Troubleshooting – SOR Single Point Ultrasonic Level Switch User Manual
Page 16
16/20
Form 771 (08.13) ©SOR Inc.
Troubleshooting
Symptom/Problem Possible Cause
Corrective Action
No current in the loop
No LEDs lit.
1. Power supply turned off.
2. Improperly wired terminal block TB1.
3. Broken power supply wire.
1. Check power supply source.
2. Check terminal block wiring per
(page 5)
3. Check loop wire integrity.
Current 5 or 19 mA.
No LEDs lit or both
LEDs lit.
1. Sensor lead unplugged.
2. Sensor integrity is compromised.
3. Remote Self-Test activated.
1. Check sensor cable connections.
2. Replace the sensor.
3. Check dry contact & TB2 wiring.
Current stays at 8 mA
when liquid is in the
gap.
Yellow LED remains lit.
1. Process is highly aerated liquid.
2. There is no liquid in the gap.
3. Remote cable length has been changed*.
4. Circuit integrity is compromised.
1. Install baffle or stilling well, or use
a 651K9 RF Point Level Control.
2. Unit is operting properly.
3. Replace circuit board.
4. Replace circuit board.
Current stays at 16 mA
when the gap is empty
Red LED remains lit.
1. Process is clogging the sensor.
2. There is liquid in the gap.
3. Remote cable length has been changed*.
4. Circuit integrity is compromised.
1. Clean the sensor.
2. Unit is operating properly.
3. Replace circuit board.
4. Replace circuit board.
Current is greater than
20 mA.
1. Incorrectly wired circuit.
2. Circuit integrity is compromised.
1. Check current loop wiring per
(page 5)
2. Replace circuit board.
Remote Self-Test does
not switch to 5 or 19 mA.
1. Open signal wire.
2. Wires hooked to the wrong terminal block.
1. Check twisted pair wire integrity.
2. Verify dry contact wired to TB2.
Current intermittently
switching to 5 or 19 mA.
1. Improperly grounded shield of TB2
twisted pair.
1. Ground one end only of the twisted
pair shield.
*Circuit boards for remote units are tuned at the factory for optimum performance with specified
cable length. If the remote cable length is changed, circuit operation will be adversely affected.
NOTE: Agency certifi ed units, (FM, CSA, IEC) must be returned to SOR for repairs.