Meggar testing

[hurricanemark]

I have a customer whose house was hit by lightning. It was a major hit. They feel some wiring in the walls may be damaged. I feel the only way to tell is by Meggar testing. What is the correct procedure for testing residential circuits?

 

[ramsy]

Except for checking the Switchlegs & 3way travelers, wouldn't this procedure include shutting off main breaker, shutting off all AC / motor / light switches and unplugging all wallwarts, before Meggering across the breaker poles to neutral, ground, then pole to pole.

 

[electricalperson]

disconnect all loads including fixtures and GFCI's and dimmers. no electronic devices on the circuit. disconnect all conductors from the panel including neutral and ground, attach the red wire from the megger to ground. also called positive or earth. then use the black wire also called negative or line to each conductor being tested, megger hot to ground neutral to ground and neutral to neutral. the romex or bx cable can be meggered at 1000v. make sure everything is unplugged. if a tv or other electronic device including dimmers,computers and gfci's will be destroyed by a megger test and you also will blow lamps

 

[Sierrasparky]

also make sure you de-energize the capacitence after you test. :roll:
You can get quite a shock or blow a connected device :-?

 

[brian john]

Documentation.

 

[mdshunk]

Documentation.

Right. Not only for the report, but to keep your own head straight. I mostly just use a tablet. I run through with a regular ohm meter first, just to see if there are any missed loads or hard shorts, and record any problems on the note pad. Square these things away first before you hit it with a megger.