Are Breaker Interlocks Legal?

Although generator interlock kits are cheap, there are often regulations involved with them. Despite this, they are legal in the United States as long as they are installed up to code. Some jurisdictions require you to have a professional do the work, o make sure you're able to do it on your own before you begin.

Which is better transfer switch or interlock?

Compared to a transfer switch, which is limited to a particular number of circuits, an interlock kit allows you to run power from a generator to any circuit within the electrical panel. While this is good in theory, there's a risk of overloading the generator if it's not sized according to the load.

Are interlock kits legal in Canada?

They are still legal and meet code in Canada. We've never bogged down the generator, err on side of caution with load.