Service Manual
Contents
1. s TOTAL RECEIVER RESISTANCE 3 RECALIBRATION PROCEDURE Transmitter If the transmitter needs to be recalibrated use the following procedure 1 With the transmitter connected to the companion receiver insert an accurate milliammeter in series with the current loop Full scale range should be approximately 30 mA 2 Connect a controllable pressure source to one leg of a tee with the second leg connected to the high pressure port of the pressure transmitter and the third leg to an accurate test gage or manometer The low pressure port must be vented to atmosphere Calibration must be performed in the same position in which the unit will be mounted 3 Apply electrical power to the unit and allow it to stabilize for 10 minutes 4 With no pressure applied use the Zero Adjust controls on the front of unit to set display to the center of the adjustment range First press and hold the A key until it reaches its limit and record the value Next do the same with the W key Add readings and divide by two to establish the average Example If maximum A reading is 0 22 and minimum reading is 0 14 total span is 0 36 Dividing 0 36 by 2 equals 0 18 Subtracting 0 18 from 0 22 equals 0 04 Adjust controls as necessary until display reads exactly 0 04 5 Next with no pressure applied to the pressure transmitter adjust the Transmitter Zero Control on the back of the unit so loop current is 4 00 mA See Fig B 62. SERIES 620 PRESSURE INDICATING TRANSMITTER Specifications Installation and Operating Instructions PANEL MAX THICKNESS 1 4 6 350 BULLETIN E 48 ZERO ADJUST The Dwyer Series 620 Pressure Indicating Transmitter is a com pact 1 16 DIN instrument for measuring and controlling pressure of air or compatible gases providing a 31 4 digit LCD display plus a standard 4 20 mA transmitter output signal Positive negative or differential pressures can be measured with 0 5 of full span accuracy English ranges are available from 0 3 in w c to 0 100 psi metric ranges from 0 75 kPa to 0 690 kPa All models employ a versatile circuit design which enables operation in your choice of 2 3 or 4 wire DC or 4 wire AC current loops SERIES 620 ENGLISH MODELS amp RANGES MODEL NUMBER RANGE MAXIMUM PRESSURE 620 3 620 6 620 10 620 20 620 40 620 100 620 200 620 1000 620P 10 620P 20 620P 30 620P 50 620P 100 0 3 in w c 0 6 in w c 0 10 in w c 0 20 in w c 0 40 in w c 0 100 in w c 0 200 in w c 0 1000 in w c 0 10 PSI 0 20 PSI 0 30 PSI 0 50 PSI 0 100 PSI 5 PSI 5 PSI 5 PSI 11 PSI 11 PSI 29 PSI 29 PSI 150 PSI 58 PSI 58 PSI 58 PSI 150 PSI 150 PSI SERIES 620 METRIC MODELS amp RANGES MODEL NUMBER 620 1 5 kPa 620 2 5 kPa 620 5 kPa 620 10 kPa 620 25 kPa 620 50 kPa 620 138 kPa 620 207 kPa 620 249 kPa 620 345 kPa 620 690 kPa 620 0 75 kPa 0 0
3. Thermal Errors DWYER INSTRUMENTS INC P O BOX 373 MICHIGAN CITY INDIANA 46361 U S A 4mA DC 16 mA DC 0 5 of full span output Includes linearity hysteresis and repeatability Adjustable to 0 5 of full span 10 minutes 20 to 120 F 6 7 to 49 C 0 02 F typical Telephone 219 879 8000 Fax 219 872 9057 INSTALLATION 1 LOCATION Select a location where the temperature of the unit will be between 20 F and 120 F Distance from the receiver is limited only by total loop resistance See Electrical Connections The tubing feeding pressure to the instrument can be run practi cally any length required but long lengths will increase response time slightly Mount the instrument in a location that will not be subject to excessive temperature shock or vibration All models are designed for mounting in an enclosed panel Select the mounting position for the instrument on the panel Prepare the panel by cutting and deburring the required opening Refer to Figure A From the front panel slide the instrument through the cutout The housing gasket should be against the housing flange before installing From the rear of the panel slide the mounting collar over the hous ing Hold the housing with one hand and using the other hand push the collar evenly against the panel until the springs are com pressed The ratchets will hold the mounting collar and housing in place 2 POSITION A horizontal position is recommended
