Hi James.
The fact that the comps are McQuay is irrelevant.
Basically all three conditions you describe can be attributed to Motor burnouts and fluctuating voltages.
In some of the more remote sites we look after.
Supply voltage drops have been a huge problem.
You won't get the supply company to admit issues or indeed the site sometimes.
We got to the bottom of similar issues at one site by fitting power monitoring meters to each of the compressor motor supplies.
Which resulted eventually on a new site transformer being installed,
But more importantly it proved the fault was not with the equipment.
And the liability was shifted away from us.
You would be amazed at some of the recorded Voltage drops ( Which will cook compressor motor windings.)
Grizzly