Insulation breakdown
Insulation breakdown
(OP)
Hi,
Any reason about the cause of failure? The unit is a 250 k W compression chiller.
Thanks
Guardiano
Any reason about the cause of failure? The unit is a 250 k W compression chiller.
Thanks
Guardiano





RE: Insulation breakdown
Is this running on an ungrounded system?
Have you had any electrical storms in the area?
Bill
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"Why not the best?"
Jimmy Carter
RE: Insulation breakdown
Suspects in general would include contamination and (as Bill suggests) steep front voltage spikes from some external origin.
No contamination is visually evident, was the winding cleaned?
Voltage spike scenario gets more likely if the failed coil is the line end coil or an electrically-adjacent coil in the circuit.
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(2B)+(2B)' ?
RE: Insulation breakdown
Was the inside of the stator polished with a buffing wheel?
Was this done shortly before the failure?
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Insulation breakdown
Waross, the polished area on the stator is from origin. I am suspecting repeated starts, due to reduced load, but I don't have any records to support this statement. The compressor is star/delta started.
Guardiano
RE: Insulation breakdown
If the motor was maintenanced could be possible that the winding was contacted by the rotor once the rotor was installed again.
Regards
Carlos