Electric circuit breakers ? ...thick or thin size

[G McCall]

What is the reason for a thick ("1") or thin (1/2") size elec. panel circuit breaker ? GE brand I think.

Are there load differences ?

I want to run a electric line from my panel box to a 70amp rated outlet box with 1 -30Amp RV outlet and 2 - 20Amp receptacles. Should I use a thick or thin breaker ?

 

[billbill1]

The amp rating on the breakers will determine the amperage that will trip the breaker. The thickness of the breaker is determined by the knockout size of the breaker panel. (those little squares where the breaker will go.) Also determined by how the breaker attaches to the buss bar inside of the panel. Your panel has numbers that will tell you which size (breakers) you need. Hope I explained it so it helps you.

 

[JimW1950]

I assume that both the 30 AMP & the 20 AMP circuits are to be 110, rather than 220. However, if you were installing 220 then remember that two of the thin breakers in a slot for a traditional (thick) breaker will attach to the same buss bar and not deliver 220. 220 requires each pole to be attached to a different buss bar. Sometimes folks try to use two thin single pole breakers in one thick breaker slot and are confounded when they do not obtain 220. Best bet is to always use double pole breakers for 220 to avoid this problem. Hope I did not confuse you.

 

[G McCall]

billbill1.......

the few breaker boxes I have seen will accept both the thin and think size breaker. I have removed a thin and replaced it with a thick thinking the thick was more "heavy duty" or would carry a full amp load longer. Probably a misunderstanding on my part. I can knock out an extra block for the thick to go into place.

But I am asking if the thick breaker is any more durable than the thin breaker ?

 

[mad_planter]

I believe the only difference is that the thin ones are designed to allow you to "split" a breaker from one to two circuits if your box is full and you need more space.

 

[G McCall]

I assume that both the 30 AMP & the 20 AMP circuits are to be 110, rather than 220. However, if you were installing 220 then remember that two of the thin breakers in a slot for a traditional (thick) breaker will attach to the same buss bar and not deliver 220. 220 requires each pole to be attached to a different buss bar. Sometimes folks try to use two thin single pole breakers in one thick breaker slot and are confounded when they do not obtain 220. Best bet is to always use double pole breakers for 220 to avoid this problem. Hope I did not confuse you.

Jim
I understand what you are saying and yes........all outlets are for 110.

The fact is though, that a single pole thin or thick 30amp will fit in one spot, so I am wondering if thick is better.

 

[billbill1]

In that case, no- the thicker ones are not more durable.

 

[DTCOOPER]

The onnly reason GE made the THQP style breakers was to allow them to make a smaller loadcenter, and still get a certain number of circuits in the panel..
All spaces on a buss will not accept the thins.. You can't take a 42 circuit panel and miraculously get 84 circuits out of it by using all thins..
As far as durability, I have sold thousands of thins along with thicks in my 20 years in the business, and have not seen any higher rate of failure from thins than thicks..
Hope that helps you out..

And FYI - someone mentioned using a 2 pole breaker for a 220v load.. That is the ONLY safe way to get a 240v circuit.. Tying 2 single poles together will not get you an integral trip circuit breaker.. Meaning if one pole overloads, then it won't necessarily trip the other side along with it.. And that could lead to a dangerous situation..

 

[woodlandfarms]

I have heard a number of electricians suggest that the thinner breakers are more susceptable to generate heat, thus creating a fire or tripping hazard.

I personally don't buy this theory as these things are UL rated (And I trust UL for the most part). When adding circuits to the house I just pull the "thick" breaker and add a 2 switch thin.

Someone should address, though, the capabilities of the breaker box. I have never understood a 100 AMP, 200 AMP breaker box and the looks I get at the store when I say I don't know...

Oh, and Gmcall. I did this same thing. For my box it had to be a thick breaker to accept both 110 poles to create the desired 220.

 

[studor]

In this time of reducing manufacturing costs to a minimum, the difference between a 100 amp panel and 200 amp panel is usually price and the main breaker. I also believe the difference in performance between thick and thin breakers is perception (and sometimes price, the thinner ones being more expensive occasionally)-- If the breakers were overheating and failing regularly I would be looking for another complete panel -- JMHO
regards

 

[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.