Residential Wiring

[Jimmy7]

I'm sure this topic has been kicked around before. I believe there is no maximum number of receptacles you can put on a 15 amp circuit in a residential dwelling, correct? With that being said, I was curious how many receptacles you prefer to put on a 15 amp circuit when you're roughing a house, what's your rule of thumb?
Do you keep your lighting on separate circuits, or do you combine lighting and receptacles together?

 

[Besoeker3]

I'm sure this topic has been kicked around before. I believe there is no maximum number of receptacles you can put on a 15 amp circuit in a residential dwelling, correct? With that being said, I was curious how many receptacles you prefer to put on a 15 amp circuit when you're roughing a house, what's your rule of thumb?
Do you keep your lighting on separate circuits, or do you combine lighting and receptacles together?

I'm British. For us we have have one lower floor lighting and another for the upper floor. This is typical for residences.

 

[marmathsen]

I'm sure this topic has been kicked around before. I believe there is no maximum number of receptacles you can put on a 15 amp circuit in a residential dwelling, correct? With that being said, I was curious how many receptacles you prefer to put on a 15 amp circuit when you're roughing a house, what's your rule of thumb?
Do you keep your lighting on separate circuits, or do you combine lighting and receptacles together?

We never do general use receptacles on 15A circuits. We almost never combine lights and receptacles. No hard fast rule for us but we won't typically do more than about 8 receptacles on a circuit. Dedicated for each bedroom. We only do residential. Part of our rationale for this is early on in our company we had a job we wired that ended up having space heaters in their bedrooms and were constantly tripping circuits.

Rob G - Seattle

 

[nizak]

Lighting is on 15 amp circuits. Generally end up with 4 lighting circuits total. Most homes I do are 3-4K sq ft.
Once all the lighting is in place I will load check each circuit and 90% of the time would be able to consolidate and end up with 3 circuits . Saving $7 on a breaker doesn’t interest me. Usually have no more than 5-7 amps per circuit.

General use receptacles are always on 20 amp circuits and most times end up with 10-12 per circuit.

The heaviest load is usually a vacuum cleaner on any G.U. receptacle.

It’s easy to end up with some long branch circuits with the chopped up floor plans and structural beams to navigate.

I have never had a call back due to circuit overloading when wiring receps with #12.

I have had service calls on newer built homes where receps were wired with #14 and circuits were overloading.

It’s not at all uncommon to come across as many as 15-20 receptacles on one 15 amp circuit.

We’ve got several residential guys around here that are bare minimum types.

And that’s fine, I’m just not one of them.

 

[augie47]

As an inspector I had plenty of homeowner complaints when they tripped breakers when using their exercise machines in bedrooms while someone was vacuuming (or such). Shame as these were often 500k+ homes with 15+ receptacles on a 15 amp circuit and multistory making new circuits practically impossible.
Low bid electricians, no GC requirements

 

[Seven-Delta-FortyOne]

There is no Code maximum, but there is certainly best practice and experience.

I use very few 15 amp circuits, and when I do, it’s lighting only. I never put receptacles on 15A circuits.

I’ve done some places where each bedroom got its own 20A circuit, lights and receps combined, as space heaters were anticipated, but generally I like to keep them separate, so when the HO plugs in their space heater and electric blanket and a few toys all at once, and trips the breaker, they aren’t also in the dark, , but that’s not a Code requirement.

I try to use experience and common sense. I will put at least 2 circuits into garages, I never combine bathroom receptacles, each bathroom gets its own circuit, etc.

 

[nizak]

There is no Code maximum, but there is certainly best practice and experience.

I use very few 15 amp circuits, and when I do, it’s lighting only. I never put receptacles on 15A circuits.

I’ve done some places where each bedroom got its own 20A circuit, lights and receps combined, as space heaters were anticipated, but generally I like to keep them separate, so when the HO plugs in their space heater and electric blanket and a few toys all at once, and trips the breaker, they aren’t also in the dark, , but that’s not a Code requirement.

I try to use experience and common sense. I will put at least 2 circuits into garages, I never combine bathroom receptacles, each bathroom gets its own circuit, etc.

We have around 10 contractors in this area that do mainly residential work.

At least half of them do what I would say is sub standard work.

It meets bare minimum code. It fails miserably on workmanship but that’s difficult to enforce.

The high volume builders love these guys. They charge about $4 / sq ft . I don’t know how they do it.

 

[Seven-Delta-FortyOne]

I’m very glad that my niche is custom. It can certainly be stressful at times, dealing with picky customers and the entailing emotional aspect to a project, but I still think that beats a race to the bottom that production building is.

 

[TX+ MASTER#4544]

Section 210.11 Branch Circuits Required 210.11 (A) Number of Branch Circuits and (B) Load Evenly Proportioned Among Branch Circuits.
This determines how many circuits you will need using 15 amp or 20 amp circuits for your general lighting load.

If you have an electrical license and have some experience then it's up to you to decide.
Check the titles to those Sections mentioned above. And your calculated load.

This will be your general lighting load and not other circuits that are required by Code such as 2 small appliances branch circuits and laundry branch circuit(s) and bathroom branch circuit(s).

Qualified and licensed electricians will know how to determine the number of outlets on a given circuit.

Thanks for reading
Comments accepted
TX+MASTER#4544

 

[don_resqcapt19]

Section 210.11 Branch Circuits Required 210.11 (A) Number of Branch Circuits and (B) Load Evenly Proportioned Among Branch Circuits.
This determines how many circuits you will need using 15 amp or 20 amp circuits for your general lighting load.

