Emerson Rosemount 975 - Troubleshooting; LED Off, Fault Relay Open, 0-20 mA 0 mA; LED Flashes Yellow, Fault Relay Open, 0-20 mA 1 mA; LED Flashes Yellow, Relay Open, 0-20 mA 2 mA

6 Troubleshooting
6.1 Light-emitting diode (LED) is off, fault relay is
open, 0-20 mA shows 0 mA, analog voltage
output is 0 V
Potential cause
No power to the unit.
Recommended actions
1. Check that the operating voltage is correct, according to Electrical specifications.
2. Check power polarity.
3. Check the terminal wiring.
6.2 Light-emitting diode (LED) flashes yellow at 4
Hz, fault relay is open, 0-20 mA shows 1 mA
Potential cause
Low voltage.
Recommended action
Check that the operating voltage is correct, according to Electrical specifications.
Potential cause
Faulty detector.
Recommended action
Re-power the detector.
6.3
Light-emitting diode (LED) flashes yellow at 4
Hz, relay is open, 0-20 mA shows 2 mA
Potential cause
Built-in test (BIT) fault.
Recommended action
Ensure the detector window and reflector mirror are clean.
Potential cause
Faulty detector.
Recommended action
Re-power the detector.
Manual Troubleshooting
00809-1400-4975 September2023
Rosemount 975 31