Go Back  DoItYourself.com Community Forums > Electrical, AC & DC. Electronic Equipment and Computers > Electrical - AC & DC
Reload this Page >

When to add a new circuit for section of house? When to reuse?

When to add a new circuit for section of house? When to reuse?


  #1  
Old 05-20-24, 07:53 AM
D
Member
Thread Starter
Join Date: Jul 2005
Location: Chicago land
Posts: 733
Received 1 Upvote on 1 Post
When to add a new circuit for section of house? When to reuse?

I believe this is my last question as part of my kitchen remodel which entails removing a wall and replace by island. Otherwise, room/space and basic layout remain the same.
I am trying to decide whether I need to add a new circuit for kitchen lights and island fan.

Old situation
  • The kitchen lights (six can lights) were previously connected to the deck circuit. I suspect this was done by error and more likely were supposed to be connected to "living room" as that wire was routed int he same box.
  • "1st floor lights" circuit: There is a 1st floor lights circuit which controls six ceiling lights and two wall scones (total of eight) in nearby dinning, fire place and hallway space.
  • "living room" circuit: controls 4 outlets, ceiling fan
  • microwave, island outlets all have dedicated breaker.
Changes:
  • Kitchen lights remain the same (two cans are replaced by pendants)
  • There is a new dedicated island range exhaust (previously exhaust was built into microwave)
At first I wanted to add a new dedicated circuit for the six kitchen island lights plus new island exhaust. But adding a new circuit is not trivial. so, I wonder whether this is overkill regardless. One option woudl be to add kitchen lights + exhaust to "living room" breaker.

What woudl you do?

 
  #2  
Old 05-20-24, 08:56 AM
P
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 28,142
Received 2,265 Upvotes on 2,018 Posts
"living room" circuit: controls 4 outlets, ceiling fan
microwave, island outlets all have dedicated breaker.

I am not clear what is on a dedicated circuit and what is shared.

I would want the microwave on it's own, dedicated circuit. Then I'd have the island outlets on their own 20amp GFCI protected circuit.
 
  #3  
Old 05-20-24, 09:12 AM
D
Member
Thread Starter
Join Date: Jul 2005
Location: Chicago land
Posts: 733
Received 1 Upvote on 1 Post
@Pilot Dane:
-> yes, microwave and island outlets(20A) are on dedicated circuit
-> other side of kitchen outlet are on dedicated circuit (20A)
-> dishwasher, disposal dedicated as well
-> fridge will be as well.

My conundrum is about the kitchen lights and the exhaust. Do those need a dedicated circuit or could I connect with "living room"
 
  #4  
Old 05-20-24, 03:55 PM
2
Member
Join Date: Jan 2014
Location: USA near Boston, MA
Posts: 2,331
Received 397 Upvotes on 346 Posts
I think a rule-of-thumb is 8 to 10 outlets on a 15 amp general purpose branch circuit. Each light, receptacle, fan, etc. is an outlet. If you know the amps that each light, exhaust fan, etc, draws you can add them up. Connection to a 15 amp circuit should not exceed 12 amps. My guess is that your kitchen lights and exhaust fan (unless it is very large) can be added to your living room circuit. Do the math to confirm.
 
  #5  
Old 05-20-24, 05:11 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 65,675
Received 4,099 Upvotes on 3,682 Posts
There is no hard and set device count limit.

1st floor lights" circuit: six ceiling lights and two wall scones.
Want to add: six kitchen lights and exhaust fan.

Are these LED light fixtures ?
Current draw of the new exhaust fan ?
The circuit depends on connected load.

If they are recessed fixtures where you can put your own bulbs in.... they count as 60w per fixture.... incandescent or LED's.
 
  #6  
Old 05-20-24, 06:01 PM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 13,993
Received 204 Upvotes on 178 Posts
An old school recessed is figured at the maximum bulb that can be installed, not 60 watts.

Unless the instructions call for a dedicated circuit you should be fine adding the loads to an existing circuit.
 
  #7  
Old 05-21-24, 11:20 AM
D
Member
Thread Starter
Join Date: Jul 2005
Location: Chicago land
Posts: 733
Received 1 Upvote on 1 Post
Here is my current setup:

circuit "living room"
  • ceiling fan - maybe 75W
  • 4 outlets outlet 1: one receiver with 100W - peak 300W outlet 2: floor lamp 60W - maybe a vacuum here and there
So, about 235W max on a continuous load

Circuit "lights 1st floor"
  • 5 ceiling lights (all LED or CFL) 60W total, but lets assume 60W each => 300W
  • 2 wall scones with halogen => 200W
  • 1 small wine cooler ~70W
Total: 570W

New kitchen ceiling load
  • 6 LED's - 12W = 72W (but lets assume 60W each => 360W
  • kitchen exhaust: 385W max
  • total 457W (745 W assuming 60W per light rule)


    Other than load, there is also consideration for logic. Connecting to 1st floor lights seems most logical, living room is the easiest.


 
  #8  
Old 05-21-24, 06:52 PM
D
Member
Thread Starter
Join Date: Jul 2005
Location: Chicago land
Posts: 733
Received 1 Upvote on 1 Post
btw. all my house wiring has a shared neutral for two circuits (split phase). Is this still ok? i.e. in new construction, and in my "extension" use case
 
  #9  
Old 05-22-24, 06:43 AM
2
Member
Join Date: Jan 2014
Location: USA near Boston, MA
Posts: 2,331
Received 397 Upvotes on 346 Posts
Two circuits on different phases sharing a neutral is called a multi-wire branch circuit (MWBC). The two breakers serving those circuits now have to be a two-pole breaker or have a handle tie so both breakers operate simultaneously to prevent the possibility of excessive voltage (240v) on a single circuit.
 
