THHN double the price of Romex?

[VietGnome]

I'm by no means any electrician, but I know a few, as well as a couple very competent DIYers. I'm just trying to research and learn as much as I can so I have a decent knowledge of the process and can do as much myself as possible. DIYing my own 30x40 stick build this summer, and I feel I have quite a good grasp on the entire build, but the electrical has always been the biggest "unknown" in a way. I've done tons of research, planning, etc to determine what I needed to run a 125A feeder, sub panel, and power all my circuits with in wall romex. I have a pretty good grasp of the overall scheme and what needs to be done, but obviously have lots of code specific questions and planing issues to work through as I go.

Felt like I had quite a good grasp on things with a codebook in hand, and a very handy FIL. Turns out New Brunswick has extremely strict electrical permit regulations (that's a whole other story, and kind of crazy if you've seen the majority of build quality throughout the province). Trying to figure out the process and get all my eggs in a row, I somehow may have burned bridged with the electrician that is a close friend of my wife (again - another story).

Regardless, without help, I'm considering the possibility of surface mounted EMT, instead of in wall romex. Still trying to go through everything in CEC regarding if my ground should be bare, or jacketed, what size of EMT I need for various circuits, etc, etc. It's also my understanding that as per CEC you can't put cables like NMD90 in conduit, you need individual conductors. Now my issue is, T90 (THHN) is essentially double the price of NMD90.

Example: 150m of 14/1 T90 is $108. Meaning 150m of 2 conductors 1 ground would be $324.

Meanwhile 150m of NMD90 is $185.


Previously I found that calling around to electrical distributor shops in the area got me significantly better prices than the big box store (surprise surprise), however they scaled the same. So before I spend another chunk of time calling all over hells half acre getting prices on wire, does this track? Should I be expecting to spend significantly more on single conductors? I was under the impression that it would be cheaper.

 

[wyliesdiesels]

Im in the US so cant help but am curious about the differences between canada and US code

 

[sparky 1971]

It's the way it is. I just checked my pricing at the local supply house for 14 gauge. THHN/THWN stranded is $85 for a 500' spool and 14/2 NM is $105 for 250'. I couldn't find a 500' spool of Romex, so two 250' coils would be $210 and three spools of THHN is gonna run $255. I'm also going to add that if I'm doing the job with EMT, I won't be pulling a ground wire so there's that, but I have no clue whether or not that's allowed in Canada.

 

[dscheidt]

It's the way it is. I just checked my pricing at the local supply house for 14 gauge. THHN/THWN stranded is $85 for a 500' spool and 14/2 NM is $105 for 250'. I couldn't find a 500' spool of Romex, so two 250' coils would be $210 and three spools of THHN is gonna run $255. I'm also going to add that if I'm doing the job with EMT, I won't be pulling a ground wire so there's that, but I have no clue whether or not that's allowed in Canada.

solid thhn should be a few bucks cheaper, and with 12 and 14 awg not really any harder to deal with.

If you don't have to, do not pull a ground wire, the conduit is a sufficient ground path. In a short to ground, the conduit has so much surface area its impedance is much lower than the wire, and will carry the fault current for the half cycle it takes for the breaker to trip. So a ground wire is just a waste of time and money.

 

[cybrdyke]

Wire prices can swing wildly in either direction at any time, mostly because copper is a traded commodity (but also for a whole slew of other reasons). The large disparity that you're seeing right now is likely the result of this. If your supplier bought NM at one point when copper prices were low and then bought THHN at another point when copper prices were higher, this could explain the result. If this were to happen, most sellers will raise the price of the NM to reflect the higher cost of copper, so that the disparity is more normal. The exception to this is the big box stores, who dont seem to have the ability to do this. That explains why there are times when the big box is cheaper than the supply house, and vice-versa.
CD

 

[theoldwizard1]

It's the way it is. I just checked my pricing at the local supply house for 14 gauge. THHN/THWN stranded is $85 for a 500' spool and 14/2 NM is $105 for 250'. I couldn't find a 500' spool of Romex, so two 250' coils would be $210 and three spools of THHN is gonna run $255.

You are doing your "math" backward. A 500' spool of stranded THHN/THWN would yield 250' of hot and neutral, with no ground. Add a bare copper wire or metallic conduit and you will be way more than $105 for the NM-B !

