Default Can I test to verify amp rating on a circuit breaker with a multimeter
#1
Member
Thread Starter
Join Date: Jan 2006
Location: Louisiana
Posts: 45
Upvotes: 0
Received 0 Upvotes
on
0 Posts
Default Can I test to verify amp rating on a circuit breaker with a multimeter
My circuit breakers have red stickers on the switches showing the amp rating (20 amp and 15 amp). I would like to verify that this is correct. Can I use a multimeter to test this? If so, do I test this at the panel at the wires coming out of the breaker or at a receptacle that is connected to that circuit?
#2
Why in the world would you want to "Verify" a rating placed there by the manufacturer? They are individually tested prior to being placed on the market. If you have a question of a breaker, replace it. But to answer your question, no you can't test a breaker with a multimeter.
#3
Member
Hi toolmonkey, sometimes people want to know how much load is on a breaker, and even for that a multimeter would be challenged to give you a reading of any value. Just look at the test leads, they were never intended for 20 amps.
Then, understanding breakers, they have a fairly large tolerance to variations in load. A 20 amp breaker might handle 30 amps for a very short duration, but might take minutes to trip at 21 amps. These are not the correct numbers, but there are wide variations. But, as Chandler said, they are all tested at the factory and designed to high standards because their function demands it. As stated, if you have some you question, replace them and you can have a high confidence the new ones will function as intended.
Now, if you are having a problem that is prompting this question, post it and the electricians here (not me) are very good and can help.
I have to comment that you chose your handle well
Bud
Then, understanding breakers, they have a fairly large tolerance to variations in load. A 20 amp breaker might handle 30 amps for a very short duration, but might take minutes to trip at 21 amps. These are not the correct numbers, but there are wide variations. But, as Chandler said, they are all tested at the factory and designed to high standards because their function demands it. As stated, if you have some you question, replace them and you can have a high confidence the new ones will function as intended.
Now, if you are having a problem that is prompting this question, post it and the electricians here (not me) are very good and can help.
I have to comment that you chose your handle well
Bud
#4
Member
Join Date: Feb 2009
Location: Iowa
Posts: 310
Upvotes: 0
Received 0 Upvotes
on
0 Posts
Toolmonkey, are you sure the rating isn't on the face of the switch that's for the breaker. If it isn't then it's a very old breaker and then I would just replace them to be safe. Sent us a picture of it and maybe we can help locate it on the breaker.
Jim
Jim
#5
Member
What you can do is load up the circuit to see when it trips. Keep your fire extinguisher handy!
Or, you can contact the mfr to see if they can give you the UL or other test data on the breaker.
If you suspect your breaker is bad, it would be cheaper and easier to replace it with an identical one.
To make a decent ammeter, you can get an "amp clamp" that places a current transformer (CT) around the hot wire. The amp clamp lead plugs into your multimeter. You then multiply the value on the meter readout by a factor specified in the amp clamp's instructions and voila, that's your amperage.
Or, you can contact the mfr to see if they can give you the UL or other test data on the breaker.
If you suspect your breaker is bad, it would be cheaper and easier to replace it with an identical one.
To make a decent ammeter, you can get an "amp clamp" that places a current transformer (CT) around the hot wire. The amp clamp lead plugs into your multimeter. You then multiply the value on the meter readout by a factor specified in the amp clamp's instructions and voila, that's your amperage.
#6
Member
Thread Starter
Join Date: Jan 2006
Location: Louisiana
Posts: 45
Upvotes: 0
Received 0 Upvotes
on
0 Posts
I know I *should* replace my panel, but I currently do not have the money to do this. Its an old FP, which I was told is *crap*.
See image below, the ratings are red stickers. It may also have a rating on the side, but its hard to see since its recessed in the sheetrock.
http://img.photobucket.com/albums/v1...e/IMG_5756.jpg
See image below, the ratings are red stickers. It may also have a rating on the side, but its hard to see since its recessed in the sheetrock.
http://img.photobucket.com/albums/v1...e/IMG_5756.jpg
#7
Member
Join Date: Feb 2009
Location: Iowa
Posts: 310
Upvotes: 0
Received 0 Upvotes
on
0 Posts
I know I *should* replace my panel, but I currently do not have the money to do this. Its an old FP, which I was told is *crap*.
See image below, the ratings are red stickers. It may also have a rating on the side, but its hard to see since its recessed in the sheetrock.
http://img.photobucket.com/albums/v1...e/IMG_5756.jpg
See image below, the ratings are red stickers. It may also have a rating on the side, but its hard to see since its recessed in the sheetrock.
http://img.photobucket.com/albums/v1...e/IMG_5756.jpg
Jim
#8
Member
Thread Starter
Join Date: Jan 2006
Location: Louisiana
Posts: 45
Upvotes: 0
Received 0 Upvotes
on
0 Posts
toolmoney, They look like they are FP's. If they are the stab-lok type they are a fire hazard. I believe the new breakers they make have a white label on them and they are safe. If it was me I would replace the panel and breakers. Maybe see what evryone else has to say.
Jim
Jim
#9
Member
Join Date: Feb 2009
Location: Iowa
Posts: 310
Upvotes: 0
Received 0 Upvotes
on
0 Posts
Federal Pacific Electric Panels: Fires Waiting to Happen, Debate Waiting to Be Ended
Jim
#10
Member
Thread Starter
Join Date: Jan 2006
Location: Louisiana
Posts: 45
Upvotes: 0
Received 0 Upvotes
on
0 Posts
As for now just don't put a big load on the breakers. Here's a site that will give you some information about your panel.
Federal Pacific Electric Panels: Fires Waiting to Happen, Debate Waiting to Be Ended
Jim
Federal Pacific Electric Panels: Fires Waiting to Happen, Debate Waiting to Be Ended
Jim
#11
Member
Join Date: Apr 2004
Location: Ontario Canada
Posts: 1,694
Upvotes: 0
Received 0 Upvotes
on
0 Posts
FP USA did.
The Canadian division kept on, and is currently owned by Schneider Electric, whom active sell newer Stab-lock panels and breakers to the Canadian market.
The Canadian division kept on, and is currently owned by Schneider Electric, whom active sell newer Stab-lock panels and breakers to the Canadian market.