Growroom Electricity Question

Hello RIU! FInally getting growing in the fantastic, weed-legal state of Colorado! I am super excited to be here and really can not wait to hit the ground running.

I will be starting small (you'll see that my definition of small might be a little different than yours, but moving on...) due to plant count limitations and such.
During the last two days, I've had an electrician out here to bring me the necessary power into my little grow area. Well, trenches were dug and wiring was pulled. However it seems service where I live is only 100 Amps. My growroom is getting 60 Amps. Will this be enough for me to run my system?

I'm running:

(1) 36,000 BTU Mini-Split
(13) 650w ballasts
(3) 8" fans

That's about 3000 watts, plus about 8500, plus about 600, and plus about 250 for all my hydro pumps. We'll say 12,500 watts total with all the odds and ends.

Ohms law states that Amps = Watts / Volts. Well if everything was ran off of a 120v circuit that would be 104 Amps. Way over. However, the Mini-Split and ballasts all have 240v plugs. Using Ohms law that would be, 48 Amps for the 240v stuff and another 8 Amps for the other stuff on 120v. That's 56 Amps... still sketchy, but should work, right?

This is where I'm confused. The way that the electricians were explaining things to me is that amperage is NOT cut in half like that. It goes against everything I've read. I even called another electrician and he said that, yes, more volts is equal to less amps. So why would these two men tell me that it doesn't work that way? The logic is, 240v breakers are nothing but two 120v breakers put together and therefor the amperage doesn't change. For example with my 650 watt ballasts, it would break down into 325 watts go through one 120v breaker and 325 watts go through the other. Basically saying that 325 watts / 120 volts TIMES 2! Which for all you math aficionados out there is 650/120. So what is it? Is it 650 watts divided by 120 or 240?

The difference is I want to have my grow room be able to run at full potential in the occasion that I am able to find 5 patients and have an 18/18 plant count. It's literally the difference between being able to run maybe 5, 6 lights and running them all. It would work at first because I only have a few plants growing, but eventually I would have to get more work done.

Bonus questions: How should I wire my grow room for all these 240v outlets? Should I invest in a PowerBox?

Main breaker

Trenches dug
Grow room panel

Your logic that 240v breakers are nothing but two 120v breakers put together is incorrectly worded. It would be more logical to think that double pole circuit breakers are nothing but two single pole circuit breakers put together. In this scenario each of the single pole circuit breakers are on separate poles (different "hot" legs of the bus bars). A 240 volts circuit does not connect to neutral, and thus is utilizing voltage from the entire length of the secondary winding in the power transformer. A 120 volts circuit does get connected to neutral (the center-tap on the secondary winding), and thus is utilizing voltage from half the secondary winding in the power transformer. However, not every 120 volts branch circuit is receiving its power from the same half of the secondary winding in the power transformer. Although every 120 volts branch circuit is sharing the same neutral bus bar, if you examine the configuration of the "hot" bus bars inside your breaker panel you should notice that each consecutive breaker space in that column is alternating from a different leg and thus will have alternating halves of the secondary winding of the power transformer.

I'm sorry, But what does that mean about my overall amperage? My house is 100, minus 60 that is going to the grow room. Meaning I've got 40 amps for a/c and appliances and if I go above that, assuming the growroom is running at full capacity. i think it could be next summer who knows.

Ive spoken to a craigslist mmj electrician and his opinion is yeah, 60 amps is going to be fine in the garage, but I'll be tripping the main breaker all the time, therefor i need a service upgrade to my house.

BTW I was ripped off by the electric company that installed the subpanal. they did it for a price that made the other electrician laugh. poor me, white, young, and seemingly full of money so those bastards did a quarter of what i could have paid for.

Your numbers are way off. Your not going to be able to do 8k watts and a 3 ton on 60
Amps. First off unless your bringing fresh air, a 3
Ton won't even cool 8k watts.. Next your not calculating for dehumidifiers . Wall fans , floor fans , scrubber fans , pumps . I have a 9k watt room that pulls just under 100 Amps fully loaded . I hope this helps you . I sure as hell hope you didn't run 4 gauge wire too because me and my buddy already made that mistake . You need a 200 amp service upgrade

Also you can only load a 60A breaker to 80% so your dream of running 56A,continously isn't going to work either. Pay for the 200a service and Run a 100A service out to your garage. That will give you plenty. If the 60 is already installed and the trench is still open run another cable in there now so you don't have to dig it all up again if you want to upgrade on the future

get growing, the trench is still there so thats likely what I'll be doing.

patrick, i may choke on my words later, but the a/c should work just fine here where I live. it needs to be around 80 with CO2. i also did calculate for all those things that you stated in my first post. Its my belief that you want an air tight room with a/c so the cool air is not replaced by warm air.

im getting the estimate soon and the work done this weekend. the first electrician screwed me and all the money i saved by contacting the hydro store reps went right into that. We'll see about my a/c. it says right on the box it cools 1450 sq. ft or 8000 watts. I've got 8000 in 400 sq. ft.

ryan s said:

get growing, the trench is still there so thats likely what I'll be doing.

patrick, i may choke on my words later, but the a/c should work just fine here where I live. it needs to be around 80 with CO2. i also did calculate for all those things that you stated in my first post. Its my belief that you want an air tight room with a/c so the cool air is not replaced by warm air.

im getting the estimate soon and the work done this weekend. the first electrician screwed me and all the money i saved by contacting the hydro store reps went right into that. We'll see about my a/c. it says right on the box it cools 1450 sq. ft or 8000 watts. I've got 8000 in 400 sq. ft.

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the electrical isn't going to hold. I have rooms and have friends wirh rooms very similar. My buddy just set up 8 gavitas on 4 gauge . He is now digging a new trench for a second subpannel cause he is a dumbass and didn't listen. If you want to do the same shit I'll gladly say I told you so one more time . The Ac will do 8k watts if you are air cooling the fuck out of your lights. If you are sealed and not using glass , you aren't going to be able to pull it. I can barely do 9 lights with 4 tons .

My buddy's 8 lighter is running 110 amps.

My 9 lighter is at about 95 amps

60 amps is about a 4 lighter being safe