Clothes Dryer Circuits in Ontario

[John Allingham]

I just wanted to pass on some info I recently received in case there are some Ontario inspectors who may not already be aware of it.
Three of the last five homes I inspected, all 70's and 80's vintage, had dryer circuits comprised of 40A breakers and #10 copper wire. I called for further evaluation because a 40A breaker requires #8 wire, but I also thought this was too much of a coincidence so I contacted the ESA.
They advised that, over some period in the 70's and 80's, it was acceptable to the ESA to have a 40A breaker on #10 wire for this application. The reason - some very powerful dryers were being produced over that period causing nuisance tripping of 30A breakers.
Dryers now must consume 24A or less and therefore only 30A breakers are allowed for the #10 wire used today.
It still leaves me a little confused about what I should be writing when next I find a 40A breaker on #10 wire in an older house.

[cboyd]

Since those dryers with nuisance tripping would be long gone now we could just note that it is recommended a 30 amp breaker be installed at some point when we see #10 wire. A short explanation, verbal and in the report as to why we comment on it this way. Good point to bring up.

[dcook1]

Originally Posted by cboyd

Since those dryers with nuisance tripping would be long gone now we could just note that it is recommended a 30 amp breaker be installed at some point when we see #10 wire. A short explanation, verbal and in the report as to why we comment on it this way. Good point to bring up.

Charles got it on the first try.... definitely explain to the client they should change it for safety. Remember, if they don't (and probably won't) at least you have told them.

[William R. DeVries, CMHI]

Originally Posted by jallingham

I just wanted to pass on some info I recently received in case there are some Ontario inspectors who may not already be aware of it.
Three of the last five homes I inspected, all 70's and 80's vintage, had dryer circuits comprised of 40A breakers and #10 copper wire. I called for further evaluation because a 40A breaker requires #8 wire, but I also thought this was too much of a coincidence so I contacted the ESA.
They advised that, over some period in the 70's and 80's, it was acceptable to the ESA to have a 40A breaker on #10 wire for this application. The reason - some very powerful dryers were being produced over that period causing nuisance tripping of 30A breakers.
Dryers now must consume 24A or less and therefore only 30A breakers are allowed for the #10 wire used today.
It still leaves me a little confused about what I should be writing when next I find a 40A breaker on #10 wire in an older house.

As this is not a code specific inspection, during the 1970 -1980's the Electric safety Standards allowed the Branch circuit have 40amp on a #10 gauge wire. It's reason as per ESA was the dryers then were less efficient and had a much heaver consumption. Todays dryers are " Energy Star" Compliant and inasmuch use less electricity. If your current dryer is an "energy Star " Compliant model it is recommended to have this circuit changed to todays electrical codes. Recommend electrician repair or replace as needed. This is for your information