My friend is taking care of my 25 year old home in British Columbia (Canada) and all breakers were switched off when I went away, except for the Main at the bottom and the garage one for him to be able to activate the garage door to access the garden tools. Now he needs to turn some heaters on in the house to keep the temperature inside above 10C as the weather is cooling down, but most breakers seem to be set up by set of four, with a top-bottom tandem (linked by a metal plate) and a middle tandem (linked by a small bar).

The pic shows the panel configuration after he switched some breakers ON, but I wonder if there are any rules when selectively switching some of these linked breakers ON and OFF? Anything to be careful about? I am concerned with fire hazard as there is nobody in there to detect a problem (short circuit, etc.).


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  • Note that it is the breaker's job to detect short circuits in the wiring/appliance and trip to protect the house wiring. It is exceedingly rare (except for a few brands of breaker box which have been discontinued for several decades) for the breakers/panel itself to cause issues. – FreeMan Nov 27 '20 at 14:01

Turn on breakers for only necessary circuits like heat. Since the house is unoccupied, there's no reason to turn on any of the others.

If you have ever had problems with freezing pipes and have, therefore, installed heat tape on some pipes, ensure that the breakers that control the outlets these are plugged into are turned on, as well. If not, you could end up with pipes freezing and bursting and finding a watery mess when you return.

I do note that in your pic the "Heat" is turned on (red, center pair, bottom right), but also the "Kitchen counter outlets" (blue, center pair, top right) are also turned on. Unless there are vital appliances or other devices (don't leave a space heater plugged in, turned on and unattended!) plugged in, there's probably no reason to have these outlets powered.

  • Thanks, your answer is complete and detailed, Freeman. Good call. I will see if that extra Kitchen counter outlets can be turned off – Pascal Nov 28 '20 at 22:24

These are tandem/cheater breakers. They are double circuit but on the same leg/phase of the panel. When two are next to each other as shown in your picture and with the handle ties, they are protecting a 240 Volt circuit. As such, they have to be operated at the same time. To turn on or off, put your fingers on the two tabs/ handles that are connected and push in the direction to turn on or off. That would be the two in the middle with the round handle ties and the two outside with the rectangular handle ties. The only concern is that the two controlling a 240 Volt circuit are both on or off and the handle ties ensure that.

  • Thanks. So if I understand correctly, there is no concern with having the inner tandem ON while the outer tandem is kept OFF, which is happening right now. – Pascal Nov 28 '20 at 22:18
  • @Pascal That's fine with one on and the other off. They are for different circuits. – JACK Nov 28 '20 at 23:02

These are quadplex breakers and there's nothing weird about them. They're just what some of us call "double-stuff" breakers: getting 2 breakers in the space of 1.

Normally a 240V breaker takes 2 spaces. In fact, a 240V breaker must necessarily take 2 spaces, since it needs to access both poles of power. So, the clever way to "double-stuff" a 2-pole breaker is to have "double tandems" in exactly this way.

Normally, on quadplex breakers, the inner 2 breakers are tied, and the outer 2 breakers are totally independent. That makes a lot more sense, eh?

However, there was market demand for a "quadplex" that would support dual 2-pole. On its face, that was a simple modification -- develop the wacky-looking "outer handle-tie" to tie the 2 outer breakers. That's good enough for 240V-only appliances and 120V-only multi-wire branch circuits, since the handle-tie is only there to be a maintenance disconnect.

Here's an interesting fact: UL requires that breakers "Trip Free" -- that is, they must trip even if you are holding the handle in the "on" position. Result: Handle-ties are useless for assuring common trip! So you think "Gosh, how can that flimsy outer handle-tie telegraph trip to the other breaker", it doesn't have to. Common trip is an internal mechanism within the breaker.

Common trip positively assures that if one leg overloads, both legs trip. It is only required on 120/240V circuits (240V appliances with neutral, and multi-wire branch circuits that serve 240V loads too).

Not all quadplexes provide common trip. Some only on the inner, some none, some both.

  • 240V breaker must necessarily take 2 spaces - could you please expand on that? Is this specific to the US? In Europe the 230V breakers take one space (see for instance m-habitat.fr/electricite/tableau-electrique/… - a typical breaker panel in France) – WoJ Nov 28 '20 at 18:27
  • 1
    Yes, it's strictly US (more precisely, strictly 120V). We have completely different setups in Europe. In the US, when they want to use 240 V equipment, they have to do it by connecting it between two opposing 120V "legs" (homes receive two legs and a neutral in the middle). These cases are manufactured so that every other position comes from the opposite leg: odd, even, odd, even, etc. Hence the need to span two positions for anything that's 240 V. – Gábor Nov 28 '20 at 20:16
  • Thanks Harper! Well, this is going to require some coffee and a new 1 mA brain breaker, but I will come back on it after I graduate. – Pascal Nov 28 '20 at 22:21
  • @WoJ Yes, StackExchange is a Q&A site. It is axiomatic to Q&A sites that answers only exist in the context of questions (nothing is a blanket statement). OP's panel is distinctly North American/Philippines. Our 240V is analogous to your 400V (i.e. your power is 3-phase up at the pole, some houses get 2 or all 3 phases; phase-phase voltage is 400 and you can put big loads on that.) – Harper - Reinstate Monica Nov 29 '20 at 3:30
  • @Pascal Yes, and when you graduate, your next google phrase is "Multi-wire branch circuit". Your house has a lot of them. Nothing wrong with them, but they must be handled correctly. – Harper - Reinstate Monica Nov 29 '20 at 3:32

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