Some questions for the Canadian guys

[Eddy_Current]

But, handle tie breakers should still be used rather than just sharing the neutral, if only for a safety consideration.. I mean, let’s say you are sharing a three phase circuit as three single phase live, one neutral, one ground, each phase on its own as far as outlets are concerned as all equipment is on 120 volts... even if you run a larger neutral and a larger ground than the live wires, there is still the potential of overload through heating of the neutral or of a fault that trips the one phase still allowing current on the neutral thus still faulting on the other phases but not tripping...

so, how do you account for it? With a sign that says if breaker x is tripped y and z need turned off to work on circuit?

Would rather a handle tie at least... and I am one of those they call a handyman who is studying code.. I think I am qualified to do a lot of electrical but this forum has taught me that I have a lot of learning to do...

I agree for safety they should be tied, but they don’t have to be and rarely is done. No labeling required. We are used to it and know to look for it.
For instance, in most commercial buildings they will have three circuits for lighting, all sharing a neutral on three single pole breakers. At 347 volts you can put many lights on one 15 amp circuit so when you turn off one of them, it could turn off all the lights on half of the floor. Then if you get into the junction box assuming power is off but there still is potential danger working on the neutral supplying the other two circuits.

 

[electrofelon]

But, handle tie breakers should still be used rather than just sharing the neutral, if only for a safety consideration.. I mean, let’s say you are sharing a three phase circuit as three single phase live, one neutral, one ground, each phase on its own as far as outlets are concerned as all equipment is on 120 volts... even if you run a larger neutral and a larger ground than the live wires, there is still the potential of overload through heating of the neutral or of a fault that trips the one phase still allowing current on the neutral thus still faulting on the other phases but not tripping...

so, how do you account for it? With a sign that says if breaker x is tripped y and z need turned off to work on circuit?

Would rather a handle tie at least... and I am one of those they call a handyman who is studying code.. I think I am qualified to do a lot of electrical but this forum has taught me that I have a lot of learning to do...

I disagree. I find handle ties increase the shock Hazzard significantky on mwbc's in the real world. that was a horrible code change.

 

[GoldDigger]

I disagree. I find handle ties increase the shock Hazzard significantky on mwbc's in the real world. that was a horrible code change.

I can see how handle ties make it more difficult to handle [sic] a problem on just one line circuit. But other than making you more reluctant to turn both or all three sides of the circuit off to work on one and thus being motivated to work hot, I do not see a safety problem.
Can you elaborate on that?

 

[electrofelon]

I can see how handle ties make it more difficult to handle [sic] a problem on just one line circuit. But other than making you more reluctant to turn both or all three sides of the circuit off to work on one and thus being motivated to work hot, I do not see a safety problem.
Can you elaborate on that?

Yeah pretty much its the working hot thing, due to uncertainty what the other two circuits are and/or them being in use. For me personally I have worked many times hot due to this, and Im sure there are plenty of other idiots like me out there

 

[Eddy_Current]

I disagree. I find handle ties increase the shock Hazzard significantky on mwbc's in the real world. that was a horrible code change.

I agree that the NEC rule on this was not necessary, but to say that handle ties increase the shock hazard significantly is an incorrect statement. It’s not the handle tie that is the hazard. It is you being worried about not disconnecting other circuits and choosing to work live. Turning off someone’s computer is not a hazard.

 

[414Mhz]

Figured I'd start off the new forum section with a few questions for our neighbors to the north:

1) for those familiar with the Canadian electrical code and the NEC, how similar are they, what major differences have you noted?

Thoughts and comments?

Differences I can think of:
Outside receptacle is dedicated outlet here, not for you.

SABC, seems you can feed other loads from this. (ie, fridge). Our counter receptacles are dedicated.

Bathroom circuit, for us it's just part of the 12 receptacles on the circuit. From what I understand NEC allows recepts for more than one bathroom, but then you can't use it for lighting ??

We can load up resistive heating to maximum rating of conductors, and upsize OCPD to meet 80%

We can use the 75˚ column for cables (for the most part). Seems NEC only allows this with conductors, not cables ??

All I can think of for now.

 

[electrofelon]

I agree that the NEC rule on this was not necessary, but to say that handle ties increase the shock hazard significantly is an incorrect statement. It’s not the handle tie that is the hazard. It is you being worried about not disconnecting other circuits and choosing to work live. Turning off someone’s computer is not a hazard.

Well if the NEC is going to try and brother-in-law proof things, then they should think about other real world stuff then too

Differences I can think of:
Outside receptacle is dedicated outlet here, not for you.

SABC, seems you can feed other loads from this. (ie, fridge). Our counter receptacles are dedicated. fridge and dining room

Bathroom circuit, for us it's just part of the 12 receptacles on the circuit. From what I understand NEC allows recepts for more than one bathroom, but then you can't use it for lighting ?? yes. It can do lights in the bathroom if its just that bathroom, or plugs in multiple bathrooms, but then no lights

We can load up resistive heating to maximum rating of conductors, and upsize OCPD to meet 80% The "80%" rule in the NEC is (in general) for conductors and OCPD's

We can use the 75˚ column for cables (for the most part). Seems NEC only allows this with conductors, not cables ?? NM and UF are restricted to 60 degree, other cable types are 75. SE cable was on the merry go round for a few code cycles, now its back to 75.

All I can think of for now. Teck cable! I want

 

[Eddy_Current]

Here’s another one. We can not put wires from different sources in the same raceway unless they are for the same piece of equipment.

 

[Reltek]

In Canada the main breaker is isolated from the rest of the panel so entering the panel with branch circuits or feeders is not possible from the top of the panel. Hence the sideways setup.

Yes the service switch (main breaker) compartment is for the service conductors only, but the panel can be mounted either sideways or vertical. Most of the panels I've seen in BC are vertical and I always try to mount mine vertical unless there just isn't room.

 

[ccst]

Figured I'd start off the new forum section with a few questions for our neighbors to the north:
2) do you guys have 480 / 277 like us, or is it all 600 / 347v? I have read that both have similar arc flash potentials, the higher voltage seems desirable as, all other things being equal, one would have 25% more current capacity for the same size wiring. Thoughts and comments?

I am in Western Canada and have yet to see a 480 system here. I know BC Hydro will not support it for the service entrance unless you supply all of the transformer equipment. The norm for most new commercial warehouse type buildings going up is to have the lighting on 347 and a smaller 25 or 50 kVA step down transformer near the main panel to supply the utility outlets.

There are several NEMA options available for L-N and L-L connections. They have a 347 straight blade receptacle for light duty applications like air dampers or lighting (NEMA 24-15), though the twist locks (NEMA L17-30 for example) are more commonplace for plug in equipment.

 

[funksparky]

Yes the service switch (main breaker) compartment is for the service conductors only, but the panel can be mounted either sideways or vertical. Most of the panels I've seen in BC are vertical and I always try to mount mine vertical unless there just isn't room.

I just wanted to reiterate that, at least from what I’ve seen, most resi panels are not mounted sideways here. But we can. I personally try to avoid it- I hate it. It can be helpful in some situations and like [MENTION=69382]eddycurrent[/MENTION] said in service upgrades with short existing wires. I worked for a guy for awhile who liked to install his panels sideways, but I didn’t inherit that method. Interesting thread!


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