 

[The Cobbler]

All I know is In Canada you can pull short lengths of romex in conduit. not sure if there's a limit to the length tho

 

[Cruzan80]

You are doing your "math" backward. A 500' spool of stranded THHN/THWN would yield 250' of hot and neutral, with no ground. Add a bare copper wire or metallic conduit and you will be way more than $105 for the NM-B !

No, you don't get how he did the math. He was aiming for 500' comparables. One is $105x2 (14/2 roll of 250' X qty 2), the other is $85x3 (500' roll of THHN x qty 3). Buying by the foot is different pricing than bulk rolls.

 

[Dagny]

What is the inside going to be sheeted with?

 

[sparky 1971]

You are doing your "math" backward. A 500' spool of stranded THHN/THWN would yield 250' of hot and neutral, with no ground. Add a bare copper wire or metallic conduit and you will be way more than $105 for the NM-B !

I'm not doing anything backwards, you just can't follow along. In fact, I figured it the same way the OP did it so we have apples to apples. Three 500' spools of THWN is the equivalent footage (1500') of two 250' coils of NM-B. That's why I specifically said I couldn't find pricing on 500' coils. Aaaaaand, your'e short the neutral, that 500' spool of black #14 can't be cut in half and 250' of it magically becomes white. You also screwed up with the 14/2 by getting it by the foot at .55 per foot when a 250' coil is $130.00, or $.52 per foot.

 

[The Cobbler]

All I know is In Canada you can pull short lengths of romex in conduit. not sure if there's a limit to the length tho

from Google , for what its worth
Yes, you can pull Romex (NMD90/NM-B) in conduit in Canada, but it is restricted to dry, indoor locations and primarily for physical protection. The conduit must not be used in wet or damp locations, and you must respect conduit fill limits, as the cable jacket counts towards the capacity.

Key Requirements & Considerations:

• Dry Locations Only: Do not use Romex in conduit outdoors or in wet areas; it is only permitted in dry indoor locations.
• Protection Sleeves: Often used as a protective sleeve for exposed NM cable, such as going from a ceiling down to a panel or receptacle.
• Conduit Fill Limitations: Romex is hard to pull. Ensure you do not exceed 53% conduit fill for a single cable, or 31% for two, though many inspectors prefer leaving ample room.
• Derating: If you are running multiple cables through a long conduit, you may need to derate the ampacity of the conductors

 

[sparky 1971]

solid thhn should be a few bucks cheaper, and with 12 and 14 awg not really any harder to deal with.

Solid is cheaper but since all I use is stranded, it's easier for me to check pricing because I know the part #'s. I choose stranded because it's much easier to pull longer runs with no help. It also has it's down sides.

 

[VietGnome]

It's the way it is. I just checked my pricing at the local supply house for 14 gauge. THHN/THWN stranded is $85 for a 500' spool and 14/2 NM is $105 for 250'. I couldn't find a 500' spool of Romex, so two 250' coils would be $210 and three spools of THHN is gonna run $255. I'm also going to add that if I'm doing the job with EMT, I won't be pulling a ground wire so there's that, but I have no clue whether or not that's allowed in Canada.

It's allowed in Canada as long as it's a dry indoor location. I've also read lots of people say they also always run a ground as a redundancy regardless, so I'm still undecided on that.

All I know is In Canada you can pull short lengths of romex in conduit. not sure if there's a limit to the length tho

Interesting! I'll go back through the code and see what it says.

What is the inside going to be sheeted with?

Likely metal R panel.

 

[wyliesdiesels]

You are doing your "math" backward. A 500' spool of stranded THHN/THWN would yield 250' of hot and neutral, with no ground. Add a bare copper wire or metallic conduit and you will be way more than $105 for the NM-B !

You cant split a 500’ roll into 1 hot and 1 neutral because code prohibits phase taping any conductor under #4.

Try again.

 

[sparky 1971]

You cant split a 500’ roll into 1 hot and 1 neutral because code prohibits phase taping any conductor under #4.

Try again.

C'mon man, it's the wizard, he was trolling before Lincoln invented the internet; when being a troll usually involved living under a bridge.

And, I'd like for him to tell us what in the royal eff one is supposed to do with 250' of wire pulled off of a 500' spool, roll it up on a garden hose reel or just string it out on the floor? That's gonna make a helluva mess.

 

[Ultradog MN]

I never understood the hauteur of some of the guys who reply to electrical questions here...

