Need Help Identifying cause of short in VHO lighting

[Mickey]

I could really use some help here. I understand just enough to be dangerous. :worried:

Current issue:
2 6 ft VHO actinics on an Ice Cap 660 ballast were running fine. Timing controlled by an Aquacontroller Pro 3. They were fine up to yesterday then went out in the evening sometime. I checked the circuit and it was fine. I noticed nothing else on the same controller for the AC3 was working and found the fuse had blown. Changed the fuse and it immediately blew again when I plugged in the same pair of VHO's

Suggestions?

Background: This is one pair of VHO's. I have another two VHO's on a separate 660 ballast, one is 6ft and one is 4ft. That one has been turned off since bulbs were changed last month because one if the bulbs wouldn't light and I assume I have a wiring problem. I am planning on replacing the end caps on the bulb that won't light and hope that one will be okay.

Thanks for the help.
Mickey

[Steve S]

Have you tried replacing the bulbs...maybe on of the bulbs has a short in it?? Just a thought.

[Mickey]

The bulbs were fine for 4-5 weeks. If there was a short wouldn't it have shorted out right away? I do have one extra bulb plus the old bulbs.

Update - I changed out the end caps and the bulbs are lit again (let's call this VHO1), but one is much dimmer than the other. Readings on the continuity test were fine. So, what could that mean?

I also ran the continuity test again on the other ballast (the one I had kept off - lets call it VHO2) and the readings were way high on one bulb and no readings on the other. I assume this means the problem is with the bulb with the high readings.

I'm going to leave it off and will try changing those end caps unless someone has another idea to give me.

Mickey

[Mickey]

Update. When I went to bed last night, the VHO's from VHO1 ballast were still on. Got up this morning and the fuse in the Neptune System controller is blown again. So obviously there is still a problem.

I just don't know what to do now.

Mickey

[sbeason]

Change your bulbs. I had this problem with my 660 and put new bulbs in and it fixed the problem.

[Mickey]

sbeason - Thanks for the suggestion, but these are brand new bulbs. The problem started with the new bulbs. I really don't want to spend another $120 on bulbs to replace ones that are only 30 days old.

[tkeracer619]

I would guess its a ballast issue. The fuse isn't going to blow from a short in the wiring post ballast. I might be wrong but if its the fuse in the dc8 then its a ballast issue.

[Mickey]

I have another ballast that is brand new so I'll try that. Thanks.

Mickey