Generator Megger Testing
Generator Megger Testing
(OP)
I am installing a new 480 Volt, 1825 KW standby generator (its predecessor suffered a generator bearing failure during an extended run). The new unit sat outside at the dealer for a couple of weeks in almost constant rain/wind and high humidity. It was wrapped in plastic sheeting for part of the time. It was megger tested upon arrival at the dealership, and tested OK.
The unit has since been delivered to our customer's site (they pay us to operate and maintain their standby system, and it is considered of critical importance to them) and set back into the enclosure. The phase cabling has been terminated. We are asking the vendor to repeat the megger test prior to operating the engine since the unit sat outside and was transported since the original test, just as a safety precaution.
My vendor's engineer insists that this is a complete waste of time since it was tested upon arrival at their shop. In my opinion, it is a good final check to assure that no moisture remains in the windings, and that no damage was done during transport and installation. It is quick, cheap and easy to repeat and may also show problems with sensing instruments and/or phase cabling between the switchgear and the engine.
Am I out of line insisting that this test be repeated? Is their really nothing to be gained?
Just looking for opinions.
Thanks
The unit has since been delivered to our customer's site (they pay us to operate and maintain their standby system, and it is considered of critical importance to them) and set back into the enclosure. The phase cabling has been terminated. We are asking the vendor to repeat the megger test prior to operating the engine since the unit sat outside and was transported since the original test, just as a safety precaution.
My vendor's engineer insists that this is a complete waste of time since it was tested upon arrival at their shop. In my opinion, it is a good final check to assure that no moisture remains in the windings, and that no damage was done during transport and installation. It is quick, cheap and easy to repeat and may also show problems with sensing instruments and/or phase cabling between the switchgear and the engine.
Am I out of line insisting that this test be repeated? Is their really nothing to be gained?
Just looking for opinions.
Thanks






RE: Generator Megger Testing
How else do you know nothing was damaged during installation, or some part of the installation was not performed correctly?
Previous tests, including factory tests, are not applicable.
RE: Generator Megger Testing
RE: Generator Megger Testing
The tests you are proposing sound entirely reasonable. I assume the vendor is providing a warranty against any failure due to poor storage? You might consider making that a condition of not rejecting the unit.
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Sometimes I only open my mouth to swap feet...
RE: Generator Megger Testing
Thanks for the replies. I apprceciate your feedback!
RE: Generator Megger Testing
Tell him to megger it or get it off your site - cordially, of course.
And DanDel is right, megger is the bare minimum test. There are a whole host of other's you should be considering.
Regards,
JB
RE: Generator Megger Testing
RE: Generator Megger Testing
respectfully
RE: Generator Megger Testing
RE: Generator Megger Testing
RE: Generator Megger Testing