  #10  
Old 05-22-24, 06:50 AM
D
Member
Thread Starter
Join Date: Jul 2005
Location: Chicago land
Posts: 733
Received 1 Upvote on 1 Post
Mine don't have those handles, except for AC breaker.

I have Siemens breakers. Would this work?
https://www.amazon.com/Siemens-ECQTH.../dp/B001PWFRHI

Can they be installed without removing the breakers?


 
  #11  
Old 05-22-24, 07:41 AM
L
Member
Join Date: Sep 2019
Posts: 150
Upvotes: 0
Received 42 Upvotes on 35 Posts
Handle ties for MWBCs were not always required, if your panel is 20+ years old then it met code. The breakers must be removed to install the tie.
 
  #12  
Old 05-22-24, 09:39 AM
2
Member
Join Date: Jan 2014
Location: USA near Boston, MA
Posts: 2,331
Received 397 Upvotes on 346 Posts
Depending on the shape of the hole in the handle, could a pin or bolt be used to tie them together?
 
  #13  
Old 05-22-24, 10:31 AM
D
Member
Thread Starter
Join Date: Jul 2005
Location: Chicago land
Posts: 733
Received 1 Upvote on 1 Post
Would code now require me to add handle to all breakers if I do some electrical work? e.g. adding a breaker for an inductive range?
 
  #14  
Old 05-22-24, 11:49 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 65,675
Received 4,099 Upvotes on 3,682 Posts
The problem with two separate handles on a MWBC is if you shut off one breaker and mess with the wiring you can get shocked.

You are working on your own wiring. As long as you are aware of the dangers working with a MWBC you need to do nothing. At the very least make sure the breakers are one above the other.

Not all breakers will take a tie handle.
Replacing two breakers with a two pole breaker will tie the circuits to one combo handle.
Ranges, ovens, cooktops, electric WH's and dryers require 240v which is a two pole breaker.
 
2john02458 voted this post useful.
  #15  
Old 05-26-24, 08:48 AM
Tolyn Ironhand's Avatar
Group Moderator
Join Date: Nov 2007
Location: United States
Posts: 14,428
Received 899 Upvotes on 760 Posts
I have Siemens breakers. Would this work?
https://www.amazon.com/Siemens-ECQTH.../dp/B001PWFRHI

Can they be installed without removing the breakers?
Yes, those should work and they can be installed without removing the breakers.

Code requires any multiwire circuits to be handle tied either with a multi-pole breaker or with the handle ties like you posted, or some other common disconnect. (handle ties are the least expensive)

Handle ties are available for all types of breakers except for ones that are obsolete.

Typically if you modify a multiwire circuit you are required to bring it up to code and install a handle tie. Existing multiwire circuits are grandfathered in under previous codes. Any new circuit will likely require an AFCI which cannot be used on a multiwire circuit unless to use a two pole AFCI breaker.
 
  #16  
Old 05-26-24, 11:15 AM
D
Member
Thread Starter
Join Date: Jul 2005
Location: Chicago land
Posts: 733
Received 1 Upvote on 1 Post
BTW. Here is a picture of the breakers I have, Q115 (and 20A variant)




 

Last edited by destruct05; 05-26-24 at 11:40 AM. Reason: did not upload
  #17  
Old 05-28-24, 10:19 AM
D
Member
Thread Starter
Join Date: Jul 2005
Location: Chicago land
Posts: 733
Received 1 Upvote on 1 Post
So, when is an ARC fault breaker required these days? I looked at double-pole version for my shared neutral wiring. Seems rather pricey:
https://www.lowes.com/pd/Siemens-QP-...1453c682c174d8
 
  #18  
Old 05-28-24, 01:33 PM
2
Member
Join Date: Jan 2014
Location: USA near Boston, MA
Posts: 2,331
Received 397 Upvotes on 346 Posts
According to the electrician doing my renovation in a 1912 house with a lot of electrical added since it was built:

Completely new circuits require AFCI protection. He is using breakers for those.
Additions to existing circuits require AFCI protection of the new wiring. He is using AFCI receptacles at the last location on the existing circuit to protect new wiring extended from there.

BTW my house had original knob & tube wiring that was all disconnected and replaced by new wiring over the years so there none of that to be dealt with in the renovation areas other than cutting out dead wires that are exposed by demolition.
 
  #19  
Old 05-28-24, 07:02 PM
D
Member
Thread Starter
Join Date: Jul 2005
Location: Chicago land
Posts: 733
Received 1 Upvote on 1 Post
thanks. I will opt for some ARC faults. Is it correct to assume that getting a double-pole breaker for my shared neutral setup is equivalent of buying two breakers and putting a tie bar on it?
 
  #20  
Old 05-29-24, 06:49 AM
2
Member
Join Date: Jan 2014
Location: USA near Boston, MA
Posts: 2,331
Received 397 Upvotes on 346 Posts
a double-pole breaker for my shared neutral setup is equivalent of buying two breakers and putting a tie bar on it?
​​​​​​​That is correct.
 
destruct05 voted this post useful.
 

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