Grow Room Design & Setup
Experienced Electrician! Here to Answer Any and All Growroom Electrical Questions in the
The Grow Room forums; Originally Posted by its a hobby honey !
i have a quick question! i have been building a ...
07-27-2013, 12:58 PM
Hot Tubs and Spas most commonly have a 5500 watts 240 volts water heater, controlled by a contactor (high power relay) rated at 40 or 50 amps that would be perfect for switching on your lights. Another style contactor with the expose contacts as seen in this link http://www.hydroponics.net/learn/gro...controller.asp would also work great for your needs. Shouldn't be a problem getting a Double Pole Single Throw (DPST) contactor for $20 or $25 on Ebay. Be careful that you select the contactor with a coil operating voltage that match your timer voltage. Most people like to use a 120 volts timer to switch the relay on and off, and thus would order a contactor with a 120 volts coil and make a trigger cord out of an ordinary 120 volts power cord to connect the timer to the contactor coil terminals. I prefer to have the inline fan (that will be cooling those lights running on that relay) to be powered by the same timer or trigger cord. Timers have been known to fail and I wouldn't want a situation of lights running without a fan cooling them. Glad to see you decided to use two contactors (relays) to divide the lights into two separate group of four.
Originally Posted by its a hobby honey !
Last edited by Stevie51; 07-27-2013 at 04:23 PM.
07-28-2013, 02:21 AM
Do you guys think I will be ok running a window unit and my light through a 100 foot 10 gauge extension cord on a 20 amp breaker? my light is a 1000 watt dimmable ballast with a 600w hps bulb and my a/c is a 8000 btu haier window unit I need to check the efficiency rating
Last edited by NewGreen92; 07-28-2013 at 02:23 AM.
07-28-2013, 12:42 PM
Why don't you try it and give us your feedback. I've seen people using 100 feet of 12 gauge extension cords to power a 1.5 hp pump motor to their above ground swimming pool on a 15 amp breaker, until an inspector one day happen to be driving by and notice it. Although you will be pulling a few more amps than that pool pump motor, you have an extension cord that can handle more amps and a larger breaker.
Originally Posted by NewGreen92
Last edited by Stevie51; 07-28-2013 at 01:47 PM.
07-28-2013, 02:28 PM
You should really look into a permanent installation to move that much power. Extension cords are ok for temporary measures, but are far from 'the right tool for the job'. It's too long, you can trip on it, it might have nicks already in the insulation and the conductor, etc etc..
07-29-2013, 07:46 PM
I have two spare 20 amp circuits on my main panel in garage. I already ran TWO 12/2 Romex cables through the attic, from garage to the room.
Would it be OK for me to take each cable and install a box with 4 standard 20 amp 120v plugs?
so when done, I would have two 4" boxes on the wall, total of 8 outlets, each box on their own 20 amp circuit.
I plan on plugging 1 1000 watt into each box, and splitting up the fans between the two.
so this will be a 2k grow, add everything else in, maybe 2500 - 2600w.
Will this be ok? I read alot about installing a sub panel in the room, then outlets off that..
Since I have already ran the two 12/2 cables through attic and have the two spare 20 amp circuits in my main panel, Im trying to avoid having to buy and re run more romex for 240v to feed a sub panel.
Would my plan still be safe?
Could I still do a sub panel box w a timer even though I have 2 12/2 wires, not the usual 1 big 8/3 or whatever feed wire?
Last edited by BACG; 07-29-2013 at 07:58 PM.
07-30-2013, 01:00 AM
I would properly feed a 220V sub panel and remove/save the 2 wire romex for some other project. I know it sucks to install but you'll be way happier in the end, especially if you plan on using that room for a while.
Now, you /do/ already have 4 12 gauge wires ran.. you could run a single 220V circuit with what you have. Whether or not it can safely supply the amperage is up to you to find out as it's based on distance, conduit type, number of wires in the bundle, ambient air temp, insulation type.. blah blah. But that's why they have reference books! Also, I'm not sure it's kosher to split up conductors in different conduits for 1 circuit. Seems hokey to me, but I don't see why you couldn't. I'd really prefer a single cable bundle/conduit.
Last edited by BossHoggins; 07-30-2013 at 01:14 AM.
07-30-2013, 03:31 AM
You started out with a good plan to run two 120 volts branch circuits, why all the sudden you have the urge for 240 volts? Two 1000 watts ballasts @ 240 volts will have the same sum total current (amp) draw of 10 amps through a sub-panel as would be with the ballasts placed on two 120 volts circuits as you described.
Originally Posted by BACG
07-30-2013, 09:01 AM
I had just read and been told having a sub panel in the room is safer.. But is my idea of having two straight boxes w outlets on the wall and plugging ballasts right to them unsafe? Maybe just use 2 manual timers? Should be plenty of spare amps on either 20 amp circuit. Ive been told NOT to plug ballasts straight to wall. Friend says i need a "box on the wall w built in timer" and i need to plug ballast into that.
07-30-2013, 04:05 PM
Your original plan to run two 12/2 with ground NM-B (Romex) cables to 120 volts outlets as you described is very safe. You may even be able to plug in a 5,000 btu air conditioner (nothing larger than 5,000 btu) to one of the outlets if needed. A sub-panel is only necessary when you are running more 1000 watts ballasts in that room, so bear that in mind if you plan to expand the lighting in the future. Yes you will need two timers (one for each ballast) for now.
Originally Posted by BACG
Last edited by Stevie51; 07-31-2013 at 01:00 AM.
07-30-2013, 09:15 PM
His total amp draw going to the room would be double on 110V, not the same.
I say anything pulling a kilowatt or more should be 220V. Less heat in the conductor.. you can use a smaller gauge wire.. The advantages are many. You can pull 110V off the panel too..
I thought 12/2 wire meant there were only 2 conductors in the bundle. If there is a 3rd for a ground fault.. yeah, that's fine if you wanna keep them 110V. I wouldn't move 2KW anywhere without an isolated fault circuit though.
Last edited by BossHoggins; 07-31-2013 at 02:29 AM.
Tags for this Thread