Power draw concerns

[Bucky-Katt]

Hi everyone. Been a long time since I have posted here at MAAST. I am currently in the process of pulling together all the components for a new 215-gallon reef tank to replace my 90-gallon tank.

I’ve done some searches on the forum and did not find anything, maybe I’m searching for the wrong thing, but I have a concern about overdrawing a circuit with all the required equipment (lights, pumps, heaters, etc) that a reef tank requires.

I’ve been wondering if it would be a good idea to call an Electrician to install a couple extra 20-30 amp circuit breakers that would be dedicated to 2 or 3 plugs for the tank only? Good idea? Bad Idea? Necessary? Anyone else do it? I just bought my house about 3 months ago, it’s currently 13 years old, so it should have fairly decent wiring. But during all of my planning, this has been a concern that has been in the back of my mind.

Thank you for any information that you can provide!

Take care everyone.

Brian

[JimD]

Having dedicated circuitry is in my opinion, never a bad idea, necessary? Maybe, maybe not. Total up all your potential amperage, add 10 percent and compare it to the breaker youll be using. That will give you an idea of what youre looking at as far as additional breakers. Its also a very good idea to seek the advice of a professional electrician. Dont cut corners in this area.

[motohead]

Also,keep in mind that the NEC (National Electrical Code) calls for only using 80% of the rating on the breaker.They do that for a reason.It is called keeping your house from catching on fire.

[alton]

Your lighting circuits should be loaded to no more than 50% because of the Non-Linear factor that ballast create(10 amps on the ungrounded circuit could mean 20 amps on the grounded or neutral circuit). Use GFCI breakers in the panel rather than receptacles if possible. And like JimD stated add up what your going to need today and add even more for future. Keep your main pump on a seperate circuit from everything else. You do not want a faulty power head tripping the GFCI and shutting down your tank.

[captexas]

In my opinion, it's best to have circuits added if there is room on your breaker panel for them. I was running a 75g reef with halides, closed loop and everything else and I had to use two different circuits to keep the breakers from tripping. I think it usually occurred when the halide ballasts clicked on. For the 240g I started setting up, I ran two circuits to support it in addition to the one that was existing in that room to make sure I didn't have any issues.

[brewercm]

I agree with adding more circuits if you have the room. When we moved into our house earlier this year I added another 30 amp just before setting the new tank up. It's dedicated to all the pumps ,chiller and heater that are in the garage.

In my old house I had to do the same because I would be fine until I went to vacuum the house.

[Bucky-Katt]

Thanks for the replies, everyone. I had a feeling that it would be a good idea, but I was just curious to see some other opinions. Once I get all my equipment in house, I'll give the electrician a call.

I figure I'll have two 30-amp circuits installed. One for lights, and one for pumps and heaters.

Thanks again, everyone.

Take Care.

Brian

[falcondob]

I had 4 dedicated/20 amp lines put in with GFCIs on each for my 300gal. I have 1800W in metal halide, 440 in actinic, 1/3 hp chiller, 1000W in heaters, two 6100 Tunzes, Dart Return Pump, Calcium Reactor, Kalkwasser Reactor, and misc other items. Glad I did it that way. They have popped 4 times already. Like when the line came off the RO-DI and sprayed a power strip. That was exciting! Personally, I would install as much as you can afford/need. If you need more later, it will cost more than adding now. IMHO.
John

[obtusewit]

Its very easy to size the branch circuit requirements for your tank. Let's build an imaginary tank and see what it is going to take to run it.

First add up all the Ampere ratings, if the equipment is rated in amperes.

Ballast for 2 - F60T12 VHO 2.34 amps each
ARO 175 watt metal halide ballast is 1.65amps

The National Electric Code (NEC) requires that any circuit supplying any type of HID lighting, fluorescent or MH, be derated to 80 % so divide the total amps by .80
Divide the amps shown on the name plate by the derating factor 2.34/.80 = 2.9 VHOs 1.65/.80 = 2.06 MH
use this number in your calculations. Amperes will be on the nameplate as required by NEMA and ANSI.

ok so you have 2 - 175 watt MH and 2 - F60T12 VHO ballasts = 2.9 + 2.9 + 2.06 + 2.06 = 9.92 amps

Next take anything rated in watts. powerheads, heaters etc

Power heads 3 at 35 watts, 1 power head at 15 watts, 1 heater at 200 watts, ozonizer at 80 watts etc etc

Now take all those watts and add them together and divide by 120 i.e. 105 + 15 + 200 + 80 = 400/120 =3.33 amps

next take anything rated in horsepower such as pumps/chillers etc.

1 pump at 1/4 hp and one chiller at 1/4 hp = 1/2 and multiply by 745 = 372.5 watts then divide by voltage 372.5/120 = 3.1 amps. NOTE: If you have something running at 240 volts you should calculate that separately from anything running at 120, just divide by 240 rather than 120.

Motors generally have a pretty crappy power factor if they are not running fully loaded but go ahead and use .80 as the power factor and you will be okay since they are not pulling the full amperage. soooooo 3.1 divded by .80 = 3.88 And remeber that motors and chillers have an inrush current when they start up. Although you don't have to size your circuit breaker and wire to account for this, a chiller that draws 1.5 amps may see as much as a 12X inrush when it cranks up or 18 amps, which can cause a 15 amp breaker to trip. Motors also tend to drive GFCIs a little nutty at times, too, and they will trip. This is caused by the distorted waveform when a motor starts up. Don't buy the cheapy, get a good one! The cheap GFCIs do not have electronics which ignore distorted waveforms, that's why they are cheap! A circuit breaker type is much better than the receptacle type in avoiding nuisance trips.

So now our imaginary tank has 9.92 amps of lighting, another 3.33 amps of powerheads etc, and 3.8 amps of pumps and chillers which is 17.05 amps.

Residential receptacles are usually rated at 15 amps so you would require at least two circuits. And remember that you may very well have other loads plugged into the same circuits since the NEC allows up to 10 receptacles on a 15 amp breaker or 13 on a 20 amps circuit! Everyone knows what a 120 volt 15 amp receptacle looks like, the blades look like (| |), (not showing the ground pin) a 20 amp looks like (-| |).

And BTW Brian, you cannot install 30 amp circuits for 120 volt receptacles ...20 is the max and they must be wired with 12 gauge wire Most houses are wired with 14 gauge which is good for 15 amps unless a local ordinance requires #12 for residential receptacle loads. (Many do now!)

I hope this helps and if I made any arithmetic errors...gimme a break, I am an electrical engineer, we have staff to do the arithmetic...lol