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16
4.2
Power Supply Specifications and Connection
•
Use independent linear direct current power supply for pressure transmitter. Large
resistive load results in high pressure drop.
•
Therefore, it is recommended to consider the resistance across the signal cable, display
meter and other equipment to ensure sufficient voltage is provided to the pressure
transmitter for its normal operation.
Standard current signal output: 12-30VDC, Current signal output with HART: 16.5-55VDC,
Current signal output with intrinsic safety: 12-30VDC
Modbus-RTU/RS485 signal output: 5VDC/9-30VDC
•
Remove the housing cover on terminal compartment side. Do not remove the cover in
explosive atmospheres when the circuit is live.
Label Two Wires Three Wires Four Wires
+
Power +
Power +
Power +
-
Signal -
Power -
Power -
A
B
Signal -
NOTE
•
4-20mA can be 2 or 3-wire; 1-5vdc is 3-wire; Modbus is 4-wire.
•
Power supply connections:
Connect power supply ‘+’ terminal to transmitter ‘+’ terminal.
Connect signal ‘+’ terminal to transmitter ‘-’ terminal.
Connect signal ‘-’ terminal to power supply ‘-’ terminal.
Do not connect power signal wiring to the test terminals as it could damage
the test diode.
Fig 2: Power Supply Connection
3
1
2
+
-
P+
P-
Po
w
er
S-
S+
Sig
na
l
Transmitter
terminals