4. pressure connections pointing horizontally since that is how all standard models were originally spanned and zeroed at the factory They can be used at other angles but final spanning and zeroing must be done while transmitter is in that alternative position 3 PRESSURE CONNECTIONS Two integral barbed tubing con nections are provided for use with 1 8 3 mm I D vinyl or rubber tubing Attach tubing from positive pressure source to port marked HI or from negative vacuum source to port marked LO In either case opposite port must be vented to atmosphere For differential pressures the higher source is connected to the HI port and the lower to the LO port ELECTRICAL CONNECTIONS CAUTION DO NOT EXCEED SPECIFIED SUPPLY VOLTAGE RATINGS PERMANENT DAMAGE NOT COVERED BY WAR RANTY WILL RESULT THIS UNIT IS NOT DESIGNED FOR 120 OR 240 VOLT AC LINE OPERATION Electrical connections to the Series 620 Pressure Transmitter are made at the terminal block located on the back of the unit The terminal block is marked 1 2 3 and 4 Refer to Figure B for loca tion of the terminal block span and zero adjust potentiometers SPAN ADJUSTMENT ZERO ADJUSTMENT FIG B Wire Length The maximum length of wire connecting the pres sure transmitter and receiver is a function of wire size and receiver resistance Wiring should not contribute more than 10 of the receiver resistance to total loop resistance For extremely long runs over 100
5. Apply full range pressure and adjust loop current to 20 mA using the Transmitter Span Control See Fig B 7 Relieve pressure and allow pressure transmitter to stabilize for 2 minutes 8 Zero and Span controls are slightly interactive so repeat steps 4 through 7 until zero and full range pressure consistently produce loop currents of 4 and 20 mA respectively 9 Remove the milliammeter from the current loop and proceed with final installation of the pressure transmitter and receiver Voltage Input Series 620 Pressure Transmitter can be easily adapted for receivers requiring 1 5 or 2 10 VDC input Insert a 249 ohm 1 2 watt 1 5 VDC or 499 ohm 2 10 VDC resistor in series with the current loop but in parallel with the receiver input Locate this resistor as close as possible to the input Because resistor accuracy directly influences output signal accuracy we recom mend use of a precision 0 1 tolerance resistor to minimize this effect See Figs H and J 3 WIRE CONNECTION 1 5 2 10 VDC OUTPUT PRESSURE TRANSMITTER FIG H 4 WIRE CONNECTION 1 5 2 10 VDC OUTPUT POWER PRESSURE SUPPLY 10 35 VDC 16 26 VAC TRANSMITTER FIG J Copyright 1997 Dwyer Instruments Inc Printed in U S A 1 97 MULTIPLE RECEIVER INSTALLATION An advantage of the standard 4 20 mA DC output signal provided by the Series 620 Pressure Transmitter is that any number of receivers can be connected in series in the current lo
6. or damage could result Control loop polarity must be observed in the following respect Although power supply terminals 1 and 2 are not polarized the receiver must be connected between terminal 3 of indicator and negative side of power supply 3 WIRE CONNECTION POWER SUPPLY 10 35 VDC PRESSURE TRANSMITTER RECEIVER DWE FIG D 4 Wire Operation An external power supply delivering 10 35 VDC with a minimum current capability of 40 mA DC per trans mitter or 16 26 VAC with a minimum current capability of 80 mA AC per transmitter is required See Fig E for connection of power supply transmitter and receiver The range of the appropri ate load resistance R for the DC or AC power supply available is expressed by the formulas and graphs in Figs F and G Shielded cable is recommended for control loop wiring Do not employ a separate ground in 4 wire operation Unit will not function properly and or damage could result Control loop polarity must be observed terminal 3 is negative and 4 is positive Power supply terminals 1 and 2 are not polarized 4 WIRE CONNECTION POWER SUPPLY 10 35 VDC 16 26 VAC Pa FIG E POWER SUPPLY VOLTAGE VDC 2 3 or 4 wire MAXIMUM VALUE 1300 N _ Vps 10 0 Ru MAX 0 mADC TOTAL RECEIVER RESISTANCE 10 13 15 20 25 30 35 40 VDC FIG F POWER SUPPLY VOLTAGE VAC 4 wire 1300 MAXIMUM VALUE 1200 Q 3 8 8 Ri MAX 65 Vps 490 o s
