CEM3 Reporting Over-voltage, Under-voltage, and Frequency Errors

Symptoms

The CEM3 is reporting frequency and/or phase voltage errors
Errors may include conflicting information, i.e. Phase voltage high, Phase voltage low, Phase no voltage

Explanation of Issue

For errors with a single phase problem, such as Phase C voltage low, a phase op-amp, diode, resistor, or opto-isolator may have failed.

For errors with conflicting information, the DSP may have a problem. Either the DSP is not loading the firmware, or the DSP has been damaged. Phase A might be missing between the mains line and the DSP, suggesting an op-amp, resistor, opto-isolator, and/or diode failure

This typically cannot be fixed in the field

Fix/Solution

If all phases read OK going into the rack test OK, please contact ETC Technical Services to begin the RMA process