We recently had an electrician in to wire our attic which is being converted to a bedroom, and then rewire the rest of the top floor. After reading through this site for the last few days, I'm coming up with questions that I wish I had thought of before the rewiring project began.

First of all, all of the upstairs (3 bedrooms, bathroom, tv room and attic bedroom) are run off of two 14-3 wires (3 circuits). I did ask him if this was going to be too much of an overload. He told me that it's not too much because not everything will be in use at the same time, but we have 3 kids and I know the rule of thumb is around 8 outlets/lights per circuit, and given that there are approximately 35 outlets and lights on these 3 circuits, I get the feeling that this may be a problem down the road. What should I do here, feed in another line from the panel and split some of the outlets and lights onto another circuit?

Second of all, everything has been done with 14-2 and 14-3 wiring and 15-amp circuits (the kitchen hasn't been rewired yet, but basement has), but I see that many people are recommending 12-2 with 20-amp circuits. Should I consider re-doing all of what has been done so far, or just keep what is done and of course make sure the kitchen is done with the required separate 20-amp circuits and 12-2 wire and consider doing the downstairs all on 12-2 and 20 amp?

Think that's all of my questions for now, sorry for the long post.

Many thanks!

 

jacobya,

Without actually seeing the addition or work being done it is sometimes difficult to determine what electrical installation is going to best serve the customer. I am under the assumtion that all permits are in place and that you are using a licensed and insured electrician as may be required in your area. With regards to the 14 gauge wire being used for general lighting circuits, this is completly acceptable and within code guidelines in our area. You would need to verify this with your local juristiction as there are some areas that do not allow 14 gauge wire to be used in residential applications. Not knowing the square footage of the addition It is difficult to determine if the two 14/3 multi-wire branch circuits would be sufficient. Two 14/3 cables would allow the installer to supply power to the addition with four (4) 15 amp circuits. My one concern with using 14/3 to supply power for the bedrooms is as follows: In our area we are required by code and the local authority to protect all devices such as receptacles, switches, smoke detectors and such with an AFCI ( Arc Fault Circuit Interupter) breaker. It is not possible to correctly install an AFCI breaker using a 14/3 cable as the shared neutral does not allow for proper operation of these breakers. We typically run a single 14/2 for each AFCI circuit. The receptacle in the new bathroom should be GFCI protected and on a 20 amp bath circuit and this should be wired using 12 gauge wire. All kitchen receptacles are required to be GFCI protected and on a 20 Amp circuit using 12 gauge wire. Although the NEC (National Electrcial Code) states that branch lighting circuits may be calculated at a rate of 3 volt/amps (watts) per square foot keep in mind that wiring to code represents the minimum requirements. Using 3 va per square foot would allow an electrician to use one 15 amp circuit per 600 square feet of heated space. We generally use a rule of thumb of 10 -12 devices per circuit depending upon the use anticipated. I hope that I have given you some information that may be of some help.

 

If you are rewiring, then the upstairs must be brought up to code.

That means that the bathroom must get a dedicated 20 amp circuit.

That means you have three bedrooms left to wire. They need to be AFCI circuits. I would recommend two or three 20 amp circuits for those bedrooms.

 

Thanks guys, I read about the requirement for AFCI breakers for all of the bedrooms, and I checked and there are definitely no AFCI breakers in the panel anywhere. I'm in Canada and I know it is code for bedrooms here as well. Man, I wish I had done my research beforehand, but I guess I made the assumption that a licensed electrician would be able to rewire the house properly, and yes there was a permit taken out for the rewire as it was done in conjuction with the panel upgrade. I'm very frustrated, but I guess it could be worse, I haven't put up any drywall yet, but I do have insulation and a vapour barrier up so it's not going to be a simple rewiring job.

So I guess this means I'm going to be pretty much redoing everything this guy has already done upstairs? What is the best approach here, run a single 20amp circuit to each room and put AFCI in for each bedroom? Also, I plan on having a small workshop in the basement, and he wired that area with 14-2 on a 15amp breaker as well, should this be switched over to 12-2, are there any special requirements for the basement?

Many thanks for all of your expert advice

 

In Canada the codes are very different than NEC.
For bathrooms
The code does not require a separate circuit for bathroom receptacles. Bathroom receptacles can be supplied by a general purpose circuit that supplies other general purpose receptacle and lighting outlets. Multiple bath and washrooms are permitted to be supplied by the same circuit.

In bathrooms where heavy loads such as hair dryers may be used it is recommended not to combine multiple bathrooms on the same circuit.

General outlet rules
The Code permits up to 12 general purpose outlets and fixtures on a general purpose 15 amp circuit based on an assumption that the average load per outlet will not exceed 1 amp.