7. 0 feet choose receivers with higher resistance to minimize size and cost of connecting leads Where wiring length is under 100 feet hook up wire as small as 22 AWG can be used 2 Wire Operation An external power supply delivering 10 35 VDC with minimum current capability of 40 mA DC per transmitter must be used to power the control loop See Fig C for connection of the power supply transmitter and receiver Note the jumper between 3 and 4 The range of the appropriate receiver load resis tance R for the DC power supply voltage available is expressed by the formula and graph in Fig F Shielded two wire cable is rec ommended for control loop wiring If grounding is required use negative side of the control loop after the receiver Otherwise in 2 wire operation it is not necessary to observe polarity of control loop connections 2 WIRE CONNECTION POWER PRESSURE RECEIVER SUPPLY WIRE 10 35 VOC 3 TRANSMITTER a JUMPER FIG C 3 Wire Operation An external power supply delivering 10 35 VDC with minimum current capability of 40 mA DC per transmitter is required See Fig D for connection of power supply transmitter and receiver The range of the appropriate receiver load resistance R for the DC power supply available is expressed by the formula and graph in Fig F Shielded cable is recommended for control loop wiring Do not employ a separate ground in 3 wire operation Unit will not function properly and
8. 75 kPa 0 1 50 kPa 0 2 50 kPa 0 5 00 kPa 0 10 00 kPa 0 25 0 kPa 0 69 0 kPa 0 138 0 kPa 0 207 kPa 0 249 kPa 0 345 kPa 0 690 kPa MAXIMUM PRESSURE 34 kPa 34 kPa 34 kPa 76 kPa 76 kPa 200 kPa 400 kPa 400 kPa 400 kPa 1034 kPa 1034 kPa 1034 kPa 1 49 64 E 44 85 MOUNTING COLLAR SHOWN IN POSITION GASKET smi SLIDE COLLAR ONTO THE HOUSING BEFORE THE REAR TERMINALS SPRING LOOP 1 49 64 nee 17 8 44 85 ESEME 47 63 H Deve 14 S 4 15 32 ni Pare 16 350 113 5 L 29 64 11 51 al 7 8 47 63 3 43 64 193 27 z PANEL CUTOUT 1 49 64 FOR SINGLE 44 85 INSTRUMENT SPECIFICATIONS GENERAL Pressure Connections Media Compatibility Electrical Connections Housing Weight Adjustments ELECTRICAL Power Supply Output Signal Loop Resistance Current Consumption PANEL CUTOUT FOR 2 INSTRUMENTS MOUNTED TOP AND BOTTOM OR SIDE BY SIDE ALL TOLERANCES ARE 010 000 250 000 FIG A Barbed 1 8 3 mm I D tubing Air and non corrosive gases Terminal block Gray PVC type 8 5 ounces 241 grams Accessible potentiometers 10 35 VDC 2 3 or 4 wire 16 26 VAC 4 wire 4 20 mA DC limited at 38 mA DC 0 1300 ohms DC max 0 1200 ohms AC max DC 38 mA max AC 76 mA max PERFORMANCE AT 70 F 21 1 C Zero Output Full Span Output Accuracy Span and Zero Warm up Time ENVIRONMENTAL Operating Temperature
9. op Thus an A 701 Digital Readout an analog panel meter a chart recorder process controlling equipment or any combination of these devices can be operated simultaneously It is necessary only that each be equipped with a standard 4 20 mA input and that proper polarity of the input connections be observed when inserting the device into the current loop If any of the receiving devices displays a negative or downscale reading this indicates that the signal input leads are reversed MAINTENANCE Upon final installation of the Series 620 Pressure Transmitter and the companion receiver no routine maintenance is required A periodic check of the system calibration is recommended The Series 620 Pressure Transmitter is not field serviceable and should be returned freight prepaid to the factory if repair is required Fr No 01 440938 00
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