If you have an electrical license and have some experience then it's up to you to decide.
Check the titles to those Sections mentioned above. And your calculated load.

This will be your general lighting load and not other circuits that are required by Code such as 2 small appliances branch circuits and laundry branch circuit(s) and bathroom branch circuit(s).

Qualified and licensed electricians will know how to determine the number of outlets on a given circuit.

Thanks for reading
Comments accepted
TX+MASTER#4544

What are you trying to tell me with that post? As others have repeatedly said, there is no limit on the number of receptacles on a dwelling unit branch circuit.

 

[BarryO]

I never combine bathroom receptacles, each bathroom gets its own circuit, etc.

When we moved into our former house in '89, the receptacles in both bathrooms and the outdoor receptacles were on the same circuit so that only one GFCI was needed. After the first time hunting for what was the cause of the GFCI trip, that got changed right away.

 

[Rick 0920]

In Florida, we can use #14 for lighting and receptacles in the areas not specified in the NEC that require 20 amp branch circuits. Local jurisdictions may have special requirements. In Orlando, for instance, back in the 80's they limited you to (6) receptacles or (10) lights or a combination of (8) receptacles and lights. Now some custom homes that I did you might have (2) lights on a circuit if they were chandeliers with several lamps. We never loaded circuits very heavy. Today it's a different story. With expensive AFCI and GFCI and dual function breakers, some contractors are loading circuits heavier to cut down on the number of these breakers needed. While there is no specified number of receptacles per circuit, there is a minimum number of branch circuits required based on 3 va per sq. ft., 120v x rating of branch circuit. (breaker size) NEC Art 210.11 (B) does require that the installer evenly distribute these loads between the number of branch circuits.

 

[nizak]

In Florida, we can use #14 for lighting and receptacles in the areas not specified in the NEC that require 20 amp branch circuits. Local jurisdictions may have special requirements. In Orlando, for instance, back in the 80's they limited you to (6) receptacles or (10) lights or a combination of (8) receptacles and lights. Now some custom homes that I did you might have (2) lights on a circuit if they were chandeliers with several lamps. We never loaded circuits very heavy. Today it's a different story. With expensive AFCI and GFCI and dual function breakers, some contractors are loading circuits heavier to cut down on the number of these breakers needed. While there is no specified number of receptacles per circuit, there is a minimum number of branch circuits required based on 3 va per sq. ft., 120v x rating of branch circuit. (breaker size) NEC Art 210.11 (B) does require that the installer evenly distribute these loads between the number of branch circuits.

In 30 years I have never seen an inspector take time to determine the number of openings on a circuit.

Also, I’m not saying they should have to.

 

[nizak]

Has anyone had an inspector use a meter to check for branch circuit V.D. ?

I don’t believe it’s enforceable even if the percentage is greater than 3-5%

 

[Rick 0920]

Has anyone had an inspector use a meter to check for branch circuit V.D. ?

I don’t believe it’s enforceable even if the percentage is greater than 3-5%

Voltage drop is a Fine Print Note or Informational Note they call it now. Not enforceable codes. A good inspector would advise a less knowledgeable electrician at the time of inspection that he should consider pulling a larger conductor.
.

 

[Rick 0920]

In 30 years I have never seen an inspector take time to determine the number of openings on a circuit.

Also, I’m not saying they should have to.

There used to be a code section in Art. 90 that said a local jurisdiction would supersede the NEC if it were more stringent than the NEC section. That was in place at the time that I wired homes in the 80's. I've had several inspectors count openings on a circuit.

 

[Eddie702]

I used 15 amp for everything unless 20 a is required. I mix lighting and general use receptacles on a 15 amp circuit. If one circuit goes out you still want something live from a other circuit in every room so mix it up. I used to keep the number of receptacles and lighting outlets to 10 on a 15 amp circuit give or take 1 or 2

I don't agree with a circuit for each room. The circuit goes out you have nothing. I approach it like the small appliance branch circuits split between DR and kitchen.

 

[James L]

I rarely use 20 amp circuits if they aren't required. Occasionally I will, but is for something specific that I have in mind. Like one time I wired some retirement community duplexes and 4-plexes. I'm thinking the odds are pretty good that the residents might have an oxygen concentrator plugged in. Or space heaters. In those places, every room got a 20 amp circuit for the receptacles, and I had one lighting circuit throughout the whole unit.

But a run-of-the-mill house, bedrooms, living rooms, hallways and lighting throughout the house are wired the most convenient way to have 8-12 openings on a circuit. Convenient for me, that is, when I'm drilling holes and pulling wire.

 

[tortuga]

Voltage drop is a Fine Print Note or Informational Note they call it now. Not enforceable codes.
.

It says your an instructor in Florida, if I am not mistaken for the last decade (since 2014) its been in the FECC section C405.7.3 states that feeders are to be sized for a maximum voltage drop of 2%, Branch circuits are under FECC C405.7.3.2 are 3% so I would say its not accurate to say the Florida code omits voltage drop, its just not in the scope of the National Electrical Code to even address the topic so it went in a different code.

 

[VirutalElectrician]

When we moved into our former house in '89, the receptacles in both bathrooms and the outdoor receptacles were on the same circuit so that only one GFCI was needed. After the first time hunting for what was the cause of the GFCI trip, that got changed right away.

Both the town houses my mom has owned were wired the same way. Had to run downstairs every time she tripped the one upstairs.