Omega DPG5000 manual MA Transmitter Option, Typical 4-20 mA Circuit

DPG5000 M3366/0606

7. 4-20 mA Transmitter Option

When equipped with this option the gauge no longer operates from batteries but instead is “Loop Powered”. The loop connection is made to a 6 pin receptacle located at the rear of the unit (a mating plug is supplied). A voltage of between 9 and 32 VDC must be maintained at this connection (Pin A is “+” and Pin B is “-” see sketch) to insure proper operation. Completion of the earth or system ground (Pin F) is recommended for proper circuit protection.

Power supply voltage must be sufficient to maintain a minimum of 9 VDC at the gauge terminals after “dropping” voltage across RL at full scale current (20 mA). Example: If RL = 250 ohm then “drop” is 0.02 Amps X 250 ohm = 5 volts. Therefore power supply minimum is 5 V + 9 V = 14 V.

RE-CALIBRATION: The procedure is the same as in step 4, except that there are 2 sets of zero and span adjustments. The front panel controls affect the display and the rear controls (remove “battery” door) affect the 4/20 mA signal.

Typical 4-20 mA Circuit

Gauge		Process
Connector		Controller
A	+ EXCITATION	+Vin
B	– EXCITATION	R L

C

4-20 mA

DCURRENT

LOOP

E

F