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HOW TO DO 350KW GENERATOR MEGGER TEST?? 2

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hafeez777

Electrical
Joined
Feb 16, 2016
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2
Location
CA
Hello guys I'm new in this forum hope some senior members can help me.my question is here how can I measure 350kw marine generator insulation test by megger to measure all electrical winding resistance ,hope some one can help me .
thank you in advance
 
Here is a very good manual with instructions on testing a generator, even if your generator is a different make the procedures and limits are reasonable for most any generator in your size range.

MikeL
 
 http://files.engineering.com/getfile.aspx?folder=832316cb-f437-410a-8b81-39d379283b8c&file=TD_FAULT_MAN.GB_JULY_2009_GB.pdf
Marine environment = Automatic ally high humidity, near constant close association with water and humidty.

Be VERY careful how and when you interpret low resistance to mean = bad insulation or a failed generator. Trying checking that the surface, the generator, the surrounding enclosures are closed, really are dry for many hours before, that humidity is as low as possible (fogs happen!), and that condensation is not the source of low resistance reading problems.

However, do not excuse every low reading with "humidity again" either!
 
Following the manual Mike posted will lead you in the right direction. You need to be sure that each winding is isolated before testing. Voltage regulator and control panel sensing leads need to be disconnected, as well as any neutral grounding conductors. Also disconnect rotating windings from rectifier bridge. If you post your results here we can help interpret them. Make sure to record winding temp and relative humidity.
 
Thank you guys Mikel , Racookpe1978 and IBRCAN for useful tips. appreciated
 
You need to connect the winding that you do not check directly to the ground
for your safety
 
As far as i my knowledge, megger is used to measure insulation resistance not winding resistance. Megger is used to measusure insulation resistance of generator. Connect one point to generator output terminal and other to external metal part of generator and then start megger.
 
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