For light fixtures
Where the load is known the Code permits more than 12 outlets on a 15 amp circuit provided the total load current does not exceed 12 amps. In this case each fixture will draw 60 watts or .5 amps for a total load of 20 x .5 amps = 10 amps, which is below the 12 amp maximum.

The above assumes the marked maximum lamp size on the fixture is 60 watts; if the marked maximum lamp size is larger, then the marked lamp size will have to be used in the calculation.

No other loads shall be connected to this circuit.

This info and more comes from The Electrical Inspection Authourity of Ontario FAQ section.
http://www.esainspection.net/business/faq.php

 

Don't mean to step on any toes, but that seems exessive to me. Could you explain why you recommend over sizing the circuits like that that?

 

I always suggest 20 amp circuits when adding new circuits or rewiring. 20 amp circuits can carry more load and are less likely to trip from an overload.

As for why I suggested two or three, I find it a good idea to have more than one circuit feeding a bedroom. In this way you can use two high current devices in the same room without tripping the breaker. Whether I went with two or three circuits would depend on how big the rooms are and if there is the possibility that one room might be used as an office.

When I made my original answer I talked about NEC requirements. The original poster lives in Canada, so the NEC does not apply. joed has discussed Canada's codes and how they differ from the US codes. Another difference is that 20 amp circuits must have 20 amp receptacles. Depending on the number of receptacles and anticipated use of the rooms, I might be tempted to reduce the circuits for the bedrooms to 15 amp if I went with three circuits, to allow 15 amp receptacles to be used.

 

Thanks

 

Thanks a lot to everyone for all of the feedback. I think I'm going to try and trace through the circuits that have been laid out so far and figure out how he has the 14-3 wires divided up between all the rooms upstairs and then ask some more questions on the best way to reconfigure everything. Either way, something is going to have to change because the current configuration won't allow for AFCI breakers in the upstairs bedrooms, correct?

Does this approach make sense: 15 amp circuit for each bedroom upstairs, as each currently has one light and 5 or 6 outlets and is already wired with 14 guage wiring. I'll then put these all on AFCI breakers. For the bathroom a separate 20-amp circuit and for the new bedroom in the attic, two 15-amp circuits as I have a powered roof vent, whole home fan, 7 or 8 outlets and 7 recessed lights and a smoke detector up there (lights and the whole home fan on one circuit, and the roof vent and the outlets on the other?). And for the downstairs, one 20-amp circuit for each room?

Thanks for your advice

 

Pretty much, except the kitchen.

 

AFCI breakers are most definitely available in two-pole configurations.
Feeding a 14/3 from an AFCB is not a problem.

 

I don't think lighting is allowed on 20 amp circuits in Canada.
If you install 20 circuits you MUST use 20 amp receptacles. The T slot type are good.

 

So do you think I would be just better off sticking with a 15-amp circuit for each room (outlets and lights)? Also, can I use 12-2 wire on a 15-amp circuit?

 

Since the work is already done, if it meets code, you should only re-rewire if you've got dimming lights, tripping breakers and so on.

In the NEC, yes, you can use 12-2 for a 15A circuit. You should take precautions to ensure that future additions are not made with the assumption that the 12 AWG wire means it is a 20A circuit.

For example I rewired my house entirely in 12 AWG for 15 and 20 amp circuits. I then had a new service panel installed and gave the electrician a chart showing which numbered wires were 15A and which were 20A. Nonetheless he put all the 12 AWG wires on 20A breakers because I did not verbally tell him about this fact. File under "nobody reads the directions."

 

There is absolutely no reason to use a 15 amp breaker when all #12 is used (other than voltage drop). There is no "extra" 5 amps when a 15 is used, just a wasted 5 amps of available capacity.

There is NO safety gain in using a 15 on #12 wire. It ONLY serves to confuse a future worker.

 

You are right of course. Outside the scope of my original post was that I had two short sections of 14 AWG in walls that I did not get around to replacing until some time after the new service was put in.

Other rewiring done by previous owners also used 14 AWG, and since I plan to replace that with #12 when we remodel those areas, I used #12 to a distant junction box to feed those circuits rather than buy rolls of #14 for which I had no future use.

 

Remember that the original poster is in Canada. To have a 20 amp circuit in Canada, all the receptacles must be 20 amp receptacles.

 

Just a few comments ( from an electrical contractor...Not a Moderator )

Not sure where that rule of thumb came from but the NEC does not mandate how many outlets/luminares are on a circuit so we have to calculate that and I will say as a contractor if I had a rule of thumb like that I would have far to many circuits in my panels.

