Dielectric testing

[craigwithak]

I have done some research but am still confused as to how to meet the code requirement, 550.17, 2005 NEC applies to the work I am doing. I don't understand which test , Hipot, Megger, or other will fit the application. I am installing a 100 amp panel 208/240 power and 3 to 4, 15 to 20 amp branch circuits (lights and receptacles). Also a 1 ton HVAC unit with a 2 pole 30 amp breaker. I am using M/C cable 12-2 w/ground, and #8 stranded wire on the HVAC. I am hoping to not have to spend 1000's of dollars on test equipment. Any input would be appreciated. Thanks

 

[zog]

It will just be a megger test, if this is a rare thing for you hire a testing company job like that will only run a few hundred bucks, if you will need to do this often go buy a handheld 1000V megger and download "A stich in time" from the megger website.

 

[mdshunk]

If you don't often have a need to do such work, it might be easier to hire it done. I say that in this case for several reasons. One, when you're doing legally required testing, it's not the time for learning. Two, you may well need the instruments that do such testing to have a recent verifiable calibration, which adds to the cost of the instrument if you're buying one. As to the particular instrument, anything that will get you 900 or 1080 volts will do the trick. If you do this test yourself, you might have to repeat it on each leg if you have 3-ways. Second test would be with at least one 3-way of each pair toggled the other direction so that each traveler is properly tested.

Do you manufacture mobile homes, or are you just adding circuits to one?

I also find it odd that the code calls this a dielectric test, which it truly is, but that term in industry generally means testing with 5,000 volts and higher.

 

[craigwithak]

I am building portable office space out of steel shipping containers. As I stated the electrical is very basic, but we just happen to fall under a couple of different NEC regulations so one of the states we are getting inspections from has required the test. I will be purchasing A megger to fulfill the requirements. There are no three ways. Thanks for the input