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3a) Defective Analog Input Module For Channel
4a) RTD (Resistive Temperature Device) Wiring To The “EXHAUST” 4 to 20 milliamphere (4 to 20
mA) Transmitter
5a) Circuit Wiring To the Analog Input Module
b)
POSSIBLE SOLUTIONS;
1b) With the control voltage “OFF.”
The exhaust RTD (Resistive Temperature Device) probe can be quickly checked, by locating its
labeled disconnect in the right hand wire which is located on the main electrical enclosure panel.
Disconnect this plug and measure the resistance of the two wires coming from the RTD; it
should be
in the 100 ohm (100
Ω
) range.
•
If resistance is within range, wiring and RTD are OK.
•
If the resistance is infinite (no measurements), or zero ohms (0
Ω
) , go directly to the intake RTD
(Resistive Temperature Device)
disconnect box and measure the RTD’s resistance directly.
•
If the RTD resistance measurements is acceptable, check circuit wiring.
•
If the RTD resistance measurements is not acceptable; replace RTD and re-test
2b) Defective 24 Volt DC Power Supply
With the control voltage “ON,” check that 100 volts AC is applied to the device’s AC input.
•
If no voltage check fuse #8, and wiring and re-test.
Check that the device’s DC output indicator is “ON.”
•
If “OFF”, this indicates that there is no 24 volts DC output
Disconnect the output voltage wires connected to the power supply and notice if the L.E.D. (light
emitting diode) indicator responds
•
If the power supply responds to the disconnection, there is a problem with the driven load and not
the power supply itself
•
Check
ALL
loads and re-test
Check that the device’s output voltage is 24 volts DC.
•
If not, adjust it
3. DEFECTIVE ANALOG INPUT MODULE or CHANNEL
Replace Analog Input Module
