Electrical Help

I just ran a designated 20amp line to my room. I'm either going to get a 600w HID or up to 600W of CFL's.. Not looking for opinions on HID vs CFL's Just wondering which ever one I choose, is 600w of HID and 600w of CFL's going to draw the same amount of amps? Any idea of what that draw would be? I'm wondering if I'll have room for a few more things like a couple fans maybe a few more CFL's or something on the same circuit?

600 watts is 600 watts no matter how u look at it. Is your 20 amp line gonna be 120 volt or 240 volt? You can use Ohm's law for the value needed. Watts= volts x amps. So on a 20 amp circuit that you ran it would be 120 volts x 20 amps = 2400 watts, code says that you can only load a breaker to 80% , but thats code and not reality.

Well ill tell ya one thing 20 amps is an awefull lot you could run nearly as much as you like off a 20 amp MCB Please be carefull because 20 amps is more than enough to kill you so dont go messing around with live wires

lol yeah I wasn't going to chew on the wires or anything... It's a 120v, 10 guage wire... I suppose I could just go 10 or 15 amps.. What would you do? If I ever do go caregiver mode, it might be nice to be able to run 2 1000K's.....

Correction, I have 12g wire.

12 g wire is good for 25 amps. if u want 2k of lighting then keep it at 20 amp circuit , just make sure your outlets are rated for 20 amps.

All good advice and I agree but just to add some info that might help someone else, my comment would be that"a lot" of power out of 20 amp circuit is a reletaive term.
In a residential you are allowed to install thirteen plugs on a circuit which is "a lot" but I think that is assumed that not every plug is going to be maxed out at the same time.
If you are on a breaker and it is overloaded it will simply blow the breaker and then you will know. No danger as long as it works which it will for sure.
As far as wire size, there are a couple of decisions that you can make that can effect you on a positive or negative basis. Not quite as cut and dried as the breaker decision.

If the wire size is too small for the run, and the amount of power the appliance drws then you will experience a power drop and heat due to resistance.
A bigger size wire moves more power a longer distance without exhibiting these issues.
Code says you can use 14 gauge wire but if you are getting close to max you will actually save money by reducing the power loss and associated heat that is caused by resistance or lack of efficiency with the smaller wire size.
That's where 240 V comes in handy. It still draws whatever amps required by the appliance but by splitting the power requirement into two 120 circuits which is what 240 is
you can reduce the size requirement of the wires needed to feed the juice and it will do it more efficiently than moving that amount of juice on a single 120 V circuit.

Bottom line, since we are probably maxing out a cicuit it pays to run big wire. That will assure you of bright lights, strong fans and low heat due to resistance.
Did I get that about right?

and if you are 80ft from panel you need to upsize your wire due to voltage drop , u are correct doser on the 240 circuit but he would have to run a 3 wire , 2 hots and a neutral. If not you could not get 2 120 volt circuits because there would be no neutral and it would be better to make it 2 120 volt circuits because each 120v cct would be on a breaker. You can pre wire your ballasts for 240 if u open them up & rewire, that would allow u to put more lights on a breaker.

and 14 g wire is only good for a 15 amp circuit , he ran a dedicated 20 amp cct with 12 g wire , he is all good.

jgould said:

and if you are 80ft from panel you need to upsize your wire due to voltage drop , u are correct doser on the 240 circuit but he would have to run a 3 wire , 2 hots and a neutral. If not you could not get 2 120 volt circuits because there would be no neutral and it would be better to make it 2 120 volt circuits because each 120v cct would be on a breaker. You can pre wire your ballasts for 240 if u open them up & rewire, that would allow u to put more lights on a breaker.

Click to expand...

no arguement here bra

so was it redundant for mt to use ground hot and neutral wires with 12 gauge on 20 amp breakers and plugs, wire ran 25 foot away from the panel to 20 amp duplex outlets?

i ran 2 of the above mentioned circuits, and i only use 1 1000w hps a 850 watt A/C unit a couple fans and a bubble machine, so i dont think i have anything to worry about. everything has been working so far.

soundsto me like you did it right. A lot of times electricians run an extra circuit for "future" needs.
You may be fine now but if you add a floro for a mther or some new vegg lights or that disco ball that you have been mulling over, the "extra" ciruit may come in handy

i dont mean to jack the thread. but while people with knowledge about electricity are here i figure id get this off of my back...

i didnt really run an "extra" circuit per se. buy i hooked both of them up. i probably wouldnt have to use them both to power everything i have to use. but i do just as a safety precaution.

is there anything wrong with what i did? or is there anything wrong with using the both circuits instead of one (less power consumption?).

me not being an electrician i had to ask the home depot dummys for help... at least they knew more than i did LOL!

take a look at my mock sketch, from what you see here is there anything that doesnt look right from a safety standpoint?

Edit: i wired my outlets up 120V if it makes a difference...

It never hurts to under utilize a circuit
there is no down side to that
you're golden

I believe that 600W is the output rating of the bulb. Because of inefficiencies the ballast draws more than that. It's not huge around 15% I think. CFLs are better that way.

The longer the run, the heavier the gauge you need. For short runs, 10ga will carry a lot more current than you can use without significant voltage drop or heating.

I have 10ga running about 12ft from the big #2 power lines under the house and I feed that into a small breaker box in the grow room with two 15a breakers. Its a good idea to have a breaker box in your grow room, they aren't expensive.

Let's say 800W for the lamp, that's about 7A of steady draw but when the lamp is first turned on there is a short current surge that can go much higher (digitals are better in this regard because they don't have the heavy inductive load of the transformer). This means you should have plenty of spare capacity in your circuit. I dont like to go over 2/3rds

If you run an a small AC unit like me thats another 500w-1000w so say another 8A.

Fans, probably around 25W each. Say four fans that's 1A

10 25w CFL lamps another 2-3 amps.

That's about 18A total. I used high end estimates for the wattages and for the number of lamps & fans so this is conservative.

Conclusion: If you dont have an AC unit then you are fine with a 20A breaker using less than 12A steady draw. If you add the AC you want a 30A service like mine. If you also add another 600W lamp, Then you need a 50A service and might have to run 6ga wires. Dunno, would have to look it up.

Couple of other things:

Outlets on a 20A breaker do not need to be 20A. You can use regular 15A sockets as long as the draw through that socket stays under this limit.

240V is superior in several ways, one being you can use much smaller wires. Don't mess with it unless you really know what you are doing. You may be able to run the ballast on 240V but the rest of the stuff will be 120v so you dont gain much. The wiring is a bit more complicated (not much but it may be unfamiliar). You need special outlets and plugs. It's a lot more dangerous than 120v and much more likely to kill you if you get shocked (it will deliver 4x the power to your body). This is a serious concern in a cramped environment where water is being used.

Keep it neat. Keep it tidy. Do it by the book and don't take shortcuts. Buy a cheap outlet tester to make sure your outlets are wired correctly - that you haven't switched ho hot and neutral and that your ground is good.

Don't use extension cords!!. They are a very serious hazard especially around water. I have professional experience with exactly this kind of accident. Put up lots of outlets. If you find you need an extension cord in your grow room for more than a short while, wire up another outlet. Try to put the outlets well above the height of your pots.

Spend some time managing your wiring so it doesn't become a tangle. Wind up any surplus on power cords and tape the loop. Put small hooks or keepers on the walls to hold power cords against the wall. You should be able to move the plants and the lamp easily without risk of snagging a power cord.

Periodicaly, when everything is running put your hand on the outlets and power cords. Anything hotter than slightly warm to touch is a danger sign. Either the draw is too high or there is a bad connection somewhere that's getting hot. Power cords on cheap Chinese electrical equipment are a bit undersized and tend to get slightly warm.

First of all just because you run something 240 doesn't mean u can run smaller wires? Its all in breaker size and amperage which determines wire size and yes regular 15 amp outlets work , its just not code , either is your 18 amps on a 20 amp circuit if u wanna get technical.

Put an ammeter on a wire in your panel that powers your 600 watt ballast , it will not be 7 amps steady , maybe on startup .

not to argue with you but as an avid woodworker who has investgated the pros and cons of 220 motors vs 110 motors adnausium on the internet and talking to some very good electricians I say you're wrong about the smaller wire.
Let's say you're using an appliance, let's stick with a motor say on a tablesaw. Let's say it draws 20 amps at startup and 10 at full speed
if you pull all those amps through a single line of 110 then you have to size your wire accordingly. if you take that same draw and divide it equally between two hot legs of 220V then you have reduced your requirements for the wire by 1/2. So now each leg pulls 10 amps at startup and 5 amps once it achieves full speed.
that ain't theory my friend it is fact. I own a meter and use it all the time. this I would stake your life on.
a lot of people see a fat cord and automaticly think 220 V but that just ain't how it is
a lot of prople think you save money by using 220 V............ain't so

220 doesn't divide the load evenly, each leg has same amount . If a motor draws 20 amps then each leg has 20 amps on it , no way does it get divided on each leg with 220 . Sorry doser i do not agree and i will bet your life on it. lol

jgould said:

220 doesn't divide the load evenly, each leg has same amount . If a motor draws 20 amps then each leg has 20 amps on it , no way does it get divided on each leg with 220 . Sorry doser i do not agree and i will bet your life on it. lol

Click to expand...

Right. The current flows from the one hot to the other. The neutral line, which is at 110v from either hot, is not used except sometimes as a ground.

Ohms Law V = AxR where V = voltage, A = current, R = resistance
also W = AV where W = watts

From ohms law, A = R/V so that

W = VxV/R or V^2/r ( In English, watts equals the square of the voltage divided by the resistance.)

This means that for a given length of cable with a resistance of R, doubling the voltage will drive 4x as much power through the same cable!

There are many common examples that demonstrate this:

Car battery cables. It can take 5kW to turn the engine over to start. Since the battery delivers 12v, the cables are 4ga. The same load on a 110v appliance, a small AC for example, runs on 12 ga wires from the outlet.

Power transmission lines: Power lines are run at very high voltage which is then stepped down through a transformer just before reaches the service at the house. These voltages are extremely dangerous. Utility company workers get killed. The lines have to be high above the ground with special insulators where they are supported by the pylon and you need big, heavy duty stepdown transformers. All very expensive but worth it because it allows using much smaller conductors over long distances.

I have an arc welder. It puts out up to 300A at 24v. The welding cables are 1/0 (thicker than 1ga !) The power cord to the welder supplies 220v through 6ga cables.

Look at any stepdown transformer. The high voltage windings are always a smaller gauge than on the low voltage side.

Domestic house wiring runs at 110V in the US. This can be, and too often is lethal. Why not use 24v for domestic circuits? Again because of the expense of the wiring.