ECN Forum Forums Code Related Discussion Canadian Electrical Code Topics Downsizing wire between baseboard heaters

Good grief ... I never dreamed that Canada would allow wires to be sized using a different set of rules.

Next thing you know, someone will say you can mount your panels sideways!

And upside down darn that rule where the highest breaker handle cant be more than 67 inches from the finished grade.

Electricians are too stuck on whatever they saw the first day at work. The first panel had the main on top so that must be right-side-up. The first plug had the ground up, so that must be right. We're stuck on convention down to the direction of the slot on the cover screw.

I probably wouldn't downsize wires between heaters, but I'll defend my co-workers' (in C eh N eh D eh) right to do it - even if it pisses off a few old-fogey inspectors who didn't do it that way when they had tools.

Code changes that relax rules bug me, too. Not because I'm against change, but it isn't right to criticize someone's work one day and the next day start doing it that way yourself.

Thanks for your responses!

Down sizing in this fashion is electrically safe, as the heaters are fixed loads in a parallel circuit, only drawing what they require... not exactly plumbing

Bond wire was what I was looking for... thanks!!

I worked for someone who had this installation rejected and I couldn't remember why.
And now I also remember why that rejection caused a lot of eye-rolling.

So I need 14/2 and 12/2 nmd cable with a #10 bond wire in them... Awesome thanks!!
I'll just fish it into the cables, if the supplier can't have it made for me.

You re not going to find a #14 or 12 with a #10 bond wire. The bond wires are #14 in those cables.

How did I fail to see this thread was on the "Canadian"forum? Simple- I was grabbing a thread from the 'recent post' sidebar.

Now, pool, I'd like a shot at changing your opinion of plumbers!

In your house, it's common for the plumbing to be laid out like a tree ... a big line at the start, getting smaller as you near the final appliance. This is so the first pipe can supply the shower, the toilet, and the kitchen sink all at once. By the time you get to the final run to any of those things, the line is much smaller- as it needs only to supply that one.

I submit that's exactly what you're doing with your wire sizing. What can go wrong?

Well, there's a big difference with electrical work, in that we have the possibility of dead faults, and circuit breakers.

Break a pipe,and only a certain amount of water will flow. There's no sort of break that will draw more water than the pipe can pass. Not so with electricity.

The wires have to be able to handle hundreds - even thousands- of amps until the breaker trips. That dead short has the same maximum fault current, pretty much regardless of the wire size. Your only hope of saving a smaller wire is to have a smaller breaker on it.

The same matter comes up when someone suggests that we use a smaller wire for the switch leg. After all, it's only a 60 watt bulb - why not use bell wire?

That's why "down South" we don't do as you propose. One might be able to do so,if there is a fuse in the heater (tap rules).

It's probably why Mike reminds you that you still need a full-size ground wire. It's all about the fault current.

Sometimes I feel like I'm the only one who cares what the rules say. 10-814(1) says the bond doesn't need to be larger than the largest ungrounded conductor. After all, if there is a fault, it gets its current from the ungrounded conductor. Why would it have to be larger?

You are perhaps one of the gentlemen in the audience who is not laughing.
If I personally read the post TO YOU...
Apparently the voice in your head isn't as funny sounding as mine...

I jotted down a few more, that I'll save for later.

I'm going to need to test this puppy out in The Lab (the bedroom where the panel is) for my own personal knowledge.
My instincts tell me it'll be just fine.
I'll wire it up and introduce some shorts in the circuit in various places, and get back to you.

If tesla was still alive the book would be thrown at him by his own fans.

If I torch the rug, I'll blame him too.

I can tell you from my own experience that you can trip a 60 amp breaker with short on a #14 wire.

I guess the issue would be an overload to ground that puts the maximum on the wire without tripping the breaker. You could get there if you disconnect the first heaters and re-connect them on the #14 wire and tie them to ground, but you'll need to add a bunch of heaters to make up for the lower voltage across the heater.

The likelihood of this accidentally happening is pretty remote.

Isn't this similar to the rule that allows us to run from a splitter to a fused disconnect?