Tadem breakers...Any code guru's?

[lynchmob723]

Tandem breakers...Any code guru's?

I have a Cutler Hammer ch30b100d panelboard that I have filled up.

Code allows a max of 42 ckts per panel. However I believe the panelboard has to be rated for this as well.

My panel is ch30b100d as mentioned above. Im guessing I cant use tandem breakers to exceed my 30 spaces with more than 30 circuits right? or can I?

 

[mrb]

that panel is a 30/30 meaning 30 spaces and 30 max breakers. You cannot put a tandem in it. For example a 30/40 has 30 spaces, ten of which can accept a tandem for a total of 40 breakers.

You will need to install a subpanel or replace it.

 

[DJDD]

Your easiest option is to put in a sub-panel and add the tandem breakers you need, assuming you don't go over the 100A limit of the original panel. Your best and safest option would be to go with a larger panel and upgrade the circuit to 150A. This will allow future expansion without putting too much draw on the circuit. What are you trying to add on that requires a tandem?

 

[mrb]

install another panel alongside it, fed from a 100a breaker in the original panel. Move a couple circuits over to the new panel to make room for the 100a breaker, and install your new circuits in the subpanel. obviously if your new loads plus what is in the original 100a panel are over 100a you have a problem, but it sounds like you just need more circuits.....

 

[DJDD]

install another panel alongside it, fed from a 100a breaker in the original panel. Move a couple circuits over to the new panel to make room for the 100a breaker, and install your new circuits in the subpanel. obviously if your new loads plus what is in the original 100a panel are over 100a you have a problem, but it sounds like you just need more circuits.....

A bit confused now....

I thought the original panel was only a 100A panel, if so, I thought you couldn't run another breaker the same size as the main? Its been a couple of years since I was in the industry so I might not be remembering correctly. We are of course assuming he has all 30 spaces filled on his main panel and needs to add a tandem.

Being a 100A panel, I'm going to assume that this is a sub panel running from a main 200A service panel somewhere else. Definitely need some more info to really figure out what's going on here.

 

[lynchmob723]

Ya i figured I would have change panels or add a sub panel.
I have 100a service, with 100 main breaker. I just need the tandem to combine two 20a ckts into one space. Just making room for my 50/2 breaker for the garage feed.

 

[mrb]

A bit confused now....

I thought the original panel was only a 100A panel, if so, I thought you couldn't run another breaker the same size as the main? Its been a couple of years since I was in the industry so I might not be remembering correctly. We are of course assuming he has all 30 spaces filled on his main panel and needs to add a tandem.

Being a 100A panel, I'm going to assume that this is a sub panel running from a main 200A service panel somewhere else. Definitely need some more info to really figure out what's going on here.

theres nothing wrong with putting a 100a breaker in a 100a panel. No different than if the first 100a panel had feedthrough lugs and you supplied a second panel from those to get more space. Just make sure your load isnt more than your 100 amps, and that your conductors are properly protected.

 

[DJDD]

theres nothing wrong with putting a 100a breaker in a 100a panel. No different than if the first 100a panel had feedthrough lugs and you supplied a second panel from those to get more space. Just make sure your load isnt more than your 100 amps, and that your conductors are properly protected.

Ok, I see what you mean now. A little rusty on Do's and Do Not's when it comes down to the nitty gritty things, lol.

 

[Aceman]

theres nothing wrong with putting a 100a breaker in a 100a panel. No different than if the first 100a panel had feedthrough lugs and you supplied a second panel from those to get more space. Just make sure your load isnt more than your 100 amps, and that your conductors are properly protected.

If you're trying to run a feeder with the same ampacity as the main breaker in the panel, 100 amps in this example, it'd be worth it to price it both ways. Whether it's a 100 amp 2 pole breaker or a 2 pole subfeed lug kit. A subfeed lug kit looks similar to a breaker but has no overcurrent protection and snaps right into 2 breaker spaces.

His part # would be a CHSF2125 and it's rated for 125 amps. I believe most panel manufacturers make them, I know Siemens does also.

 

[antolod]

If your breakers have place for 2 wires in them (many do) then you don't necessarily need to add tandem breakers, just double up a couple of low load/seldom used circuits.

 

[ranger_dood]

If your breakers have place for 2 wires in them (many do) then you don't necessarily need to add tandem breakers, just double up a couple of low load/seldom used circuits.

Not allowed by code.

 

[Charles (in GA)]

Originally Posted by antolod View Post
If your breakers have place for 2 wires in them (many do) then you don't necessarily need to add tandem breakers, just double up a couple of low load/seldom used circuits.

Not allowed by code.

Code doesn't allow double tapping. However, some breakers, Homeline by Square D, for instance, is designed for two wires to be connected to it, and is listed that way. Of course, that doesn't help the guy with C-H breakers.

Charles

 

[GeorgiaHybrid]

Charles,

Instead of double tapping, can those two wires be pulled outside of the load center, put into a junction box to the side, tied together and a pigtail wire run back to the breaker? If both circuits are seldom used, the junction box is accessible with a cover and the existing wires have enough length to reach the junction box without splicing, it would seem to be feasible. Is something like that allowed by code?

 

[mrb]

Charles,

Instead of double tapping, can those two wires be pulled outside of the load center, put into a junction box to the side, tied together and a pigtail wire run back to the breaker? If both circuits are seldom used, the junction box is accessible with a cover and the existing wires have enough length to reach the junction box without splicing, it would seem to be feasible. Is something like that allowed by code?

you dont have to do that, you can make the splice in the panel. Need to make sure you arent screwing up the phasing of a MWBC when rearranging circuits.

 

[GeorgiaHybrid]

you dont have to do that, you can make the splice in the panel. Need to make sure you arent screwing up the phasing of a MWBC when rearranging circuits.

OK, I didn't think you could make a splice inside the box before tying into the breaker. Ihat's why I don't make a living as an electrician.... I do things the hard way.