How do you run two rooms from one ballast?

I saw on a thread by northernfarmer Here where he says that he runs two grow rooms off one set of ballast by using switching relays. How do you do this? (as in what kind of relay?)
http://www.icmag.com/ic/showpost.php?p=1034566&postcount=25

You just need a 250 volt dry contact relay that will run off a timer. He is switching the power back and forth between the lights with 2 relays and 2 timers. One grow runs 12 on 12 off and the other runs the opposite sched, but still 12 on 12 off. When 1 room is dark, the other is light and vice versa.

Conceivably with one 600 W ballast you could run 2 separate flowering rooms with light movers so it could cover a total of 64 square feet of grow area, which is 4 times the amount a standalone could flower. Assume a SOG style Grow with each plant yielding an average of 1 ounce. 1 plant per square foot could net you 4 pounds of nugs. Food for thought.

NoDrama said:

You just need a 250 volt dry contact relay that will run off a timer. He is switching the power back and forth between the lights with 2 relays and 2 timers. One grow runs 12 on 12 off and the other runs the opposite sched, but still 12 on 12 off. When 1 room is dark, the other is light and vice versa.

Conceivably with one 600 W ballast you could run 2 separate flowering rooms with light movers so it could cover a total of 64 square feet of grow area, which is 4 times the amount a standalone could flower. Assume a SOG style Grow with each plant yielding an average of 1 ounce. 1 plant per square foot could net you 4 pounds of nugs. Food for thought.

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Mad props for the answer! And what a bit of food for though that is. hmm!

interesting idea hadnt thought about it very simple things like this many people overlook are quite beneficial

NoDrama said:

You just need a 250 volt dry contact relay that will run off a timer. He is switching the power back and forth between the lights with 2 relays and 2 timers. One grow runs 12 on 12 off and the other runs the opposite sched, but still 12 on 12 off. When 1 room is dark, the other is light and vice versa.

Conceivably with one 600 W ballast you could run 2 separate flowering rooms with light movers so it could cover a total of 64 square feet of grow area, which is 4 times the amount a standalone could flower. Assume a SOG style Grow with each plant yielding an average of 1 ounce. 1 plant per square foot could net you 4 pounds of nugs. Food for thought.

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You are on it when it comes to electrics....based on a couple posts. But your crazy cubic math on yields.....whoa....if your above statement is true what is my yield with this little flower room-3kw and 96 square feet (approx 3 plants per square) All on light rails too

Its perfect world thinking, but 1 sq foot =1 ounce is average yield, i currently use less than 1 sq foot per plant and get plants that have more than 1 ounce on them. This would assume you were using the entire 64 sq feet of space ( Square not cubic) to flower with, no other space for anything else, which in the real world we know that some of that space would get used for other things.

In your situation I would say 10 pounds + is more than possible. Since you have 3 plants per sq foot then your yields per plant won't be as high as mine so I couldn't say with any real accuracy, but your overall yields should be better.

I am sorry my math was frigged up on my trays. I have 96plants in a 24 ft are=4 plants/ft2, my whole tray is 8x4 but I don't use the last foot on either end.

Still the point I was getting at is yield is really all about watts. I could grow-1, 10 or 100 plants under a 1000w lamp and get a kilogram out of the grow no matter how many there are. Veg time just needs to be changed to suit number of plants.

Just my 2cents

NoDrama said:

In your situation I would say 10 pounds + is more than possible.

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Thats the goal every 60 days...3-3.5 every 20 days-but that means 1.5 grams per watt--possible but requires perfect temps and RH at all times........Sorry Stinkbud

You can buy flip floppers from most hydro shops. Prewired and ready to go so you can run a ballast 24 hr with 2 bulbs.

a read about a guy who has one grow room which holds 4 plants but he has 8 on the go. he has a 250 hps on 24 hours. he has 4 plants in a cupboard with a black sheet covering them and four in the room under the light, every twelve hours he switch,s the plants meaning he can grow 8 plants under one light in the limited space he has.

quite clever but you dont know wat kinda stress you could be causing to keep moving them, as the humidity and temps would most definately be different in the cupboard and the growroom

BCtrippin said:

You can buy flip floppers from most hydro shops. Prewired and ready to go so you can run a ballast 24 hr with 2 bulbs.

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Where could I buy them online, or is there a company and part number that I could make work for a good google search?

Really, i'm interested in 3-4 of these for my own project.

ugmjfarmer said:

Where could I buy them online, or is there a company and part number that I could make work for a good google search?

Really, i'm interested in 3-4 of these for my own project.

