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Bad ism

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I would scope the 3 phase input voltage waveform and look for transients and other potential issues on the line, also check the control voltage is within specified parameters and components are not overheating.

I'm almost positive that it has a bad ISM. Voltage on the CVC display are all out of wack. "Actual Line Voltage" is giving a reading of 528 Volts. Line Voltage Phase1 602v, phase 2- 524v, phase 3 458 volts. I know that's wrong because I have checked it on the panel and all voltages and phase are correct there. I keep getting "Phase Reversal Trip", Line Voltage Imbalance", 1M Aux Contact Faul". Different alarms.

What is yours doing?

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What the ISM the problem? I'm having similar issues.

You could even have something as simple as a loose connection on the communication wiring connecting all the control boards, or corrosion on a pin connecting a sensor to a board. In my experience I have noticed Carrier chillers to be very prone to nuisance faults that do not actually exist. I would check every connection on every board before replacing components. I wish you luck.

Most likley ISM

Im sure you already fixed this but i have replaced 2 isms for the same reason in the past 5 years on the same 19xrv. Just thought id post for others

Most likely the ISM

I don't see how to edit? Oops.

Me thinks you need to remove your pricing per the rules.

Carrier 19XRV "high line voltage" alarm. ISM bad?

Trouble shooting a customers 19XRV. Prestart failure on High line voltage. Panel shows 200-1000v jumps around. Incoming is rock steady at 480v.
Trouble shot panel with power off, now alarms with reverse phase?
Power and phasing is normal, anyone seen this? I'm guessing the ISM board. But that is a $2100 guess, Any help is appreciated

Greg