Checking Residential after Lighting Strike

[wmeek]

Had customer call and say that lighting hit her house over the weekend. Have not been there yet to check any damages. She says that a few outlets and lighting are out. Was just checking to see if anyone had a checklist for this type of service call. I have never been thru a lighting strike process before. If anyone has an input as what steps to take would be greatly be appreciated.

Thanks

 

[ItsHot]

megger

megger

Some would suggest, including "megger Marc" to meg everything! Which according to how much of a hit the house took is probably a good idea, but a very long process. I would at the least, inspect the panel, look for burned conductors, check terminations. As for the non-working receptacles, there will be something burned out! Usually the receptacle, but possibly the conductors also.

 

[mdshunk]

Visually inspect and confirm continuity of grounding electrode conductors and their attendant termination at the grounding electrode(s).

Visually inspect the panel. Confirm that all the electronic devices (dimmers, GFCI's, chime transformer, furnace, air conditioner, etc) work or not.

Megger all branch circuit conductors and repair as necessary.

 

[wmeek]

Do not have a megger. I will definetly check the Panel and over areas for any signs of wire that have got hot. Hopefully the damage is minimal. If it looks like there is extensive damage I will get a megger and go thru the process.

 

[ItsHot]

easy money!

easy money!

Visually inspect and confirm continuity of grounding electrode conductors and their attendant termination at the grounding electrode(s).

Visually inspect the panel. Confirm that all the electronic devices (dimmers, GFCI's, chime transformer, furnace, air conditioner, etc) work or not.

Megger all branch circuit conductors and repair as necessary.

Easy money!:smile:

 

[wmeek]

Hey Marc

When you say meg all branch circuits, can you do it from the panel with everything (equipment) disconnected from circuit. Or do I need to break all joints and do them individually

 

[mdshunk]

If it looks like there is extensive damage I will get a megger and go thru the process.

That's sort of backwards thinking, but if you don't own a megger, I can understand why you might think that way. The megger sorts out all the damage that you can't see. I have been on lightning damage calls where the damage was highly visible (blew the panel up, etc), were the conductors megged fine, for the most part. On the other hand, I've been on calls where the place was visually okay (aside from a few non-working televisions, etc) where the conductors megged out aweful and a lot of rewiring was necessary. I guess what I'm trying to say is that what you see or don't see with your eyes does not necessarily relate to what sort of insulation resistance measurements you wil obtain with the megger. If you asked me, I'd say that if you do nothing else on a lightning damage call, you need to at least megger. There's really no other way to determine if the conductors and cables are fit to place back into service.

 

[peter d]

Hey Marc

When you say meg all branch circuits, can you do it from the panel with everything (equipment) disconnected from circuit. Or do I need to break all joints and do them individually

I was wondering the same thing. And also, can you do it with non-electronic devices (switches, outlets) installed?

 

[mdshunk]

When you say meg all branch circuits, can you do it from the panel with everything (equipment) disconnected from circuit. Or do I need to break all joints and do them individually

Unplug everything, take out all the light bulbs, jumper out any GFCI's and dimmers, disconnect chime transformer and other connected loads (ballasts, attic fan, furnace, well pump, etc). The actual megger checks are pretty easy, but doing the setup work to start doing the test is what takes the time.

 

[mdshunk]

I was wondering the same thing. And also, can you do it with non-electronic devices (switches, outlets) installed?

Yeah. You actually want these things in the circuit, if at all possible. Leave all the switches in the "on" position to check the maximum amount of installed cable. The only devices you need to take out are the electronic one's like dimmers and GFCI's. Oh, lighted switches, I guess.

 

[Mule]

Ha...we had one of these calls last week...Fried all of the GFI's, took out the phone wiring and phones and ma-bell box, motion light, stereo, PC, and best of all was the kitchen island recept !!! some knuckle head ran bare THHN embeded in the slab out to the island.....It arc'd to the moisture in the slab, blew a big chunk of concrete out including 12x12 square tile. Also found a arc place on the bare #4 in the main panel....

Owner had us sign papers for all item for the insurance adjuster.........

 

[wmeek]

Hey Marc

What type of megger do you use. Sounds like I need one to properly check out this job. Also , where can i finfd the correct insulation readings I would be looking for.