DIY four light controller relay question?

[1budman1]

So I saw a link that MEDIVAX put up to build a four light controller. It sounds like a good project I'm having trouble with the relay. I've bought two now and they don't switch like they're supposed to. Has anyone built one of these and what relay did you use. Anybody, anybody?

[GaGrown]

It's a 30 amp power relay.

Ga Grown!

[GaGrown]

I found this. It should help.....

Ga Grown!

Anyone that has more than two 1000 watt lights in their home has probably run into the problem of how to supply power and turn them on and off. A standard 120 volt circuit in your home has a 15 amp rating, that means one light. Note: I will be using the term "120 volt" and "240 volt" to describe the two different types of circuits we will be working with only because that's the term the ballast manufactures use. They are often referred to as "110 volt" or "220 volt", actually if you measured the voltage with an accurate meter a 120 volt circuit often will be less than that an can vary. A 1000 watt light draws about 9.2 amps at 120 volts (1100 watts / 120 volts = 9.17 amps). See this page for other ballast wattages. On a 240 volt circuit the amperage is 4.6 amps (1100 watts / 240 volts = 4.58 amps), so when running multiple light systems, it's easier to wire them for 240 because you can use smaller wire.

In a 120 volt circuit, the power cords have three wires; a black, a white and a green. The black is the "power" or 120 volts, the white is the "common" or "return" and the green is the ground. In a three wire 240 volt circuit, like we use for grow lights, there is also a black, white and green. The black and white are both 120 volts (180 degrees out of phase with each other) and the green is the common and ground. In a 240 circuit we are splitting the load between two wires.

The problem for most of you is that you just can't go out and buy a timer that you can "plug in" four lights. I have looked at many different lighting controllers for the hydroponics industry and found that most are $200 to $300 for what amounts to a $30 relay in a box with some outlets. I know many of you like to build this stuff on your own, so I setout to build one of these with safety and low price in mind and to get as much of it from Home Depot as I could. I know that some of you have built controllers based on the Intermatic T103 timers like this one, they will work for four lights but what do you do when you have eight or twelve lights and you want them to turn on at the same time? The answer is a relay.

A relay works like a light switch, it connects and disconnects two wires. The difference is that instead of flipping the switch with your finger, a relay has a coil that when power is applied, it makes the connection. The advantage of this is that the coil requires only minimal current. The one I am using draws 85 milliamps. That means I can control quite a few of these relays with one 15 amp timer. 15 amps / .085 (85 milliamps) = 176, or 176 four light controllers. I don't know if anyone has 704, 1000 watt lights, but if you did you could turn them all on with a $10 Home Depot timer! One problem though, you still need 176 different 30 amp circuits..... On with the project.

[1budman1]

Thanks for the replies guys. GaGrown that's the link I've been following. There's a couple of different 30 amp relays out there. The first one I got was a 240 volt 30 amp DPDT "double pole double throw". It didn't look exactly like the picture since it had double contacts, but I didn't thinl it would hurt. I hooked up the coil to a pigtail and plugged it into a 110 outlet it buzzed and viabrated. My wife probably would have liked it, but I went back to the store and got a 240 volt 30 amp DPNO. It looked just like the picture. I once again hooked up the pigtail to the coil just like the instructions and it humms. Now I'm no electrician, but I thought I could handle this. There's one more heavy duty relay available. The only difference from the one I just got is it is noted to be a 208VAC coil. Any input?

[GaGrown]

A double pole double throw switch, make connection 1 pole at a time as to where a double pole single throw switches 2 poles at 1 time.I think that would be the relay you would need.Stick with the 240,cause you will be using 220,correct? Let me ask my Tech buddy... I'll get back to you on that this evening.

[1budman1]

My first thought was double pole double throw too. But it seems more like the flip flop style. At rest it is making contact with one set of poles. When the coil is activated it flips to connect the other poles. It doesn't look like the switch in the article. I thought cool I can later use it as a flip flop if I want, and right now at rest I'll just have nothing there. But when I hooked up the coil and plugged it in it buzzed. I'm wondering if I'm supposed to be usiing 220 to activate the coil. But then I can't use a digital timer to activate it which is half the reason I'm doing this. So I don't have to be concerned with power outages and my timers. Let me know what your buddy thinks. Thanks for troubleshooting this with me.

[GaGrown]

Hey Budman,
The relay you are trying to use,should be a contactor and not a relay switch. The contactor you need has a built in coil.The relay you were wired too,had to much current.Not sure about the digital timer. I know the Intermatic would handle the job!If your power went out you would have reset it.The digtal is the whole reason for this,I know.We can get your lights on! I had a contactor and left it on the shop table. I was gonna post some pics of it for ya.. Sorry! Dawg... I did get the info you needed.

[1budman1]

I called tech support. I was looking at the wrong numbers in the catalog. I was getting the ones that switched with 220. Swapped it out for a 110 coil switched 220 current model one. Now I'm in business. Thanks for looking into it, that was pretty stand up!

[GaGrown]

Look at the post about the digital timer. Intermatic. Your welcome! Not a problem...

Ga Grown!

[koalphin]

I am trying to build the controller box as well and looking for relays, I found this one at ACradiosupply.com it is part # R04-11A30-120. DPDT relay. $18

This is the correct one I believe can anyone confirm this?