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All you need is any relay. There is set of contacts on a relay that turns on or off several other NO(Normally Open) and NC(Normally Closed) contacts on the relay itself, via electromagnetic coil. The NC contacts allow current to flow when there is no power applied to the coil(hence normally closed). When power is applied to the coil, the NC contacts open, prohibiting current to flow, or turning them off if you will. In turn, applying power to the coil also closes the NO contacts and then allows current to flow in them, when they normally would not(hence the normally open). The coil acts like a switch that turns one light off and another on simultaneously. Just wire one light directly to a set of NC contacts, and another to the Coil itself. This way, when the light wired to the coil turns off, the NC contacts will turn on, and so will the other light. When the coil is on, the light wired to the NC contact should shut down. The one wired to the coil must be operated by a timer, but that should be all that you need.

Added: I forgot to mention that for this to work you would have to wire the light, the timer(breaking the circuit and shutting the coil off every 12 hours), and the coil contacts all in series with the output of the ballast. The output of the ballast would also have to be in series with the second light and the NC contacts. Wiring two circuits powered by the same source will not cause problems because only one of the circuits will be operating at any given time, one light or the other. Sorry this was pretty important information, oddly enough I seem to remember things I've forgotten after I get stoned hahaha.

Added again: by any relay I meant any 120 volt AC relay rated to handle your circuits power consumption.

Keep in mind that a HPS will have a 1K-5K volt starting spike. Can weld the contacts shut. (probably not, but I'd change out the contractor on a regular basis). And they ain't cheap ~$40+ I also wouldn't go solid state relay, they would be more vulnerable to the HV spike (though poor little gates))

you can get a very expensive one here that does 6 ballasts and 12 lights but they do make ones that do 1 ballast and 2 lights you just gotta hunt for them
http://www.htgsupply.com/viewproduct.asp?productID=53285

flips are kool mmmmkay but ballast can get hotttttttttttttttttt

Be careful with just any relay, your gonna start a fuckin fire....It pisses me off when people tell people to just jerry rig shit together, especially when the people asking usually have absolutely NO IDEA about wiring up a ballast.

http://www.progressive-growth.com/timers_timerboards_relays_flipflops.php

Theres some ballast relays on there, theres even one that can run 4 ballasts (8bulbs)



If you dont have fans blowing on your ballasts to keep them cool you shouldnt be growing weed....Common sence man....

BCtrippin said:

Be careful with just any relay, your gonna start a fuckin fire....It pisses me off when people tell people to just jerry rig shit together, especially when the people asking usually have absolutely NO IDEA about wiring up a ballast.

http://www.progressive-growth.com/timers_timerboards_relays_flipflops.php

Theres some ballast relays on there, theres even one that can run 4 ballasts (8bulbs)



If you dont have fans blowing on your ballasts to keep them cool you shouldnt be growing weed....Common sence man....

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Why does *everything* start/cause a fire?

The HV spike is short, ms if not ns. If a set of contacts do get welded shut, wheres the fire coming from? Only one light will be on anyways. The contacts won't 'single phase' either, its one set or the other. (I work with these things all day long, along with 25KV)

Open up the cord from your ballast to lamp. I bet its rated at 600V.

A ballast sitting in free air outside the grow room is fine. You think all them factories have fans blowing on *each* ballasts sitting up at the ceiling/lamp? (Its warm up there in august in southern Texas)

If the ballast is UL rated, its meant NOT to be fan cooled and is *insured* by UL.

LOL!

yup general population is proof common sense isn't.

BCtrippin said:

Be careful with just any relay, your gonna start a fuckin fire....It pisses me off when people tell people to just jerry rig shit together, especially when the people asking usually have absolutely NO IDEA about wiring up a ballast.

http://www.progressive-growth.com/timers_timerboards_relays_flipflops.php

Theres some ballast relays on there, theres even one that can run 4 ballasts (8bulbs)



If you dont have fans blowing on your ballasts to keep them cool you shouldnt be growing weed....Common sence man....

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You know what's common sense, how to spell sense hahaha. Now that I'm done insulting you (my apologies I couldn't resist, I love grammar errors), I want you to know that you're right. I should have mentioned that it would have to be a 120v AC relay that can handle the required power consumption. Sometimes I make the mistake of assuming that type of information is common sense. The circuit I explained is a VERY simple one though, I assure you. You should see some of the shit I deal with in school... The description of how a relay functions is pretty confusing, but I don't think there is an easy way to explain it. Last but not least, those who don't know what I'm talking about, should also have the common sense not to attempt it.

If you don't know what a "series " circuit is as opposed to a "parallel" circuit you should not try this either.

Guys, no need to panic. I took electronics in college. I understand ohms law, series-parallel and all that jazz. I've been shocked a few times in life, but not in the last 12 years. Big thanks for finding who has a 4 ballast flip-flop for sale. the price is well within reach of my medical grow op costs.