Light flip flop relay size? Going to shutdown ballast between flip

[vertstyle]

Going to do a flip flop with one 400 watt hps.
Seems like 30amp 600v rated relays like this are what people are using.

Most of those people are leaving the ballast on during the flip.
I'm planning to use a timer to shutdown the ballast between flips to save the relay contacts.
I don't need that big of a relay right? Anyone know what I do need? Something I can grab at radioshack or a local supplier would be great.
Thanks.

 

[Olyver]

That relay is exactly what you need. Only place you'll find them is electrical distributor or online.

 

[vertstyle]

Good to get a reply from you, a lot of what I've learned about flip flops was in threads you were involved in. Thanks.

 

[R1ridah]

Careful...

I am sure you are already aware of this but i guess it doesnt hurt to remind folks... when doing so, make sure to wire the ballast to shades correctly so that you do not have a 120V stun gun. better safe than sorry.

 

[Jalisco Kid]

Good relay contacts are rated in the million of make/breaks. I do not think you have to worry about saving your relay.JK

 

[vertstyle]

Good relay contacts are rated in the million of make/breaks. I do not think you have to worry about saving your relay.JK

If the ballast is on during the flip the contacts arc and end up pitted or stuck together. I've seen people using that relay say it has happened, so I figure shutting off the ballast should make the relay last forever.

 

[Olyver]

The arcing is caused by emf (energy) in the bulb that has to discharge. Shutting off the ballasts allows the bulb to discharge back through the capacitor, it's instantly. Then turn the ballast back on. With a PLC, you can control power for the ballasts and flip relays, down to 1/100 second. Within half a second, you could shut off ballasts, allow discharge, switch lights, turn ballasts back on. They're a several ways a flip can be controlled. If you are doing a zig-zag pattern with your flip, only half the lights are on in each greenhouse. If each greenhouse has 8 lights, and only 4 are on in each one, then instead of switching all of lights at once from off-on and on-off, do one light at a time, a couple minutes apart.

As for the relay, it's doesn't have to be NTE, P-B, Omron, Siemens, etc., it's the same dpdt relay, 600V rated contacts. Some flip manufacturers will say they have the "best" relay, they're all the same.

 

[vertstyle]

I'm just testing out the flip on one ballast so far.

What kind of wire should I use to make the cord between the ballast and socket on a magnetic 400 hps?
Would a 12g extension cord be fine? Since it is not digital I don't need a shielded cord right?

 

[xX Kid Twist Xx]

this box here costd a little more. then the one you are using. but it has to do with the thread so i figured id throw it out there.

 

[mrdizzle]

The arcing is caused by emf (energy) in the bulb that has to discharge. Shutting off the ballasts allows the bulb to discharge back through the capacitor, it's instantly. Then turn the ballast back on. With a PLC, you can control power for the ballasts and flip relays, down to 1/100 second. Within half a second, you could shut off ballasts, allow discharge, switch lights, turn ballasts back on. They're a several ways a flip can be controlled.
.

does that cause any ballast damage, turn off then right back on, or is it only the bulbs you need to worry about

 

[vertstyle]

this box here costd a little more. then the one you are using. but it has to do with the thread so i figured id throw it out there.

That's what I'm talking about, it's just an already wired and completed version. I think I've seen that same one a little cheaper on ebay as well. (edit:$125 on ebay) If anyone has one I'd love to know what relay it uses.

I figure I would be spending $75 or so on building one so that isn't really a bad price.