What breaker do I need? Q2020 or Q2020NC?

[toller]

I am putting in a new circuit in my workshop (bought a 12a shopvac and it makes the lights flicker) so I need to replace a full size 20a breaker in my Sylvania box with two half size breakers.

I went to HD and they had two of them, a non-current limiting breaker for $15 and another one for $10. I asked the clerk what the difference was; he said there wasn't any difference and told me to buy the cheaper one. That didn't make any sense so I asked a guy in the aisle if he knew. He didn't but after looking at them pointed out that cheap one has a little contact and the expensive one had a big contact. He said the expensive one can be used in all boxes, but the cheap one can be used in all boxes. That makes a lot more sense, but still doesn't explain what non-current limiting means.

So, does anyone know what the difference is, and which I should use. Funny think is I have put in two others without encountering this issue before. I wonder if I used the right ones??!

[RBM]

[toller]

Subject: Re: What breaker do I need? Q2020 or Q2020NC?

I am sorry, maybe I wasn't clear enough. Both these breakers are Siemens (who makes identical breakers under the Murray name) They are in boxes next to each other on the shelf and outwardly look identical. One is current limiting, and the other is non-current limiting. I don't know is the right one, or what current limiting means.

---------- Although I would still like to know the difference for future reference, it became a bit academic after writing the last post. Rummaging through my electrical bin in search of a light switch, I found a Sylvania 20-20 I took out last year when I put a quad breaker in. So, I am all set for now, but will face the same question if I ever have to put another circuit in.

[SQLit]

I challenge the thought that someone makes a "non-current limiting" residential breaker. If the breaker does not limit current then would it not be called an switch?

Inside your panel should be a piece of paper that tells you what breakers are listed for your service.

[RBM]

[John Hines]

A quick google turns up that the Q2020NC is non-interchangeable, "for retrofit use on I-T-E load centers built prior to 1965".

[Tekkie]

posted for all of us....

Oh brother, another one! SQL it gets pretty wacky sometimes doesn't it?

[bumtracks]

q2020 is the standard one

[JollyChollie]

NC = Non-Current Limiting Circuit Breaker ~ Non-CTL, (Not Circuit Limiting ~ No Rejection Clip; Not Limited to Only Certain Circuits). The ones with the NC will not fit in some Siemens Boxes, (some say that these are designed for Circuit Boxes built before 1965, or 1968; however mine was installed in 1993 and only the Z2020NC will fit mine).

If you want more Detail beside the ones without the NC will not fit, (which is good enough for me), such as Specs, then I suggest you go to...

[Sam E]

[snip]

Non CURRENT limiting?

I know someone who lost a house because of one of those (FPE). She said it was glowing red before the fire started.

[snip]

[Paintedcow]

What's the point of having a breaker if it's "Non CURRENT limiting"? I never heard of any such type of breaker either....

By the way, if you see any electrical stuff glowing red. SHUT OFF THE FRIKKIN POWER! Then call the fire dept. (If you cant go indoors to shut off the power, PULL THE METER, but in that case, call the F.D. first.

[gfretwell]

CTL means Circuit Total Limiting (not current) A CTL has a hook or some other protrusion that prevents it from going in a non-CTL slot The breaker he is talking about is a "piggy back" (2 breakers in one slot) Panels are rated by the total number of breakers they will hold and some will say 20/30 or 20/40 referring to how many slots will accept a piggy back breaker. (half will have the cut out for the piggy back in a 20/30, all in a 20/40) Some will not accept any piggy back breakers.

OTOH if you buy a non-CTL breaker it will fit anywhere but not legally.

[Robert Thomas]

FPE (Federal Pacific Electric) lost there UL rating because of that.