Resi breakers, testing of

Yoyizit · 07-09-2010, 06:59 PM

Questions to a CB manuf.:
Is there a recommended replacement interval for resi. CBs?

Is there any problem with periodically testing them by loading them to 2x or 3x rated current, measuring trip time and then comparing this value to the trip curve?

A: There are no recommended time frames to replace residential breakers, as far as testing we test per UL 489, there is no additional field testing required, however if you want to periodically test the overload there is no problem doing so.

nap · 07-09-2010, 07:27 PM

UL does not deal with field tests. UL tests are lab testings.

as to UL not limiting field tests: of course not, That is not what they do but I do know that some, if not all manufacturers recommend 2 things with breakers:

they are exercised regularly (simply switched on and off several times) to prevent them from becoming stiff

if they are exposed to a ground fault trip (magnetic trip), it is recommended they be replaced. While I suspect it is mainly as a defense to a liability claim, in all reality, a breaker can be exposed to possibly thousands of amps any time there is such an overload and that amount of current can cause unseen damage.
-------------------------------

there is no design life I am aware of or ever been told of. As such, there is no recommended replacement interval I have ever heard of.

Quote:

Is there any problem with periodically testing them by loading them to 2x or 3x rated current, measuring trip time and then comparing this value to the trip curve?

Not that I am aware of but one needs to understand the trip curve published is based on a lab test. Variable temps and other conditions in the field can alter the time/current/trip relationship.

frenchelectrican · 07-09-2010, 10:47 PM

Most resdentail breakers as far as I know there really no life limit on them due there is a bit of variations what it will be used etc .,

But on very large commercal and Industrail breaker yeah there is the Numbers of cycles we have go thru before it will be either replace or rebuilt however if got very hevey bolt fault it pretty much automatic replacement for new breaker and megger that affected circuit for any hidden damage especailly that is true with 480 volts 60 HZ { 415 V 50 HZ as well } and above.

However basically just exersice the breaker every year by turn it on and off I know you may hate to reset the clock and reboot the computer but that is the good safe way to make sure everything is up to the stuff.

Merci.
Marc

Scuba_Dave · 07-09-2010, 11:02 PM

I've known several commercial properties that used the breakers to turn the lights off & on every day
I guess that would exercise them...maybe too much ?
Only about 700 flips a year

nap · 07-09-2010, 11:17 PM

Quote:

Originally Posted by Scuba_Dave

I've known several commercial properties that used the breakers to turn the lights off & on every day
I guess that would exercise them...maybe too much ?
Only about 700 flips a year

depends. There are breakers that are designed, and as such, rated for use as a switch. They will be labelled SWD (not sure what it stands for. I figured Elmer Fudd told them it was a Switch Wated Device) actually I think it is switch duty.

frenchelectrican · 07-09-2010, 11:18 PM

Dave.,

Not really if the breaker have "SWD " stamped on the handle they are designed as switching load and they last little longer than standard breaker they are useally found in 15 or 20 amp single pole breaker { either 120 or 277 volts verison }

IIRC I think they can take up to 10,000 cycles but there are few other type of breakers most will not be listed in the redentstail side.

Merci.
Marc

Jim Port · 07-14-2010, 03:35 PM

Check out this discussion of breaker testing.

http://www.terrylove.com/forums/show...ease&highlight=

jbfan · 07-14-2010, 04:33 PM

I always wondered if this guy was that guy!!!!!!!!!!

Jim Port · 07-14-2010, 07:42 PM

Quote:

Originally Posted by jbfan

I always wondered if this guy was that guy!!!!!!!!!!

Great, either an inside joke or something else to try and figure out

.

I was still trying to figure out how placing a 50 amp breaker in series with a 15 amp breaker would tell you the trip level or is the breaker was good. After all it is just a switch, there is no load with the larger breaker. And why would you need an LED, couldn't you see the tripped breaker? Along with how you test a breaker under no load conditions.

Quote:

To test 15A and 20A breakers I put a 50A spare breaker across the line and switch it on. I have an LED wired in to tell me when the voltage disappears, which has always been 'instantly'. If the lower amp breaker doesn't trip the 50A will, and if the LED doesn't go out I switch off the 50A breaker after one second or so.

Yoyizit · 07-14-2010, 08:18 PM

Quote:

Originally Posted by jbfan

I always wondered if this guy was that guy!!!!!!!!!!

Could be. . .
1. I plagiarized his stuff
or
2. We have the same ghost writer
or
3. I was the kid in the avatar
or
4. I was the snake in the avatar

You're good, Mr. Fan.

http://en.wikipedia.org/wiki/Jimmy_Buffett

BTW, that Marne guy wasn't the most obnoxious, condescending turkey that I ever met in my whole long and miserable life, but he was sure up there!

I hope Cookie is doing better. I always felt bad for that lady.

jbfan · 07-14-2010, 08:49 PM

Jim, Check the link you posted and see who started that thread on terry loves site.