Ohm's law, simple electrical equations

Hi,

Heres a few simple equations for new growers who aren’t familiar with electricity and indoor growing equipment.

These equations will help you convert different electrical values to help you figure out what you need.

I = amperage
V = voltage
P = watts

Watts ------> Amps

1000 watts = ? many amps

I = P ÷ V

I = 1000 watts ÷ 120 volts

I = 8.3

1000 watts = 8.3 amps on a 120 volt circuit
1000 watts = 4.1 amps on a 240 volt circuit
1000 watts = 2.8 amps on a 347 volt circuit

Thats the one you’ll use the most, its usefull for calculating breaker size, wire gauge etc.

Here’s two more equations that you might need and doesn’t hurt to know them when your doing electrical work.

V = P ÷ I
P = V × I

Thats it, very simple and quite usefull, I have to specify that your calculated values will vary slightly from actual mesured values using amp clamps and multimeters but they will give you a very good indication of what you will need to put together your project without necesarily needing to hire an electrician. Downloadable versions of both the NEC and CED are available and all electrical work should be done according to local code for safety rasons.

I’m from Quebec so some of our electrical codes might be slightly different but from what I have been told the canadian code is heavily based on the national electrical code (usa) so other then the 50/60 hz frequency difference this info works for all of north america.

If you have big grow rooms I always recommend owning the basic electrical tools of the trade ex a good multimeter and amp meter…Never load a wire or breaker more than 80% it’s capacity.

You can always pm me for info if needed, I’ll try to help out as much as I can.

I’m apprentice electrician and I’ve done residential, commercial, automation, electronics(not my specialty), low voltage controls, intrusion alarm systems and fire alarm systems.

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I learned in french in Quebec by the way so some of the ohms law value abreviations ex I, V, P might be different in english, I’ve never checked… but basically the equations remain the same and will give you the same values…