Breaker care?


  #1  
Old 09-26-02, 07:41 PM
C
Member
Thread Starter
Join Date: Dec 2001
Location: middleboro,ma
Posts: 282
Upvotes: 0
Received 0 Upvotes on 0 Posts
Question Breaker care?

Hi,
I own a two family home in Mass,wich has two 100 amp circut breaker panels,wich was recently all replaced.
Somebody said you should flip all the breakers off,then on every year?Is this true,does it help?Thanks
 
  #2  
Old 09-26-02, 08:00 PM
S
Member
Join Date: Jun 2002
Location: Brethren, Mi
Posts: 1,564
Upvotes: 0
Received 0 Upvotes on 0 Posts
Thats a new one on me. It wouldnt hurt any thing I guess but have never heard of it.
 
  #3  
Old 09-27-02, 06:04 AM
HandyRon's Avatar
Member
Join Date: Dec 2001
Location: New York
Posts: 1,287
Upvotes: 0
Received 0 Upvotes on 0 Posts
The following is an excerpt from the
National Fire Protection Assoc.
70B Recommended Practice for Electrical Equipment Maintenance
1998 Edition
Chapter 11 Molded-Case Circuit-Breaker Power Panels
11-11 Mechanical Mechanism Exercise.
"Devices with moving parts require periodic checkups. A molded-case circuit breaker is no exception. It is not unusual for a molded-case circuit breaker to be in service for extended periods and never be called on to perform its overload- or short-circuit-tripping functions. Manual operation of the circuit breaker will help keep the contacts clean, but does not exercise the tripping mechanism. Although manual operations will exercise the breaker mechanism, none of the mechanical linkages in the tripping mechanisms will be moved with this exercise. Some circuit breakers have push-to-trip buttons that should be manually operated in order to exercise the tripping mechanism linkages. "

Yearly sounds ok.
 
  #4  
Old 09-27-02, 09:34 AM
Sparksone42
Visiting Guest
Posts: n/a
Ron,

Maybe I am misinterpreting what you wrote in that excerpt but, the way I read it, turning the breakers on and off is not worth the effort, as it will not excersize the tripping mechanism.

This is the first reference that I have ever heard of in regard to breakers and their maintainence. I would say after reading what has been written to leave them alone. It has been my experience that the more times a breaker is turned on and off ie: used as a switch the less effective the breaker will be.

I do have a customer that, due to the nature of their business being a "liveaboard yacht storage facility", boatowners and the crews will always turn the breakers off before removing a shore power cord. This is as it should be for safety but, as a result I am constantly out there replacing breakers that either fail or get weak and won't hold the current the boats draw.

Just my opinion
 
  #5  
Old 09-27-02, 05:07 PM
HandyRon's Avatar
Member
Join Date: Dec 2001
Location: New York
Posts: 1,287
Upvotes: 0
Received 0 Upvotes on 0 Posts
The two aspects of the quoted NFPA sections that I wanted to bring out were:
"Manual operation of the circuit breaker will help keep the contacts clean"
"manual operations will exercise the breaker mechanism"

Your choice as to how you interprete those items.
 
  #6  
Old 09-27-02, 06:18 PM
MTgets
Visiting Guest
Posts: n/a
Hmmmm, this is a interesting one....

I can see both sides of the issue but would tend to slightly side with the leave them alone camp.
Reason being, the on/off action does not work the trip mechanism, this is proven by the wives tale of people taping the handle to the on position to keep the circuit live during a long current draw period, CANT DO IT!!! the internal mech. doesnt care how hard you try if it senses a overload it will trip!! Nothing to do with the handle operation.

Also if the breaker is not rated to be used as a switch I believe (somehow?) it is detrimental to the integrity of that breaker? Not positive anyone else ever hear this, why else would they make SWD rated breakers then?

Also NFPA says it keeps the contacts clean?? They must have never had to replace contacts in a motor starter. haha Under load it must create a arc, which pits the metal and creates carbon buildup, which leads to dirty and ineffective contacts.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: