ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Top Posters(30 Days)
twh 10
Recent Posts
Any UL 508 experts out there?
by sparkyinak. 05/21/17 08:57 PM
Heat pump conundrum
by sparkyinak. 05/21/17 08:49 PM
Interesting week
by HotLine1. 05/20/17 11:57 AM
Electrical Pricing Guide
by ElectricianBud. 05/18/17 12:17 PM
New in the Gallery:
SE cable question
Popular Topics(Views)
236,237 Are you busy
171,028 Re: Forum
164,135 Need opinion
Who's Online Now
0 registered members (), 45 guests, and 12 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
#21038 - 01/26/03 03:00 PM Testing damaged circuits  
jes  Offline
Member
Joined: Jul 2002
Posts: 103
CT
In cases where you are called to fire and/or water damage cases what testing do you typically do to assure yourself that circuits which are not destroyed are still serviceable? If megging what value is considered good?? WHat is your damage criteria for removing equipment completely and starting over?? Anyone had callbacks where there were problems down the road on reused circuits/equipment??


Work Gear for Electricians and the Trades

#21039 - 01/26/03 09:19 PM Re: Testing damaged circuits  
harold endean  Offline
Member
Joined: Feb 2002
Posts: 2,233
Boonton, NJ
You might be able to get a megger and test all of the remaining circuitry. Just a thought.


#21040 - 01/27/03 07:31 PM Re: Testing damaged circuits  
jes  Offline
Member
Joined: Jul 2002
Posts: 103
CT
Hi Harold,
What value of resistance would you consider 'good'?? How would you treat the problem from an inspector's standpoint with the EC??


#21041 - 01/27/03 07:46 PM Re: Testing damaged circuits  
golf junkie  Offline
Member
Joined: Apr 2001
Posts: 507
York, NE
Jes,

FWIW....I would like to see >10meg , but would probably accept anything over 1 meg.

GJ


#21042 - 01/28/03 12:54 AM Re: Testing damaged circuits  
ThinkGood  Offline
Member
Joined: Aug 2002
Posts: 1,081
Milwaukee, WI
Pardon my ignorance, but does a "megger" place voltages on the circuit that is tested?

Wouldn't that be dangerous in a situation where there is damage, and one is not certain if insulation is bare, etc?


#21043 - 01/28/03 10:10 AM Re: Testing damaged circuits  
pauluk  Offline
Member
Joined: Aug 2001
Posts: 7,520
Norfolk, England
Yes, a megger places voltage on the system. In England we typically test normal 240/415V systems at 500V DC.

It's a high voltage, but supplied through a high impedance so that the current is limited, typically 3 or 4mA into a dead short. The 500V level is achieved only if the circuit insulation is good.

I'd be looking for a value of at least 1 meg., although I'd rather let the wiring dry out some more and get it higher before re-applying power.



Member Spotlight
Posts: 165
Joined: March 2007
Show All Member Profiles 
Featured:

2017 NEC and Related
2017 NEC
Now Available!

Shout Box
Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.012s Queries: 14 (0.003s) Memory: 0.7748 MB (Peak: 0.9221 MB) Zlib enabled. Server Time: 2017-05-23 10:49:10 UTC