SOR 503FR Fixed Range Pressure Transmitter - Manual (Page 3)

Form 963 (03.13) ©SOR Inc. 3/4
Servicing
Current Loop
Milliameter
4-20mA
Case Ground
Red wire
Blue wire
Green wire
+
_
Transmitter
Power
Supply
The transmitter will drive into a resistive load, which is a function of the supply voltage.
This may be derived from the following formula:
As noted earlier, the minimum current the transmitter can supply is in the order of 3.3 mA.
If a reading of this nature is obtained, it is usually indicative of a fault condition, possibly
due to damage to the transmitter caused by over-pressurization or negative pressure being
applied to the transmitter.
The red wire is the positive power supply input, the blue wire is the negative power input,
and the green is case ground. Reverse connection will prevent the transmitter operating
due to its internal reverse polarity protection.
Voltage Divider
Red Wire
Blue Wire
Green Wire
Case Ground
+
_
Power
Supply
Transmitter
To display or
other process instruments
Resistive
Load
R
L
(Max) =
V
Supply
- 10V
This transmitter contains no user serviceable parts and cannot be repaired on site. It must
be returned to the factory. Disassembly of the instrument by unauthorized persons will
invalidate the warranty. If there is a risk of debris accumulating in the pressure port, it
should be very carefully cleaned.