We try to not put more than 12-14 items on a 15A or 20A circuit as OUR rule...and I have been doing this for 17 years...and have not EVER had a problem and wired THOUSANDS of homes. ( ie: maybe 2 bedrooms ( small ) with total 10 recepts and 2 lights for a total of 12 items works out JUST fine if you ask me.... ( remember voltage drop is not really a major concern if centrally wired correctly...and again VD is not a NEC rule...only a suggestion for efficient operation )

Also......choosing to run 12 AWG versus 14 AWG has to be a personal choice because as a EC my opinion is 14 AWG is fine on bedroom circuits and where applicable and should pose no issues. Is it better to run 12 AWG than 14 AWG...in my humble opinion NO....now if wiring your own house fine if you would like to do that but when bidding jobs and wiring homes for a living you generally use 14 AWG for bedrooms,halls,bathrooms,living rooms and all lighting and reserve 12 for Kitchens, Laundry, Dining, Bathroom Recps, outside GFCI *( *which is only really required to be 15 or 20A ) and well you get the picture.

Normal everyday use should not overload the circuit in the areas where 14 AWG is allowed......now the reason it is on Kitchens Counters and Washers and Bathroom Recepts and so on is due to known potential high level draws.....but as a contractor I am not spending the additional money for a house to be fully wired in 12 AWG....firstly it is a pain in the rear to work with...lol... and secondly in normal layouts where the electrician has ACTUALLY thought about what they are doing the panel location has been centralized ( sure not in all cases..but in all our cases..lol )

Ok......so thats my opinion on using 14 AWG or 12 AWG.....from a contractors standpoint....if the homeowner demands 12 AWG..no problem but it will reflect in pricing. If someone is wiring a bedroom and knows of a dedicated NEED the best course is to wire for that dedicated need.

Oh I forgot.....don't get me wrong as I agree 12 AWG has more capacity has less chance of overload and I am in no way discounting that but in bidding and pricing and general use it is in my opinion overkill for the examples listed.

Also I forgot...from a AFCI standpoint if you place (2) bedrooms of no more than lets say 12-14 items you get away with using only (1) AFCI for that circuit.... In most all cases we place the Smoke Detectors all on one ( it's own) AFCI circuit and then end it in the attic for expantion which is totally compliant since many seem to think the AFCI requirement can't leave the bedroom....these are things electrical contractors do on a daily basis..we are in the trenches doing it and have spent years figuring out the ways to do it and be safe.

The average bedroom has maybe (1) lamp, (1) Ceiling Light, (1) TV and maybe a Stereo and the other outlets are unused.....The number of items on a circuit is always changing depending on the specs of the actual house that is being wired and the addition as items being added.

 

Well said. From a homeowner's perspective:

A contractor buys wire constantly in large quantities and rolls off whatever is needed then moves on to the next job and uses up what's leftover.

However my leftovers sit in the basement and gather dust. For example if I needed 100 feet of #12 black ($20/500 ft) and 400 feet of #14 black ($15/500 ft), it made more sense to buy 500 feet of #12 black for $20. (My house is almost all raceway.)

Box fill requirements are more challenging with #12. The extra quarter inch adds up fast.

Using Backwired Spec Grade devices mitigates the added difficulty of working with #12.

Using #12 everywhere makes it easier to change your mind, something DIYers like me are known to do.

Qualified personnel should know better than to rely on wire size to determine the amperage of an existing circuit. For example my A/C condenser is wired with #10 on a 40A HACR breaker. As of the 1999 code cycle that was OK and passed inspection.

 

So it's alright to have a smoke detector on an AFCI circuit then? I thought someone mentioned they weren't supposed to be? If it's alright, then the way things are wired right now might be alright. I'll have to clarify with the electrician exactly how things are connected, but the way you're explaining things ElectricalMan, everything might be alright, as long as I put in two double-pole AFCI breakers for the circuits that are handling everything upstairs.

 

According to the NEC, a bedroom smoke detector must be on an AFCI circuit. But may localities have amended this requirement, so you have to check locally to see if it is required. But it's not prohibited.

 

The OP is in Canada. Quoting NEC does not apply. The codes are much different in Canada.

There are limits to the number of receptacles allowed on a circuit. 12 outlets on a 15 amp circuit.
Bathrooms do not have to be on dedicated circuits. They don't have be 20 amp either.
Lights do have to be on 15 amp circuits.
Receptacles must match the circuit size. No 15 amp recepatcles on a 20 amp circuit.
The code does NOT permit smokes to be on AFCI. That is Smokes must NOT be on AFCI circuits.

 

I have to ask.
Does Canada have an overwhelming number of appliances with 20 amp plugs on them?
I just don't get this silly code. Other than a large power tool I have never seen anything with a 20 amp plug in a home.

 

No, but that is not the point. The point is the code wants it that way, it is not our place to judge.

Considert that kitchen counter circuits in Canada are multiwire 15A, rather than 20A single in the USA.

