Replacing 2-pole breaker with 1-pole breaker


  #1  
Old 04-24-22, 03:59 PM
B
Member
Thread Starter
Join Date: Apr 2022
Posts: 3
Received 0 Likes on 0 Posts
Replacing 2-pole breaker with 1-pole breaker

My 100 amp panel in my home is full and I want to add a new circuit. Can I replace the existing, 2-pole 30 amp circuit breaker which occupies a double slot (2 inches wide) with a 1-pole, tandem 30 amp CB that only occupies a single slot (1 inch wide)? Obviously, that would then free up a CB slot to add a new circuit.
 
  #2  
Old 04-24-22, 06:54 PM
Tolyn Ironhand's Avatar
Group Moderator
Join Date: Nov 2007
Location: United States
Posts: 15,029
Received 627 Likes on 536 Posts
First, you need to make sure your panel will accept tandem breakers. You can often find this on the label on the inside of the panel cover.

A two-pole breaker has to span two slots as that is the only way to get 240 volts. You can get tandem two-pole breakers that have a two-pole 30 in the middle and other breakers on the outside breakers. These are often called Quatplex breakers.

Another option is to remove two breakers, install a larger breaker, and install a sub-panel next to the main panel. You then extend the two circuits you removed in the main panel to the sub-panel.
 
The following users liked this post:
  #3  
Old 04-24-22, 07:25 PM
J
Member
Join Date: Sep 2002
Location: welland ontario
Posts: 8,341
Received 462 Likes on 382 Posts
A two pole 30 amp will be a 240 volt supply. If your panel accepts tandems the best option is probably a quad that 30 amp handle tied to supply the 240 volts to the existing device.
This may not be the actual one you need but it will look similar.

 
The following users liked this post:
  #4  
Old 04-25-22, 04:01 AM
A
Member
Join Date: Mar 2014
Posts: 842
Received 109 Likes on 91 Posts
What is connected to the present 2 pole 30amp breaker now?
I only ask because some homeowners just look at the panel with the cover on and assume the breaker in there is presently being used when in fact no wires are going to it.
 
  #5  
Old 04-25-22, 05:28 AM
L
Member
Join Date: Nov 2015
Posts: 1,804
Received 176 Likes on 151 Posts
If you are getting this inspected or wants to meet the code, tandem breaker may not work. 2017 and up NEC requires pretty much all 120V circuits in home to be AFCI protected. AFCI breakers do not come in tandem.

You can install AFCI receptacle at the first outlet instead and must be shorter than 50ft for 14AWG and 70ft for 12AWG to first outlet.
 
The following users liked this post:
  #6  
Old 04-25-22, 08:06 AM
B
Member
Thread Starter
Join Date: Apr 2022
Posts: 3
Received 0 Likes on 0 Posts
In response to AFJES, the existing 2-pole, 30 amp CB is wired to the dryer outlet in the garage. However, I use a gas dryer and so the dryer outlet is not used actively.
 
  #7  
Old 04-25-22, 11:41 AM
A
Member
Join Date: Mar 2014
Posts: 842
Received 109 Likes on 91 Posts
BillRamsey:

My 100 amp panel in my home is full and I want to add a new circuit. Can I replace the existing, 2-pole 30 amp circuit breaker which occupies a double slot (2 inches wide) with a 1-pole, tandem 30 amp CB that only occupies a single slot (1 inch wide)? Obviously, that would then free up a CB slot to add a new circuit.
color=#222222]In response to AFJES, the existing 2-pole, 30 amp CB is wired to the dryer outlet in the garage. However, I use a gas dryer and so the dryer outlet is not used actively.]
If you are no longer using this electric dryer then you can remove the 2 pole breaker and now you will have two positions available for breakers. Since you are no longer using the dryer there is need to put in another breaker in its replacement - also putting in a tandem 30amp breaker would not give you the 120/240V required for the dryer anyway. The wires you remove from the present two pole dryer breaker place a wire nut on each of the two wires and tuck them in the panel or you can remove the cable all together from the panel and place it in a junction box near the panel and label the cover for this junction box for future reference.

Since you have two breaker positions available now you may install either one two pole breaker or two single pole breakers for your new needs. You may only install tandem breakers in this panel if this panel is rated for tandems and only if the panel is rated for tandems. You may not install a tandem breaker in this panel only because it fits if it is not rated for tandems as this may very well cause serious dangerous issues in the future.

If you would like to have more space available for the future then you can now use this two spaces available to install a breaker to feed a sub panel which will then give you even more breaker spaces available. Installing a sub panel in this case is really not that difficult. However, understand that since you have a 100amp main panel installing a sub panel will only give you more breaker spaces not more capacity over your 100amps of your main service.
 
The following users liked this post:
  #8  
Old 04-26-22, 08:19 AM
B
Member
Thread Starter
Join Date: Apr 2022
Posts: 3
Received 0 Likes on 0 Posts
Thanks for your response. I’d like to maintain the existing connection to the dryer if at all possible. My ultimate objective here is to install a 50 amp EV charging outlet which would only be used overnight when no other load was on the panel. I think I’ll have my panel assessed to determine if it is designed to accommodate tandem CBs. The house was built in 1993 and so, is 29 years old.

If the panel can accommodate tandem CBs, I’ll proceed with installing the 30A/50A tandem breaker and installing a NEMA 14-50 box/outlet. If not, I’ll merely purchase a 10-30 NEMA adapter and charge my EV from the dryer outlet. Naturally, the NEMA 14-50 would be preferable to the NEMA 10-30 because it will charge an EV more quickly.
 
  #9  
Old 04-26-22, 01:23 PM
A
Member
Join Date: Mar 2014
Posts: 842
Received 109 Likes on 91 Posts
You can't install a 30/50 tandem. Doing so will only give you one 240 circuit and two 120 circuits not two 240 circuits. Install a small sub panel and use this two pole breaker position to feed the new sub panel. That would be your best bet if you want to keep the circuit for the dryer active.

I said this like this that you can't have two 240v circuits because although your one 240v circuit will give you 240volts the two positions will not be able to be tied to each other. Code dictates that when one breaker of a tied trips then both must trip. This can't happen with a 240v tandem. Your two outside breakers can't be tiedf to each other.
 
The following users liked this post:
  #10  
Old 04-26-22, 05:30 PM
L
Member
Join Date: Nov 2015
Posts: 1,804
Received 176 Likes on 151 Posts
https://www.amazon.com/Siemens-Q2305.../dp/B000VYKYR4

This is what you need if you want 2 pole 30A and 2 pole 50A. It is 2 pole Quadplex breaker, common trip.

You will have to check if your panel can accept tandem breaker in slot you want to put this breaker.
Some panels don't allow tandem and some allows only if few specific slots. There will be a diagram in the panel indicating this and you can also check bus bar itself.
Bus bar will have a groove cut in the middle (between left and right side breakers.) of tandem breaker is allow.
 
The following users liked this post:
  #11  
Old 04-26-22, 06:59 PM
Tolyn Ironhand's Avatar
Group Moderator
Join Date: Nov 2007
Location: United States
Posts: 15,029
Received 627 Likes on 536 Posts
You can install AFCI receptacle at the first outlet instead and must be shorter than 50ft for 14AWG and 70ft for 12AWG to first outlet.
You can also put an AFCI device next to the panel.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: