50 amp breaker on a range circuit.

[John Kogel]

I found a 50 amp breaker supplying the electric range in a 1990 condo unit. I estimated the wire gauge to be #8 copper. I called for a repair by an electrician and was told that the electrician changed the breaker to a 40, which is what we normally see there. Good.
A couple of months later, I got to inspect another unit in the same building. Found the same issue in that panel, a 50 amp where we want to see a 40. Now I wonder if all the units were wired this way.
If so, does anyone know any way that this is acceptable?

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[Raymond Wand]

John

The data plate on the range would be the definitive answer. But 40 is common.

[H.G. Watson, Sr.]

John,

Were the ranges supplied of the "induction" type? Free-standing or slide-in? Which manufacturer?

If so, there is some play there (internal power supply controls, boost) vs. pure "resistance" type electric ranges (similar but not identical to AC condensors). Many require 40A minimum not max, some require 50A minimum, but the total kW rating is internally limited in continuous mode.
Example electrolux, and some differences for similar appearing models some listed for canada, some for US, some listed for both, some not; GE also.
Also, 208 or 240V? I recall you mentioned condo building.

[John Kogel]

HG, the ranges are standard 30" free-standing appliances with typical stovetop elements. They are both Camco units, similar to WCI or Frigidaire, and probably original to the building, 1995 or so.

I did notice both 50 amp breakers had cleaner lettering than the others, hinting that they may have been replacements.

Power is 120/208 (3 phase) in all likelihood*.
*Power is underground, and the meter vault was locked up, as usual. I am not licensed to do work in an electrical panel, and probing with a DMM is in all likelihood deemed to be 'work'. I don't go there. No access to appliance receptacles for voltage measurements, as usual. Could I measure voltage at the oven element? I've never tried that. Sounds like a half-baked way to do it.

I suspect the building maintenance person may have been performed some electrical repairs. Maybe there was a bad batch of 40 amp Commander breakers in the original build.

[Roger Frazee]

HG, the ranges are standard 30" free-standing appliances with typical stovetop elements. They are both Camco units, similar to WCI or Frigidaire, and probably original to the building, 1995 or so.

I did notice both 50 amp breakers had cleaner lettering than the others, hinting that they may have been replacements.

Power is 120/208 (3 phase) in all likelihood*.
*Power is underground, and the meter vault was locked up, as usual. I am not licensed to do work in an electrical panel, and probing with a DMM is in all likelihood deemed to be 'work'. I don't go there. No access to appliance receptacles for voltage measurements, as usual. Could I measure voltage at the oven element? I've never tried that. Sounds like a half-baked way to do it.

I suspect the building maintenance person may have been performed some electrical repairs. Maybe there was a bad batch of 40 amp Commander breakers in the original build.

If 75C terminations (that is most likely) #8 thwn or thhn copper is good for 50 amps when run in conduit as individual conductors.

[Jim Port]

In addition to Rogers comments, you will not find a 40 amp cord or receptacle for a stove. They are all 50 amp.

[Raymond Wand]

Norwood | Stove Cord Kit | Home Depot Canada
4 ft. 4-Prong Range Cord for Freestanding Electric Ranges-WX9X35GDS at The Home Depot

4 ft. 4-Prong Range Cord for Freestanding Electric Ranges-WX9X35GDS at The Home Depot

[Robert Schenck]

Jim ... Are you sure about not finding any "40 Amp Cords" ? Raymond provides some pretty good links ?

[Eric Barker]

In ranges such as in John's photo I turn on all the elements (cooktop and oven) simultaneously and leave them on for 2-3 minutes. More often than not, the 40 amp breakers will trip off.

[Jim Port]

Jim ... Are you sure about not finding any "40 Amp Cords" ? Raymond provides some pretty good links ?

Yes I am. Notice in this chart there is no 40 amp receptacle shown.

Nema Plug and Receptacle configurations

And we all know that the info available from the big box stores is correct too. Heck the person that put the link together most likely had no electrical knowlwdge.

[Jerry Peck]

A single receptacle installed on an individual branch circuit must have a rating of not less than that of the branch circuit.

The reason is that the branch circuit overcurrent device needs to trip off before the receptacle rating is exceeded and the receptacle burns up due to overcurrent through the receptacle.

Thus you are allowed to have a 50 amp receptacle on a 40 amp branch circuit with a 40 amp breaker, and you are also allowed to have a 50 amp receptacle on a 30 amp branch circuit with a 30 amp breaker, but you are not allowed to have a 30 amp receptacle on a 50 amp branch circuit with a 50 amp breaker.

"you are also allowed to have a 50 amp receptacle on a 30 amp branch circuit with a 30 amp breaker" Of course, though, you will not be able to use an appliance which draws 50 amps on that circuit as the 30 amp breaker will trip (unless, of course, it is an FPE ).

[Jerry Peck]

If 75C terminations (that is most likely) #8 thwn or thhn copper is good for 50 amps when run in conduit as individual conductors.

"If 75C terminations (that is most likely)"

In newer construction, yes, but not in older homes.

Roger (or Jim, Bill, Rollie, etc.), I am drawing a mental blank on trying to remember when the 75C terminations transitioned in, do you remember?

[John Kogel]

If 75C terminations (that is most likely) #8 thwn or thhn copper is good for 50 amps when run in conduit as individual conductors.

Thanks, Roger. Sorry for the shortage of info. This looks like NMD to me. I don't think it is run in conduit.

[Rollie Meyers]

If that is 8/3 NM cable then it needs to be sized in the 60 degree C column of table 310.16, which would mean 40A overcurrent protection, & it's OK for a 50A receptacle on a 40A circuit, since there are no 40A ones.

[Roger Frazee]

Thanks, Roger. Sorry for the shortage of info. This looks like NMD to me. I don't think it is run in conduit.

Nope it's not in conduit and I also didn't focus when I saw the 1990 dating. Jerry is likely correct that it would be 40 amps anyway.. I'm not up on the Canadian amperage rules. I'm assuming that nmd is the equivalent to our nmb in the USA. I'm not sure they require it to be 60C ampacity though I would suspect they would have nmd rated 40 amps if #8 copper.

Your load centers are sure different than ours ...

Jerry

I'll check I'm not sure when 75C started. I likely have it in a stored file ..if I can find it ..it is going to be like finding a needle in my haystack unless I identified the file as such.....

[H.G. Watson, Sr.]

There have been and continue to be significant distinctions and differences between requirements and certifications for products and methods between those in Canada and the US.

One can merely review the "requirements for equipment installations in ordinary locations" for both the U.S. and Canada as well as compare the distinctions and differences between ELBZ7 (Canada) and ELBZ paying special attention to those requirements for Power Supply Cord Kits and Power Supply Cords for both Ranges, etc. and Dryers to devine WHY same otherwise identical are often limited to lower amperage applications in Canada than in the U.S.

Although there have been of late significant advances (mostly changes in the certification standards and code language on the U.S. side) in the harmonization between the U.S. and Canada - the standards and certification requirements remain distinctly different overall.

However the OP has in a subsequent post that the system , interviening componants, and connection method thereto was not identified, (drawer not removed?) so at this point discussions surrounding branch vs. feeder, power cord kit and receptacle vs. power cord, are far-fetched. OP has also further indicated polyphase power (hmmm...) so the balance is moot.

Example, in the US we might allow 2-trade size reductions in both the N and G for such pwer cord kits or power cords Ranges & Dryers, this was and is not allowed for Canada, minimum sizes for same are expressed.

Perhaps some day, some of the posters here will realize Canada and its provinces are not goverened by U.S. standards, nor utilize NFPA 70, the "National" (as in the United States) Electrical Code, nor the same standards, certifications, etc. (which are not voluntary, as they are in the U.S.) for electrical equipment, componants, devices, etc.

[John Kogel]

Thanks, all. HG, a free standing kitchen range in Canada is 'always' connected cord and plug, so that it can be replaced at the whim of the consumer.
I post these situations to stimulate discussion, as we usually learn something from them.
FTR, I called for repairs in both cases and the tenants were advised to raise the subject with the tenants association.

[H.G. Watson, Sr.]

Thanks, all. HG, a free standing kitchen range in Canada is 'always' connected cord and plug, so that it can be replaced at the whim of the consumer.

JK, despite the prepared state the product may be required to be equipped with at time of sale; the certifications and standards, I do believe remain that same may be connected via power cord and not power cord kit-to-receptacle; from the terminal block to fused or unfused disconnect (following restrictions, instructions, certifications & CEC). If something has substantially changed in the last few months, regards your 'always' statement for all of Canada (i.e. not a local or provincial requirement); I would appreciate your reference to the change in the CSA standards, or part I or II; so that I might further investigate and update myself upon same.

I post these situations to stimulate discussion, as we usually learn something from them.
FTR, I called for repairs in both cases and the tenants were advised to raise the subject with the tenants association.

One thing to remember is that 'free standing' is inclusive, and in some ways misunderstood, as in practical and safe operation, for a tilt down door or drawer equipped device should be anchored (anti-tip provisions) for safety, and "slide in" installations as opposed to drop-in, are still floor-supported; and installations adjacent to cabinetry, fixed partions, etc. have restrictions, some of which are generic to the equipment classification/type, and some which are specific to the specific equipment and its certification.

Another is that the requirements, standards, etc. are distinctively different in the two contries as a whole, as there are distinctions and differences between provinces, states, and localities. And the distinctively different authority regarding the power supplier in areas Canada vs. US (rare municpal or government owned utilities in US per capita vs. Canada).

Finally there are distinctions with differences in type of occupancy classification and the type of power supplied, and the vintage of the original installation(s) and dates of modification.

[Jeff Keyeux]

In Canada, we have the Canadian Electrical Code (CEC) Part 1 which outlines "electrical safety requirements for wiring and equipment in buildings, structures, and premises, with the exception of mines, railways, aircraft, marinevessels, installations used for communication purposes, and automobiles"

Amendments which supersede these "minimum" requirements are made at the provincial and municipal levels. I happen to live in southwestern Ontario and as such, must refer to the Ontario Electrical Safety Code (OEC). Although the majority of the Ontario Safety Code is a direct reference to the CEC, there are some differences which need to be noted in specific areas of the code.

So, just as there are differences between the US and Canada, in Canada, there are also differences provice to province and in some cases, municipality to municipality. The bottom line is there currently isn't a universal standard that you can rely on for this type of information that crosses all geographical locations and certainly not between our two nations. There definitely are many similarities and I am sure that in some cases, the rules are the same since we have very similar systems and electrical design is based on common theory.

Having said this, I would like to comment on the original post from a Canadian (Ontario) perspective...

The Ontario Electrical Safety Code (OEC) specifies in subrule 26-744(4):
"Where a free-standing electric ragne, having a calculated demand of 50 A or less, is intended to be installed in a dwelling unit, a receptacle of CSA (Canadian Standards Association) Configuration 14-50R as shown in Diagram 1, shall be installed for the supply of electric energy to the appliance"

The receptacle referred to above is 50 amp, 125/250 volt rated.

Subrule 26-744(5) states:
"The receptacle required by Subrule (4) shall be permitted to be connected to a branch cirucuit rated at not less than 40 A"

This then leads one to determine the correct breaker size to be 40 amps even though the receptacle must be 50 amp rated by code.

However, although it should go without saying, that the wiring extending from the 40 amp breaker, must be rated for at least 40 amps the actual wiring used may be rated for more than 40 amps. In my area of the world, NMD90/Copper/#8 AWG cable is standardly used in combustible (wood) construction for ranges. It has an allowable ampacity as specified in Table 2 of the OECof 55 amps. This being the case, the OEC will allow a breaker size of up to 60 amps as indicated in Table 13 - "Rating or setting of overcurrent devices protecting conductors". However subrule 8-300(1)(a) "Branch circuits supplying electric ranges", has us consider a branch circuit supplying a range in adwelling unit to have a demand betweem8kW and 12kW which would be a current range of 33.3 amps - 50 amps.So, a breaker with a minimum of 40 amps (30 amps would be too small) and a maximum of a 50 amps would be installed. You would make the specific selection after looking at the intended appliance's wattage.*Note: Having said the above, it has not always been, that the temperature rating of cable used in combustible contruction has been 90 degree celcius rated as it is with NMD90. In the case of lower temperature ratings, the allowable ampacities are also lower. For example, 60 and 75 degree celcius rated cables have stated ampacities of 40 amps and 50 amps respectively. Therefore, you really must know the wire size, insulation rating and other specifics before you can simply install a breaker larger than 40 amps on a # 8 AWG cable for a range. Long story short, if a 50 amp breaker were installed on a range as in the scenario stated in the original inquiry, there wouldn't be an issue in changing it to 40 amps provided the connected range did not exceed 40 amps (9.6kW). However, it sounds as if the wiring methods may have been suitably designed for a 50 amp breaker in this multi dwelling building. That would remain to be determined by a fully qualified person...

[John Kogel]

Thanks, Jeff. I'm not sure what you said but it looks right.

Don, direct all Canadian questions to Jeff.

[Jim Robinson]

Well worth the four year wait.

- - - Updated - - -

Well worth the four year wait.

- - - Updated - - -

Well worth the four year wait.

[Jerry Peck]

Thanks, Jeff. I'm not sure what you said but it looks right.

Don, direct all Canadian questions to Jeff.

Jeff,

Just want to clarify what my understanding of what you you wrote: the CEC allows a 50 amp breaker to protect a 40 amp rated conductor ... or what did I miss?

[Jeff Keyeux]

To clarify, the CEC allows up to a 50A breaker on a 8/3 cable provided that its temperature rating affords it an ampacity of 50A or more (as specified in Table 2) as in the case of 8/3 NMD90. This is the cable type that is being installed in new construction. 8/3 cable installed in the past due to insulation rating may be rated for less than 50A and therefore not suitable for a 50A breaker.

[Dwight Doane]

To clarify, the CEC allows up to a 50A breaker on a 8/3 cable provided that its temperature rating affords it an ampacity of 50A or more (as specified in Table 2) as in the case of 8/3 NMD90. This is the cable type that is being installed in new construction. 8/3 cable installed in the past due to insulation rating may be rated for less than 50A and therefore not suitable for a 50A breaker.

OK - I have to poke some fun at this - Disclaimer - the following is for humor purposes only and not to be used as fact.

So it works this way - Aye

The exchange rate between Canada and the US allows for a higher amperage rating - Aye

you always get more for your money in Canada - Aye

Because it is colder in Canada the wires can handle more current - Aye

Because everything is Canada is better - Aye

isn't this right - Aye

[Jerry Peck]

To clarify, the CEC allows up to a 50A breaker on a 8/3 cable provided that its temperature rating affords it an ampacity of 50A or more (as specified in Table 2) as in the case of 8/3 NMD90. This is the cable type that is being installed in new construction. 8/3 cable installed in the past due to insulation rating may be rated for less than 50A and therefore not suitable for a 50A breaker.

Thank you for the clarification.

That is like down here where 8 AWG is rated for 40 amp with 60 degree C insulation, 50 amp with 75 degree C insulation, and 55 amp with 90 degree C insulation, with the governing factor additionally being that the rating of the equipment may rule. If the equipment is rated for 60 degree C, then 40 amp is all it is rated for even with 90 degree C insulation, likewise if the equipment is rated for 75 degree C (50 amp max even if 90 degree C insulation).

The rating is the lower of the insulation or the equipment.

[Rollie Meyers]

In the NEC, NM cable is used at the 60 degree rating even though it has 90 degree insulation.

[Jeff Keyeux]

We Canadians have a good sense of humor so no offense taken aye! I just hope I was able to provide some clarity, aye.

[Jerry Peck]

In the NEC, NM cable is used at the 60 degree rating even though it has 90 degree insulation.

Yep - I forgot Jeff made mention to NM cable:

... as in the case of 8/3 NMD90.

Presuming, of course, that the NM is for nonmetallic-sheathed cable.

[Mbrooke]

So I have to ask, is NM-90 allowed to use the 75*C column in the CEC?

[Jeff Keyeux]

So I have to ask, is NM-90 allowed to use the 75*C column in the CEC?

"NMD-90" or "non-metallic-dry, 90 degrees celsius uses the 90 degree celcius column in the Canadian Electrical Code (CEC). The listed allowable ampacity is for an ambient temperature of 30 degrees celcius. If the ambient temperature which the cable is installed in is beyond 30 degrees celcius, the ampacity must be de-rated/reduced according to the correction factor listing in the CEC.

- - - Updated - - -

So I have to ask, is NM-90 allowed to use the 75*C column in the CEC?

"NMD-90" or "non-metallic-dry, 90 degrees celsius uses the 90 degree celcius column in the Canadian Electrical Code (CEC). The listed allowable ampacity is for an ambient temperature of 30 degrees celcius. If the ambient temperature which the cable is installed in is beyond 30 degrees celcius, the ampacity must be de-rated/reduced according to the correction factor listing in the CEC.

- - - Updated - - -

So I have to ask, is NM-90 allowed to use the 75*C column in the CEC?

"NMD-90" or "non-metallic-dry, 90 degrees celsius uses the 90 degree celcius column in the Canadian Electrical Code (CEC). The listed allowable ampacity is for an ambient temperature of 30 degrees celcius. If the ambient temperature which the cable is installed in is beyond 30 degrees celcius, the ampacity must be de-rated/reduced according to the correction factor listing in the CEC.

- - - Updated - - -

So I have to ask, is NM-90 allowed to use the 75*C column in the CEC?

"NMD-90" or "non-metallic-dry, 90 degrees celsius uses the 90 degree celcius column in the Canadian Electrical Code (CEC). The listed allowable ampacity is for an ambient temperature of 30 degrees celcius. If the ambient temperature which the cable is installed in is beyond 30 degrees celcius, the ampacity must be de-rated/reduced according to the correction factor listing in the CEC.