I have a grow light system with four shelves (or whatever you would call them) that is about 40 years old. It has a total of 12 lights, and all of the lights work fine except for three.

The three are all on one shelving unit. Each shelving unit has two sets of two lights, with each set run by one ballast. On one ballast (Ballast 1) one of the lights works fine, and the other one not at all. This ballast is very warm. On the other ballast (Ballast 2) the lights are kind of dim. This ballast is not the least bit warm.

The ballasts in the units that are working fine don't seem to be warm, maybe just a little, but I'm not totally sure because I haven't taken those units apart; I can only feel the edge.

All the lights have been tested fine in other shelving units.

Everything is original.

How would I go about troubleshooting this? Tomato planting takes place in about 4 weeks!!

Other details:
Most of the lights are pretty old, but they haven't been used much. They are 40W and 48 inches long.

The ballasts are big brown things about 8x2x1 inches, and made by General Electric. They have the following things on them:
Class P 8G1022
120 V
60Hz
80 Amps

 

Replacing the basalts id the usual troubleshooting procedure and you seem to be to that point. You may want to replace the magnetic ballasts with electronic ballasits. If you do you will need to follow the wiring guide on the new ballasts not how the old one was wired.

Class P 8G1022
120 V
60Hz
80 Amps

Is that 80 watts not 80 amps? Are the bulbs eight feet long? Does it say T-12 on the bulbs?

 

Ah, it says .80 amps. I don't see t-12 on the bulbs.

Are there any things to look out for when replacing the ballasts?

 

How long are the bulbs? What is written on the bulbs.

 

Replacing ballasts can be as expensive as replacing the entire lighting unit(s). I have a similar set up for wifey to seed her plants. You will get a lot of weird looks at the box store when you buy a dozen grow lights. I even had our local sheriff call one night asking what I was growing. Seems the DEA helicopter had done a flyover and their spectrum meter indicated my house was lit up like a fire.

 

The lights are a mixture that as far as I know are just regular 48-inch florescent lights. I didn't look at all of them, but the ones I looked at had one of these on them:

F40/CWX 40W
F40/CW 40W
F40CW/RS/EW-II 34W

 

So your best, cheapest, bet may be to replace the complete light assembly with a four foot shop light. Probably cheaper then a new ballast. The t-12s which is what youi probably have are being phased out so if you can find T-8 shop lights you will have a brighter more efficient light that may save you a little money to operate.

With out seeing your setup I can't say how easy switching out the whole light would be but if you need help on that post a picture and someone may have some ideas. http://www.doityourself.com/forum/li...-pictures.html

 

You might also just want to steal a ballast from a cheap T-8 shop light and throw the housing away.

 

Here are a couple of pictures:

P2190315.jpg picture by pporto_522 - Photobucket

P2190316.jpg picture by pporto_522 - Photobucket

One is the whole grow light assembly. The other is the top unit upside down and with the cover over the ballasts removed.

I don't necessarily care about cheapest. Whatever is best long term is all I care about. The assembly itself will last decades. The lights are used about 12 hours a day for about 5 weeks.

 

Instead of shop lights you might consider four bulb troffers for suspended ceiling.

 

Interesting, but I have way too many projects underway.

In order to use my existing shelves, what ballasts and lights should I get? What would be a good source?

 

Easiest place to go is Home Depot, but you can get them from almost any home store or hardware store.

If you want to convert fixture to T-8 lamps (you will have to buy new lamps also, about $3 each but will give you more light with less watts) get this: 4-Lamp T8 4FT Electronic Resi 120-Volt-71038 at The Home Depot (you will only need one for 4 lamps)

Otherwise you will need two of these (one per 2 lamps) if you want to stick to T12: 2-Lamp Rapid Start Ballast for 4 ft. T12 Fluorescent Lamps-74473 at The Home Depot

I seam to remember getting some electronic ballasts that will run 4 - T12 lamps from HD but I can not find then on their site. Maybe they are no longer available or they just have them at some stores.

 

Well it sounds to me like I should start switching over to T-8 bulbs, and use my existing T-12 bulbs in the units with the old ballasts, and then convert those as they fail.

 

I'm with Tolyn's suggestion of replacing the ballast. You also need to replace the cord with a grounded one.

 

Well, it appears that the bulb housing is also the shelf for the plants. So I think that replacing just the ballast is the way to go. I don't know if you will be able to change the bulb type with your fixtures either. If home depot isn't working out for you, try Grainger.com.

 

While T12 bulbs will work with a T8 ballast it will greatly shorten the life of the ballast AND bulbs. I suggest saving the good T12 bulbs for other fixtures whose ballasts are still good but the lamps have failed. Then use the proper bulbs (T8) with the new ballast. It will be better in the long run. Marking the fixtures with either "T8" or "T12" will tell you the proper lamps for each fixture.

 

Thanks much for the help, everyone. I'll let you know the outcome.

 

Seems pretty straightforward, but I thought I would show you guys my wiring before I went live.

Also, the bulbs I bought say F32T8/DX, but the only two 32 watt bulbs mentioned on the ballast label are F32T8/U and F32T8/DX. Is that OK?

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That should be fine. Just follow the wiring diagram on the ballast and your golden!

Did you buy a 4 lamp ballast?

 

I bought the ballast that you recommended: 4-Lamp T8 4FT Electronic Resi 120-Volt-71038 at The Home Depot

 

You likely have this done, but if you are confused, then I just wanted to let you know that if the diagram shows one wire going to the lamp holder and you have two, you just splice them all together.

IE: In your pictures I can see you have two reds or two blue wires coming off of one lamp holder. Just splice them together and then connect them to the single red or blue off the ballast.

Good luck! Let us know if you have any issues.

EDIT: I see you have it installed already in the picture. Looks correct.