To the OP, I always figured if I did the work myself and not hire an electrician I could go first class on all my componants and still save a bundle. That meant thinwall everywhere, 1900 boxes with mud rings instead of single handiboxes, 12 ga wire and 20 amp breakers and devices instead of 15 amp and 14 ga (though I did only pull 14 ga for the grounds)
I started at the meter socket at the house and ran a new 100A service underground to the garage and have four 240V and 4 120V circuits in here. I don't have reciepts for everything I bought to do it but a Swag would be in the $1500 range.
If I had hired the work done it would have cost 3 times that amount. So you don't need to skimp on everything.

 

[PCustoms]

And, I'd like for him to tell us what in the royal eff one is supposed to do with 250' of wire pulled off of a 500' spool, roll it up on a garden hose reel or just string it out on the floor?

Just pull it from both ends, duh!

 

[LOW1]

Im in the US so cant help but am curious about the differences between canada and US code

When we wired our Ontario boathouse our electrician did not put a grounding rod by the subpanel that was installed in it. Apparently detached structures with theIr own sub panels could not have separate grounding rods. Instead the grounds for the separate structures have to go back to the main panel in the primary structure and that is the only permitted ground.

The theory, according to the electrician, was that a fault or lightning strike could travel between multiple grounding rods and create a shock risk.

i Think this may have recently been changed, at least in Ontario.

I was used to the “more the merrier” U.S. approach to ground rods and never did understand the reason for this.

 

[VietGnome]

I never understood the hauteur of some of the guys who reply to electrical questions here...

To the OP, I always figured if I did the work myself and not hire an electrician I could go first class on all my componants and still save a bundle. That meant thinwall everywhere, 1900 boxes with mud rings instead of single handiboxes, 12 ga wire and 20 amp breakers and devices instead of 15 amp and 14 ga (though I did only pull 14 ga for the grounds)
I started at the meter socket at the house and ran a new 100A service underground to the garage and have four 240V and 4 120V circuits in here. I don't have reciepts for everything I bought to do it but a Swag would be in the $1500 range.
If I had hired the work done it would have cost 3 times that amount. So you don't need to skimp on everything.

I have it all planned out and anticipate it being quite nice. 125A service, 20A for outlets, no skimping, etc.

The main hurdle right now is where I live the only person that can apply for an electrical permit is a licensed electrician. Homeowner permits do not exist here.

 

[VietGnome]

When we wired our Ontario boathouse our electrician did not put a grounding rod by the subpanel that was installed in it. Apparently detached structures with theIr own sub panels could not have separate grounding rods. Instead the grounds for the separate structures have to go back to the main panel in the primary structure and that is the only permitted ground.

The theory, according to the electrician, was that a fault or lightning strike could travel between multiple grounding rods and create a shock risk.

i Think this may have recently been changed, at least in Ontario.

I was used to the “more the merrier” U.S. approach to ground rods and never did understand the reason for this.

Yeah I know Ontario has it's own building code, not sure about electrical.

I believe the CEC states separate structures require 1 or 2 grounding rods with a ground in the feeder running back to the main panel.

 

[The Cobbler]

CEC states separate structures require 1 or 2 grounding rods with a ground in the feeder running back to the main panel.

in 2016 or 17 I built a detached garage at home. complete with electrical and ground rods weren't required.

 

[VietGnome]

in 2016 or 17 I built a detached garage at home. complete with electrical and ground rods weren't required.

Oh for sure, I'm not doubting ya. Does Ontario have its own electric code like it does building code?

I've only read the 2021 CEC, so it could also be a change in those 4-5 years.

 

[The Cobbler]

Hydro One did the inspection . I don't know what codes we use.
I used a colleague electrician , I was his helper

 

[theoldwizard1]

You cant split a 500’ roll into 1 hot and 1 neutral because code prohibits phase taping any conductor under #4.

Learn something new every day !

 

[LukeOresk]

From the 2021 Ontario masters course

Ontario has its own code electrical code

 

[wyliesdiesels]

Apparently detached structures with theIr own sub panels could not have separate grounding rods. Instead the grounds for the separate structures have to go back to the main panel in the primary structure and that is the only permitted ground.

which makes no sense. grounding electrodes are for shunting lightning. better to have them at the detached than force the surge to travel on the EGC back to the main building and use the rods there

 

[LOW1]

which makes no sense. grounding electrodes are for shunting lightning. better to have them at the detached than force the surge to travel on the EGC back to the main building and use the rods there

I agree with you. I found it very strange that the US and Ontario could have two directly opposite views on this.