[dfishing]

So we had a lighting strike at our house and I have been checking into how to check the insulation of the wiring, I see the ins company has for a test with a megohmmeter so I been looking into doing this myself but really can't find any clear cut instructions. So in order to test my house wiring it looks like I need to remove power from the circuit and any dimmers, GFI's, light bulbs and any thing that is plugged in. so if I remove a GFI do I just connect the wires with a wire nut temp so I could test the entire circuit is that how I do it? And I also have some other wires to check . Think it is cat v wire that is for a phone and dsl signal that I want to check from what I have found looks like you would use a 250v or 300v setting on the meter to check all my house wiring and the cat v stuff? Also not sure which megohmmeter to buy how good of one do I need to get to get a reliable reading. Also just to make sure I understand what I'm doing I think this is how It works so when I connect to the wire and charge it it will send out the high voltage low current dc and if there is a problem with the insulation of the wire it will leak back into the ground and be picked up by the meter sound right? Like I asked what brand and which meter to buy?

[hfcarson]

Do internet searches for "megger" and "megohm testing"... you will have some reading to do as this is not a simple subject. Read up until you get a good understanding of what you should see on the megger... (mine is from Amprobe)... when the conductor insulation is good, bad or failing.
I've done this professionally a few times so after you learn the test it's not very difficult.

What damage was done by the lightning?

[ebaines]

I would strongly urge that you leave this to the pros, because if you make a mistake you may injure yourself or fry an applicance that hasn't been disconnected. The insulation resistance test sets that I've seen typcially use alligator clips to connect to the cable under test. You test one section of cable at a time. You disconnect the wires at both ends of the cable from whatever it's connected to (circuit breaker, outlet, switch, splice to other cables, etc), insulate the bare wires at one end of the cable with wire nuts so they don't accidentally touch a grounded surface, then apply the tester at the other end of the cable. You test between the hot lead to neutral and hot to ground and see what the readings are.

Testing communications wiring is easier - just make sure all phones, PCs, printers, modems etc are disconnected, and also that the connection at the Network Interface Device to the phone company line is unplugged. Don't test any higher than 300V because it could set off the TelCo protectors in the NID.

[hfcarson]

Yes, please heed the advice from ebaines...
This test does need to be done carefully with an understanding of the damage that can be caused by any application of a high voltage...

[dfishing]

Thanks well damage was mostly to things plugged in computers,tvs, surge protects don't work anymore hve two light switches with black on them and on the phone line it blew the dsl fliter into two pieces and now the switch board that splits the phone signal doesn't work two black burns on back of it it kicked out 6 breakers and every gfi in the house. Physically looking at the wires they all look fine except maybe the phone line is questionable.

[hfcarson]

Wow! So maybe doing or having a megger test would be a good idea...
Good luck and be safe,
HC