The Electrical Contractor Network

ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

Books, Tools and Test Equipment for Electrical and Construction Trades

Register Now!

Register Now!

We want your input!

Featured:
   

2017 NEC and Related
2017 NEC
Now Available!

   
Recent Posts
Sprinklered equipment 26-008
by bigpapa
Today at 04:24 PM
On Delay Relay with Auto Reset
by Potseal
Yesterday at 09:59 AM
Wow, that was close!
by jraef
11/28/16 07:06 PM
Earthquake in New Zeeland
by RODALCO
11/27/16 11:25 PM
Calling all Non-US members!! (Non-US only)
by Tjia1981
11/27/16 06:33 AM
New in the Gallery:
12.5A through 0.75mm˛ flex (just out of curiosity)
Shout Box

Top Posters (30 Days)
gfretwell 15
HotLine1 10
Texas_Ranger 8
Trumpy 8
sparkyinak 7
Who's Online
0 registered (), 218 Guests and 4 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#196845 - 10/29/10 02:19 PM another fire hazard panel
Niko Offline
Member

Registered: 08/17/06
Posts: 358
Loc: Campbell, CA
My client had a short on a GE 15A OCPD and it didn't trip. Today I tested that circuit breaker with a 30Amp load and it wouldn't trip.
Is GE another fire hazard panel? Have any of you had the same trouble?

http://www.circuitbreakerservice.com/images/THQP120.jpg
_________________________
Be kind to your neighbor, he knows where you live


Top
Work Gear for Electricians and the Trades

Work Gear for Electricians and the Trades
Work Gear for Electricians and the Trades
Arc Flash Clothing, Gloves, KneePads, Tool Belts, Pouches, Tool Carriers, etc. etc....

#196846 - 10/29/10 02:27 PM Re: another fire hazard panel [Re: Niko]
renosteinke Offline
Cat Servant
Member

Registered: 01/22/05
Posts: 5305
Loc: Blue Collar Country
There are, believe it or not, different types of 'shorts.' Sometimes there is enough impedance - arcing is a high-impedance type of fault - that a breaker may respond slowly.

As for the 30-amp load, the question is: how long was the load applied? Breakers trip faster the greater the overcurrent condition.

Still, everything in this world shows variations in quality, and wear out / break down with time. Maybe you have a bad breaker - but that's no reason to suspect an entire product line.

Top
#196848 - 10/29/10 04:04 PM Re: another fire hazard panel [Re: renosteinke]
mikesh Offline
Member

Registered: 06/07/06
Posts: 614
Loc: Victoria, BC, Canada
A 15 amp circuit breaker is tripping on a time curve until around 38 amps where it starts to react in it's instantaneous range.
As a rule of thumb you need 6 to 8 times the rated current to trip any circuit breaker and most fuses in less than 8 cycles (instantaneous trip)
A 15 amp breaker will carry 135% or its rating for around an hour or about 20 amps.
So how long did you apply a %100 overload?

Then there are loose set screws, loose bonding terminals, and other bad connections that can add impedance to the fault path which can create sustained faults in the many minutes range where good connections might trip a breaker faster. Imagine your fault path is the EMT and several set screws are not tightened or worse the pipe separates. 8 ohms is enough resistance to allow a 15 amp breaker to feed a fault as if it was a load and the breaker never trips. Can you start a fire with 1800 watts? Sorry I will stop now as it is becoming a lecture.

Top
#196850 - 10/29/10 04:38 PM Re: another fire hazard panel [Re: mikesh]
HotLine1 Offline

Member

Registered: 04/03/02
Posts: 6804
Loc: Brick, NJ USA
Years back I had heating issues with a batch of GE 'Thin' single pole CBs. They originated in Mexico, and could have been the first batch from a GE plant relocation.

Returning the batch for replacements was no hassle at the then local GE Supply. Replacements were USA origin, at my insistance.

As Mikesh said, other issues could lead to a non, or long trip.
_________________________
John

Top
#196854 - 10/29/10 04:57 PM Re: another fire hazard panel [Re: renosteinke]
Niko Offline
Member

Registered: 08/17/06
Posts: 358
Loc: Campbell, CA
Quote:
As for the 30-amp load, the question is: how long was the load applied? Breakers trip faster the greater the overcurrent condition.


I left it on for about a minute.

Top
#196856 - 10/29/10 05:07 PM Re: another fire hazard panel [Re: Niko]
HotLine1 Offline

Member

Registered: 04/03/02
Posts: 6804
Loc: Brick, NJ USA
Niko:
IMHO, a minute was not long enough. If you want to spend some time, contact a GE company/factory rep and inquire IF they have any interest in testing or disecting that baby.

If it's a fairly new CB they may have a vested interest in checking it out.
_________________________
John

Top
#196860 - 10/29/10 05:16 PM Re: another fire hazard panel [Re: HotLine1]
Niko Offline
Member

Registered: 08/17/06
Posts: 358
Loc: Campbell, CA
The place is about 40 years old and so are the breakers.
_________________________
Be kind to your neighbor, he knows where you live


Top



ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals