How much more can I get out of my homes 100A electric service? Is there a rule of thumb for calculating estimating it? I am thinking about a hot tub but want to figure out if I'd have to upgrade the service or just add a new 50A breaker and wiring. All I could find online was boomers saying their electrician told them it would fine. How would an electrician actually go about estimating that?
I tallied all the major appliances in my house:
>>> oven = 3400/240
>>> dryer = 15+4500/240 # 30A breaker
>>> disposal = 8.1
>>> dishwasher = 8.7
>>> ac = 45*.8 # estimate: 30A + 15A breaker
>>> tub = 50
>>> oven+dryer+disposal+dishwasher+ac
100.71666666666667
>>> oven+dryer+disposal+dishwasher+ac+tub
150.71666666666667
>>> disposal+dishwasher+ac
52.8
>>> disposal+dishwasher+ac+tub
102.8
>How would an electrician actually go about estimating that?
By looking at your neighborhood, your cars, and asking what you do for a living.
I meant estimating the electrical load, not the cost. I drive a beater so people think I'm poor.
I am in the US. Doesn't that mean technically I'm already over? That doesn't even include my computer or lights. But yeah of course not everything is used at the same time nor is everything pulling 100% all the time.
>>> oven+dryer+disposal+dishwasher+ac
100.71666666666667
Can I add 50A to this an just be careful? If i diy no code nazi has to know about it
>Is there a rule of thumb for calculating estimating it?
Yes. In your case, it's 100A. Unless you're in the US, in which case it's actually 80A.
Either way, unless you're running all that shit at the same time, it's not a problem.
our service panel is 200a in AZ.
Get the cheapest amp meter at Harbor Freight and measure each leg when appliances are on that will be on when the tub heater is running.
240v or 110v?
This stuff isn't running all at the same time. Depending on the nature of the appliance, a multiplier of 75% or so is added to account for this when calculating maximum load. However, the maximum load is only allowed to occupy 80% of the service rating (80A)
TL;DR 50A hot tub probably isn't possible without upgrading your service. You should upgrade to 200A anyways because it will improve resale if the next owner wants to install an EV charger or something
nobody uses ALL their appliances at the same time.
where do you live?
pretty girls make me sad
Your panel probably can't handle an additional 50a load. Quit being cheap and put a 200A panel in, you'll need the extra space in the future anyway.
Frick it anon, keep adding breakers till it catches fire.
It doesn't matter what appliances or devices you actually use, all that matters is the sum of all the circuits in the panel. The only time actual device usage is taken into consideration is when sizing individual circuits, however for panel capacity it must be assumed that at some point in time every circuit may be in use at its full capacity simultaneously. So add up the amps of all the breakers and subtract that from the amps of the main breaker and that's what you have left to work with.
It's the same way that the size of an incoming water supply line is calculated. Total number of fixtures x gph that each of those fixtures use = required gph of incoming water supply. Of course this will work out to a worst case scenario where every single fixture in the house is being used at once which in reality is likely to never happen, but when sizing the supply it must be assumed as a possibility.
I would guarantee your service is good for 200 amps if you're in the US. We don't provide any 120/240 single phase service less than 200 amps anymore. 100 amp services are a single 120 leg nowadays. Check your meter, if it says CL200 on the faceplate it's a 200 amp service.