When I moved into my house I noticed an electrical box with two switches on it that connected to thermal safety switch for my hot water heater and heater for the house (forced hot water). I have posted a picture below. My question is what exactly is this? Is this a type of manual transfer switch that I can attach a portable generator to? Thanks in advance for your responses.

electrical box

  • Gypsy generator transfer switch using two CDN$2 3-way switches (aka SPDT), problem is they must be thrown together to be safe (also not rated for the current. Would be safe if he used a double/2-pole 3-way or DPDT switch, such as this one, – Harper - Reinstate Monica Jan 3 '18 at 18:08
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    Actually I don't see a third cable coming out of this, so this may just be a disconnect, where he figures he's gonna shut off the main breaker before turning on these switches. – Harper - Reinstate Monica Jan 3 '18 at 18:25
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    I don't think anyone can give you a definitive answer from the information we can gather from your text and picture. Either yourself or someone else needs to trace out the wiring and identify what it really does. Right now I am torn between it being a really bad attempt to make these two switches a transfer switch or the installer had a small generator and these switches were to choose which major load he wanted to run. – Retired Master Electrician Jan 3 '18 at 20:34
  • Can you get us photos of the actual wiring in the box, or a diagram for that matter? – ThreePhaseEel Jan 3 '18 at 23:20
  • Also, is that cordage I spy extending outside of the box? – ThreePhaseEel Jan 3 '18 at 23:21

Disclaimer: my answer is based of off the Ontario Electrical Safety Code (26th Edition/ 2015) Current Edition. I would advise calling a licensed electrical contractor in your area and have them see if this complies with your local rules and regulations.

It does appear to be a very crude and illegal generator transfer switch. I would look on the outside of your house or the shed (if applicable) for a empty area with a dead end box (if it was hardwired) or a generator inlet box (if it was a plugin style) this will be where the generator was previously.

I would also suggest that you take a good look at anything else that looks like it was added by the previous owner as this is not the proper method of isolation for a transfer switch and was likely done without a permit which means the it and other homeowners additions may not be safe. Call a electrical contractor and ask them to inspect this and see if it is safe.

typical generator inlet box

a proper manual transfer switch

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