Appendix C: Troubleshooting
4–20mA MONITORING: Problem 1 Can’t program 4–20mA range; or the unit won’t read the 4–20mA sensor.
Cause
Solution
The zone isn’t configured to read a 4–20mA sensor.
Press SET and CONFIGURE to program the zone. See Chapter 4 for information on zone configuration.
Problem 2 The zone input is not reading correctly.
Cause
Solution
a) No power connected to the transducer.
Connect a power supply as shown in Chapter 2.
b) Incorrect wiring.
Inspect wiring. Make sure polarity is correct as shown in Chapter 2.
c) The table range is incorrectly programmed.
Program the table range for the cailibrated range of the transducer.
d) The input is not configured for 4–20mA.
Configure the zone for 4–20mA. Refer to Chapter 4.
e) Multiple devices connected in loop.
The 1800’s zone is single-ended and terminates to ground. Because of this, the 1800 must be the last device in the loop, and in some cases the ONLY device. For certain installations, it may be necessary to use a signal isolator.
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