurement systems supplied by Hoffer Flow Controls have been factory tested and configured as specified by the user at the time of purchase free of charge The ACC7B requires no field calibration REQUIRED TEST EQUIPMENT In order to adjust the sensitivity and troubleshoot the ACC7B the following suggested equipment list is provided PART MANUFACTURE NUMBER DESCRIPTION 8060 True RMS Multimeter 8 T000 Adjustment Tool CONTROLS AND ADJUSTMENTS SENSITIVITY A twenty turn control used to set the threshold sensitivity level above the ambient noise pickup NOTE IT IS NECESSARY TO OPEN THE COVER OF THE ENCLOSURE BY REMOVING TWO SCREWS ON SIDE OF BOX ANDLIFTING COVER TWO PRINTED CIRCUIT CARDS ARE ATTACHED THE RANGE DIP SWITCH MAY BE PROGRAMMED WITH A PEN INPUT POWER SHOULD BE REMOVED DURING THIS STEP ACC 7B Page 13 of 17 HP 244 Figure 4 1 Control and Adjustment Detail ACC 7B Page 14 of 17 HP 244 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
8. 32 FUNCTIONAL DESCRIPTION INTRODUCTION The ACC7B is a preamplifier which will provide a frequency pulse output 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 pulse output proportional to flow rate The electronics unit requires input power of 8 to 35 VDC standard and 12 to 35 VDC when equipped with a 0 to 10 volt pulse output The frequency signal which is generated from the flowmeter 1 connected to the ACC7B 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 pulse train is then fed into the output stage which will generate the required pulse output level desired ACC 7B Page 11 of 17 HP 244 Figure 3 1 Block Diagram TO FUNCTIONAL INTERNAL BLOCKS 77 POWER SUPPLY 4
9. AIR OR REPLACE HP 244 5 3 REPLACEMENT PARTS PART NUMBER DESCRIPTION ACC7B 1 1 3 TTL CMOS PULSE OUTPUT ACC7B 2 1 3 OPEN COLLECTOR PULSE OUTPUT ACC7B 3 1 3 OPEN COLLECTOR WITH PULLUP TO V ACC7B 5 1 3 0 TO 10 VDC PULSE OUTPUT ACC 7B Page 17 of 17 HP 244
10. LATION OF THE ACC7B The model ACC7B 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 terminal interconnections Connection 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 cover is installed Connect two conductor shielded signal cable from the flowmeter to terminals 3 and 2 Connect the shield to terminal 2 Ground the shield at one end only ACC 7B Page 9 of 17 HP 244 The ACC7B is factory wired to operate either from a regulated 5V DC or an unregulated but filtered voltage of 8 to 35V DC Verify correct power is available for the power option selected Connect the plus voltage to terminal 4 and connect the power return to terminal 5 The output signal from the ACC7B is available in several forms see model number designation for output type specified For the pulse output connect wire to terminal 1 and connect pulse common to terminal 2 Figure 2 1 Installation wiring PULSE OUTPUT OUT BLK PULSE COMMON lt TO FLOWMETER DC POWER INPUT 4 7 Page 10 of 17 HP 244 3 3 1
11. Model ACC7B PREAMPLIFIER SIGNAL CONDITIONER USER S MANUAL HP 244 August 2004 H 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 OF 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 item to be connected and locate
12. RANTY 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 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 nonconforming goods as provided in the follow
13. Y 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 iib ve o Ein EVER FIN RR we wee hen ee i L Introd ClOB 1 1 1 Introduction EUER EG 1 1 2 Performance Characteristics 2 1 3 Ordering Information 3 1 4 Wartahty erm ee a eb GE 4 1 5 Enclosure Detail VOCE ges 5 1 6 Shipping and 7 2 Installation RR RER RE RE e 9 2 1 Installation Wiring Layout for Interconnections 9 2 2 Installation of the ACC7B 9 3 Functional Description 11 3 1 Introduction 11 3 2 Principle of Operation 11 4 Calibration Procedure 13 4 1 Introduct OM cec E ER wR ke ERE ER 13 4 2 Required Test Equipment 13 4 3 Controls and Adjustments 13 2 Maintenance enses OEUVRE ER PR each 15 5 1 Introduction C bc ch SA Eug 15 5 2 Trouble Shooting and Maintenance 15 5 3 Replacement 2 rep E 17
14. a medium power transistor The unit is powered by a user supplied filtered DC voltage An on board regulator provides the required regulation and noise rejection ACC 7B Page 1 of 17 HP 244 12 PERFORMANCE CHARACTERISTICS INPUT e PULSE OUTPUT e INPUT POWER e ENVIRONMENTAL e ENCLOSURES e Input protected RF and band pass filtered adjustable trigger level Input Impedance 40 kilo ohm nominal Trigger Sensitivity 10 millivolt RMS minimum 10 to 1000 Hz Input over voltage protected to 120 volts RMS absolute max Open Collector Maximum off state voltage 60 volts Maximum current 1 0 Amps TTL CMOS Logic 0 0 0 volts Logic 1 5 0 volts Output capable of driving 6 standard TTL loads 8 to 35 VDC unregulated or 5 VDC 5 regulated Note 12 to 35 VDC is required when unit is equipped with pulse opt 5 Required current 15 mA max Operating 0 70 C Storage 20 70 C General purpose case standard NEMA 4 Explosion Proof ACC 7B Page 2 of 17 HP 244 13 ORDERING INFORMATION MODEL ACCT7B PULSE OUTPUT INPUT POWER ENCLOSURE STYLE PULSE OUTPUT MODEL 7 OPTION 1 TTL CMOS 2 OPEN COLLECTOR 3 COLLECTOR WITH PULL UP TO V 5 0 10 V SQUARE WAVE REQUIRED 12 35 VDC POWER INPUT POWER MODEL ACC7B OPTION 1 UNREGULATED 8 35 VDC 2 REGULATED 5 VDC ENCLOSURE STYLE MODEL 7
15. ing 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 HFC s discretion HFC does not wa
16. orization RMA number ACC 7B Page4 of 17 HP 244 1 5 ENCLOSURE DETAIL The ACC7B 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 1 4 and 1 5 Figure 1 2 General Purpose Case Style1 ALL DIMENSIONS ARE IN INCHES ACC 7B Page 5 of 17 HP 244 Figure 1 3 Explosion Proof Case Style 3 1 P 3 13 16 ALL DIMENSIONS ARE IN INCHES Figure 1 4 NEMA 4 Case Style 5 E 1 1 2 1 1 2 ALL DIMENSIONS ARE IN INCHES ACC 7B Page 6 of 17 HP 244 1 6 SHIPPING AND HANDLING CAUTION The ACC7B 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 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
17. rrant 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 PURCHASER S SOLE AND EXCLUSIVE REMED
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