Munters T3 SNS ERR Error Code
Error in temperature sensor 3
Source: hvac/munters/0d9d3440__smart-c__mntr-smart-c-d-iom.pdf
What does Munters T3 SNS ERR mean?
On a Munters Smart C/D climate controller, T3 SNS ERR means a fault has been detected in temperature sensor 3. The manual states this sensor is either out of order, disconnected, or shorted, so the controller cannot obtain a valid temperature from that input. The alarm shows on the main screen, alternating with the normal display.
Symptoms
- T3 SNS ERR alarm shown on the main screen
- Temperature from sensor 3 reads as invalid or missing
- Alarm relay activates and the alarm repeats until cleared
- Control functions relying on sensor 3 behave abnormally
Common causes
- Temperature sensor 3 is out of order
- Temperature sensor 3 is disconnected
- Temperature sensor 3 wiring is shorted
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Diagnostic steps
Acknowledge the alarm
Press OK on the main menu to reset the alarm relay; the manual notes the message stays until the fault is resolved.
Check the sensor 3 connection
Inspect temperature sensor 3 wiring for a disconnected lead, a cause noted in the manual.
Inspect the wiring for a short
Check the sensor 3 cable for a short circuit, listed as a possible reason in the manual.
Replace a failed sensor
If sensor 3 is out of order, fit a working temperature sensor on that input.
Disable the alarm only if the sensor is removed deliberately
Per the manual, a deliberately removed sensor's error alarm can be disabled via the Calibration menu.
When to call a professional
The Smart C/D manual cautions that if a hardware problem arises you should not open the box and should contact an authorized electrician. Call a qualified technician if the alarm remains after checking the connection, if you are not equipped to work safely inside a mains-powered controller, or if sensor replacement and recalibration exceed your experience.
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