Electric circuit breakers ? ...thick or thin size

[DTCOOPER]

you can actually get a 2 pole thqp style breaker (thin) that will supply you 240v.
It will only take the space of 1-1" thick breaker, but it will tap both bus bars.
Just make sure you know which breaker you have.

Again, I have never seen any real world proof of the thin breakers being any more susceptible to failure or nuiscance tripping than the thicker ones..
The inverse time element in them is designed in a way to negate the effects of ambient heat.. Be them in a smaller housing, larger housing, etc..

 

[MT. Sparky]

The thin breakers are usually used because the electrician or home owner that installed the panel did not put in a big enough one to begin with. I have had problems with the actual connections to the bus on the thin breakers. Just make sure you use a big enough panel to begin with and stay away from the thin breakers if possible.

 

[RadarTech]

I just finished building a house a few months back and learned a few things on the way...
First.

These are called Tandem breakers..
and not all boxes support them.

they can be both good and bad..
Right now I wish my electrician had used a Tandem capable box.... BUT ARRG...
he did not so I have (2) 200 amp boxes...

second and last---
like others have said- they can have connection problems.. BUT that varies from vendor to vendor-- Square D worked better than cutler..


Later,
J

 

[DTCOOPER]

You are confusing TANDEMS WITH THINS..
Ge makes Thins: THQP 115, 120, 130, then some 2 pole THINS THQP220, 230, 240, 250, etc.
Tandems are those such as ITE Siemens and Square D make.. Q1515, Q2020, etc. QO1515, QO2020, etc Those are TANDEM single pole breakers.. Not 2 poles. They are actually 2 single pole breakers.

Just as I said above, all panels will not accept them. Typically you get a panel such as a Siemens G3040MB1200. The first number represents the number of full 1" spaces. (30) the second number represents the total number of circuits the panel is capable of accepting (40). That means that panel will accept 20 thicks, and 10 tandems (20 circuits) for a total of 40 circuits. A G4040MB1200 will not accept any thins. It will only accept 40- 1" thick breakers. Be they single pole, 2 poles, or a combination thereof.

In a home at or near the 2000 sq ft mark, we will typically sell either 2- 4040 panels or 1- 4040 panel and 1- 3040 panel. They'll use the larger of the 2 for real loads such as AC, oven, dryer, and some convenience outlets. Then the other panel for all other lighting and receptacle loads such as bathrooms, bedrooms, etc..

As with anything man made, anything is subject to failure at any time.. However, in 20 years of selling all brands, GE, Siemens, Cutler Hammer, Square D (now), I have not seen a handful total of these thin breakers that "went bad"...

 

[woodlandfarms]

Daniel, thanks for the information. I learn something new and usefull here every day!

So, on our manufactured home in WA, by code it has a pole outside with a meter box and breakers. Inside the house is another breaker box. The local electrician said that this was a code requirement and manufactured have a tendancy to flame up and go up quickly. The box and master breaker outside is designed to keep firefighters safe so they can quickly find a master breaker location. Not sure why a regular house would not require this but whatever.

What I was getting at is that this box would only accept a particular kind of breaker. I was trying to add a 50AMP breaker for an outdoor welding outlet (220). I went to the local store, they said tough luck, the box is only designed for 110's and breakers do not exist the way I want them. Some old crusty guy followed me out and once out the door he said he can't say this inside, but just buy the breaker that does not fit, take a dremel, and cut a few slots wider so it will fit. I remember having to cut the front slot on the breaker longer, and then I had to create a gap betweend the two 50AMP breakers, just used the dremel and a cutoff wheel and compared it to the one 220 breaker that was in there.

 

[DTCOOPER]

yes sir, it happens all the time !!
If you read many of my posts here on the forum, you'll find that I believe most things are over engiineered.. And electrical materials, and codes are in that category as well..

Most manuf home mfrs use Cutler Hammer Breakers, that are specifically made for them..
I am sure it's a way to get "oem" type pricing while still using a "brand name"..

Most mfd home installs consist of an outside disconnect as you have, with a "feed thru" type panel. Usually an 8 circuit with a 200 amp main breaker, and feed thru lugs on the bottom. This allows you some circuits outside the home fed from that panel, and 200 amp protection for everything from that outside panel..

I actually installed a 40 circuit 200 amp main with feed thru lugs outside on our mfd home a few years ago... That afforded me the ability to power the barn, chicken house, roping arena lights, and landscape lights from that outside panel.. while still feeding and protecting the house panel inside..

Our new home we're in now, I have a 225a 40 circuit main panel with feed thru lugs out at the pole, then fed underground to the house panel that feeds all large loads, then on to an interior panel that powers lights, receptacles, etc..

I am adding a 125a 2 pole breaker out at the service panel to feed the barn 250 feet away...

A lot of work initially when the house was built, but I have power anywhere I want to have it now.

 

[EddieWalker]

When buying new, I like the GE contractor panels with breakers included. You get a good value for your money with these sets. The breakers that they come with are one inch models, which makes me think they must be cheaper to make. When buying breakers, I prefer the smaller ones since the knockouts for the panel always have a gap in them with the one inch breakers. I can put a half inch breaker in that space and fill up the hole. It's just a matter of making it look nicer for me.

Two things that I don't understand is how many amps worth of breakers can you put on a 200 amp line? I was in a house recently that was less then a year old. The electricians never finished the job and the homeowner gave up on getting them out there. It was just a switch for her fountain that they didn't do, so I was in and out of there. In her breaker box, I added up the total rating of her circuits to 850 amps. I realize that you can go well over 200 amps, but don't know how far you can do this. Is there a limit? This house was in a brand new, high dollar development with building code and inspectors. The builder is well known, but I don't know the electricians other then a name she gave me. They passed the final inspection, so I'm assuming the breaker box was legal. I also understand that at no time will all the breakers be used to capacity, so there is always room for more breakers then the panel is rated. 850 amps just seemed like allot more then I would have thought was allowed.

The other thing that I don't understand is having two single pole breakers connected together. In this case, it's at the church that I do repairs at. I had to replace a 4 way light switch in their gym. The breaker for that switch was 20 amps and it was connected to another 20 amp breaker. To turn one off, I had to turn both off since the bar connected to both breakers. It's two one inch breakers, 120 volts, 20 amps and two different lines. What is the reason for these type of breakers?

Thanks,
Eddie

 

[studor]

Eddie -- I think the joined breakers were originally for spots like kitchens where a plug can be split and both sides fed from the joined breaker so when you turn off the breaker to work on it both sides go off. Most of those breakers have the bar or joiner as removable, it just seems that they do not get removed in applications that do not need the bar. Some have a liitle aluminum pin and others have a spring steel clip to hold them together. It sounds like in your application you should separate them
Regards

 

[DTCOOPER]

per code, breakers can be tied for a matter of convenience, if they truly each operate a single 120v circuit.

But where people run into problems is tying 2- single pole breakers together,m to feed a 240v circuit.. One side will trip, and still leave 120v feeding the other leg..

 

[LarryD]

Eddie, lots of considerations go into determining the service size and panel sizing for a structure. Some things are taken at 100% load while others are derated and other values are simply a value based on square footage.

Here is a link to a web site that has a residential load caluculator you can download. forth item from the bottom.