On 9/2/21 09:33, Mel Beckman wrote:

Here’s a nice article on the code issue, which is nationwide in the US (it’s part of the NEC). It speaks specifically about the generator requirements:

https://temperaturemaster.com/furnaces-hardwired-what-you-need-to-know/

TLDR: The NEC is against plugged-in furnaces for a good reason: they consume so much electricity that they need a dedicated circuit. When you have a plug-in furnace, you’re likely to plug it into a shared outlet with other appliances. As a result, the circuit gets overloaded, damaging the furnace and the other plugged-in electrical devices or even resulting in a fire. 

So, converting a hardwired furnace into a plugged-in constitutes an NEC code violation.

The article then proceeds to show how to safely violate the NEC with a plug and socket, and how to follow the letter of the law with a transfer switch or interlock kit. 

I think these are the same devices my brother Peter might be talking about. :)

We have two kettles in our kitchen, and one of them seems to be slowly breaking down. So my Mrs. ran both at the same time last week, and was wondering why one of the breakers in our panel kept tripping. The two separate sockets that serve each kettle are wired to the same 20A breaker into the panel. That was an easy one to explain... run one at a time.

Just easier to not encourage folk to breakout high-current devices such as these into regular wall sockets. Most people do not understand the effects of cascading loads on a single circuit, especially when they don't get that different loads generate different current, even if the voltage is the same. And nor should they, if we always implement and certify code compliance.

But alas, the real world...

Mark.