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
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??!
I've never seen anything but standard circuit breakers from a half dozen
manufacturers at HD. Sylvania is close to Murray so I'd try that. The others
that may fit are GE and Homeline, but its gonna depend on the buss in your
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.
I challenge the thought that someone makes a "non-current limiting"
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.
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...
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.
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
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
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