Circuit Breaker Question

Junkyard Dog

Super Anarchist
2,877
13
N/A
Sorry for my ignorance, but I need to find out if a 40 Amp 240v circuit breaker running an electric oven/range can be replaced with two 20 AMP single pole circuit breakers ganged together.

I'm trying to help out an elderly neighbor, but her stuff is very old and she can't afford to replace the entire panel.

The panel is antique, and finding replacement breakers is difficult.

While the brand is different, can I replace something like this:

p_1000100561.jpg


with something like this?

iu


 

tommays

Super Anarchist
1,366
43
Northport
1. While it might not need the full 40 amps (name plate on appliance should say) 20 is unlikely to be enough and needs to offer identical protection such as shutting off BOTH poles in a fault condition which is a requirement for this type of breaker 

2. It’s critically important that the breaker “snaps” onto the lugs correctly to avoid a fire from the excessive heat a bad connection would make 

3. The second breaker you picture has the poles connected which should function for tripping both 

 
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mikewof

mikewof
44,147
1,021
Is the original Square D? If so, Schneider likely still makes that 40 amp one. It has to snap in correctly, usually can't cross brands. I needed some really weird breakers in the Square D slim tandem format, but I couldn't find them at the home stores. I went to the Square D dealer. Call this guy, I bet he has the one you need in stock, and the company is employee owned ...

Mike Smith
Dealers Electrical Supply
Denver
303-592-2800
[email protected]

If he asks who sent you, I'm a friend of the late Kurt, the mechanic on Downing.

 
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dyslexic dog

Super Anarchist
3,814
293
Michigan
First, my thought is if you don't understand it, you shouldn't be doing it. 

The Sq D breaker is a two pole 40a per leg breaker with one handle. No, you can not put two twenty amps together safely. Two 40a single pole are odd ducks but they are available but why would you do that? 

What is it you can not find? a QO240 breaker pictured?

 

Ventucky Red

Super Anarchist
11,057
1,064
I don't think what you're looking for can be found at Home Depot... go to a REAL electrical supply house.  I do believe the Square D still makes them.

https://www.grainger.com/product/1D311?ef_id=EAIaIQobChMImtC73Ljx9gIVvyitBh1wyQxJEAQYBSABEgJEkPD_BwE:G:s&s_kwcid=AL!2966!3!281698275261!!!g!470952775331!&gucid=N:N:pS:paid:GGL:CSM-2295:4P7A1P:20501231&gclid=EAIaIQobChMImtC73Ljx9gIVvyitBh1wyQxJEAQYBSABEgJEkPD_BwE&gclsrc=aw.ds

Personally, I wouldn't mess with it.  I would help your neighbor get an electrician in there and have them look it over.  If it is tripping, maybe there is some other problem that needs to be looked at. 

Lastly, maybe your neighbor needs to upgrade the stove to one that draws less power.

 
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Point Break

Super Anarchist
25,860
3,453
Long Beach, California
Well..............I would still run the question by an electrician but from a layperson point of view..........a single 40 amp breaker is meant to trip at 40 amps.......duh........a ganged 20 amp in a 240 configuration would protect each side or phase of the circuit at only 20 amps. If the oven draws 40 it would trip the 20 amp breaker on either/both sides?

What am I missing here?

 

mikewof

mikewof
44,147
1,021
like someone asking about handling a loaded gun

if ya gutta ask ..... Don't touch it !!!!!!
I had to change some breakers, was very much afraid of the box. My electrician friend told me that it's no big deal, just turn off the main breaker and get to work. Luckily, he was standing right there. I turn off the main, go to pull out the breaker, he's like "woah, man, what are you doing?" "I turned off the main." "But the bottom of the circuit is still hot, you nearly touched it!"

I was more careful after that, so yeah, you're probably right.

 

Mrleft8

Super Anarchist
25,133
3,225
Suwanee River
40 amps!!!!??? My 30" Bandsaw didn't draw anywhere near that, even on start up!

Any single household item drawing over 40A is broken in some manner.

 

F_L

Anarchist
820
148
Canyon Lake, TX
40 amps!!!!??? My 30" Bandsaw didn't draw anywhere near that, even on start up!

Any single household item drawing over 40A is broken in some manner.
The industry standard for an electric stove is a 50 amp double-pole circuit breaker.

The above from google.

 

gptyk

Anarchist
605
341
California
The industry standard for an electric stove is a 50 amp double-pole circuit breaker.

The above from google.
Also by my knowledge and experience. An electric range can really suck it down. 

Upthread is correct. A dual pole 40A with a tie is what is needed. if you can verify 6g wire 50A would be ok. 8g would be 40A.

What brand breakers? Some (like zinsco) it's way better to replace the panel. Yes, it's expensive. But so is a total fire loss.

 

Cal20sailor

Super Anarchist
12,167
3,002
Detroit
The industry standard for an electric stove is a 50 amp double-pole circuit breaker.

The above from google.
It's been eons since I thought about any of this but the above is exactly what my condo has with a very plain vanilla electric stove.  I see 240v, and I run for cover.  I enjoy peace of mind way too much.

 

Chris in Santa Cruz CA

Super Anarchist
5,524
999
earths surface
One of my long time friends is a master electrician and lives .8 miles away. Has helped me many times. I can run Romex and wire up 4 gang switch boxes and gfci sockets etc. if has to do with a box, circuit design/gauge, or breaker, he gets called and he gets paid. The code exists for a reason and that reason is fire. Fire is bad. He not only knows the code he knows what you should do beyond the code so you never have to think about it again. Running 220 out to an out building to do x? Design the circuit for 2x or 3x just in case a potter wants to put in a kiln or someone wants to weld. Running it underground? Oversized conduit and leave a fish line in it in case someone wants to pull tv cable or cat 6 or just run it all at once one time. Pulling cable is fun.

 
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