 

See, here I disagree. It IS our place to judge and question. This is how and why codes change every three years. If enough people complain and question a code the CMP may take a deeper look into it and consider a change.
In the real world manufacturer lobby groups do hold just a bit more water, unfortunatley. Why do you think AFI's got shoved down our throats before the technology was perfected.

Just like I strongly disagree with both allowing 15 amp, and requiring split/multi-wire at kitchen counters. Both are absurd codes IMO!
For the US, the two 20 amp circuits are IMO not just code but the absolute bare minimum.

 

Kitchen counter now allows dedicated 20 amp counter receptacles in place of split 15 amp circuit. I think this was mainly changed to allow GFCI to be used within 1 meter of sink. But you need the 20 amp T slot GFCIs. Only the receptcles within 1 meter of sink need GFCI not all counter receptacles.

 

Just curious what the reasoning behind that is, I know very little about any of this stuff, but if AFCIs are safer, why would they be prohibited on a circuit with a smoke detector? That being said, if the electrician wired all of the bedrooms, bathroom and smoke detectors on 2 14-3 wires (which I think is on 4 15-amp breakers?), do I have a problem installing the 2-pole AFCI breakers, in other words, do I have to run a new line specifically for the smoke detectors?

 

From the replies of the Canada folks here it would seem so.

 

Just baseless speculation here: The primary purpose of an AFCI is property protection. Life safety is a byproduct of the AFCI, aka a secondary purpose. On the other hand a smoke detector's primary purpose is life safety.

If the AFCI should malfunction or have a "nuisance" trip, the smoke detector may not work, thereby impairing its life safety function. Since life safety is the highest-order priority in just about any situation I can think of, the AFCI is not permitted.

 

so what amperage of light switches do you use? Standard 15A ones could over heat right, unlike 15A recepticles that are rated at 20A for passthru?

 

> so what amperage of light switches do you use?
15A.

> Standard 15A ones could overheat
No. Why?

> unlike 15A receptacles that are rated at 20A for passthru?
A 15A snap switch simply burns out faster if used to switch a 20A load.

You can use a 15A snap on a 20A circuit.
Just don't put more that a 15A load on any one switch.

Usually a lighting circuit feeds many switches each serving only an amp or two load. 15A is quite generous.

 

I guess I thought a 15A switch on a 20A circuit would require the switch to have a feedthru rating of 20A ... but what you are saying as the current(amps) thru the switch depend on the device, so it is not like the switch is seeing 20A, it just sees the load of the light (small)... so since I pulled 12-2 in bedrooms I could have used 20A AFCI's for my 15A recepticles and 15A switches ... now I get why someone suggested not having any 15A circuits ... thanks for your help.

 

What bolide said.
General snap switches are rated for the load they serve, not the circuit size they are on.

 

For most circuits you want the breaker to cut off if there is an electrical fire, especially in bedrooms. The smoke detector circuit you specifically want to stay ON if there is a fire.

 

Im no expert, but I agree with the post about using gfci.
It can't share a neutral, and will cause you problems.

First house I lived in I upgarded/rewired from 14 to 12. You cant ever have too big a wire, and the cost is minimal. If you pay someone to do the work, the labor is probably going to far outweigh the cost of the difference from #14 to #12 wire.

WHile ti's true that most lighting circuits are 15 amp (and while you'll find few if any 20a rated light switches), the fact of the matter is many circuits include more than just lights. And when you get into 3 wire combos, it just causes more confusion.

The new house I live in, seem everything is 3 wire (thankfully all is 12), splitting circuits here and there. Fine and dandy in some cases, but causes me troubles when the washer, kitchen and bath aren't on gfci, and I have to revamp for them all.

 

Did you have to bring that up so soon again??
No, 15A switches are fine on 20A circuits. The only restriction is that they mustn't switch more than 15A. It's not like they will fry on a 20A circuit.

 

oops sorry, didnt catch it was brought up.
Yep, a 'lighting' circuit means just that... it includes lights, which overall, don;t add up to very much amperage... unless of course your running a gazillion lights.

also, a note on the smoke detector circuit. while it's fine n dandy to have a 24 hour power source without worry about batteries, you should still keep your smoke detectors backup battery fresh.

 

RpmQ,
About multi-wire (shared neutral) circuits. While it may be a bit more confusing to the DIYer, it is far easier for the professional.
They save wire, save labor, save space in the panel, reduce wire bundling and reduce voltage drop.
I use multi-wire home runs whenever possible. The fact that a DIYer or another professional may be confused later on is really not a concern to me. They are legal, safe and easy to work with, if you know what you are doing.

And as I said many posts back, both AFCI and GFCI ARE available in two-pole, 15 & 20 amp versions, and most definitely CAN be used on multi-wire circuits.