I am considering adding a hot tub to my backyard. Most of the ones I've seen require a 240v 50A breaker, presumably with #6 4-wire.
It would be most convenient to run the line for this from my subpanel in my detached garage. I had an electrician put in the subpanel just a year ago (so it is up to modern standards; previously it was knob-and-tube! house built in 1927) and he set it up as a 60A subpanel. This consists of a 60A breaker at the main panel in the house, run underground to the subpanel in the garage, which has room for eight GE Q-line miniature breakers. Due to the number of available spaces, I'm guessing the breaker panel could handle more than 60A, but it's just limited by the breaker at the main panel and by the amp rating of the wire going between the panels.
There isn't a lot of load in the garage usually, just a couple lights and outlets. I think we could have gotten away with using two 20A circuits, but he wired up two 20A circuits and two 15A circuits, using 4 of the breaker spaces. This adds up to 75A, but from what I understand this is okay since once it hits 60A it would trip the breaker at the main panel and shut off the entire garage. Occasionally we will run a 12A electric lawn mower or other similar electric lawn tools from the outlets. The lights are motion lights on the outside, and switched fluorescent shop lamps on the inside.
Okay, now for the the question: Would it be okay and up to code to run a 50A 2-pole breaker in two of the remaining 4 slots in the panel and hook the hot tub up to it?
I'm assuming that the hot tub isn't going to be drawing close to 50A under normal conditions otherwise it'd regularly trip the breaker. But even if someone is sitting in it with the jets on and say it draws 40A, it seems like I could still run the lawn mower at 12A and have a couple lights on and not trip the 60A breaker at the house. (Related: does anyone know how many amps a typical hot tub would draw at peak and during regular operation?) I assume this line of thinking is why the electrician was able to put 75A worth of breakers on that 60A panel.
But, if any of this screams "could cause a fire" or "not up to code", please let me know! Thanks in advance!