Question about older M80 ballas

[jdthomas]

I've got an older Hamilton Belize Sun fixture, with M80 ballasts that I've used for a number of years.

Today I started installing my new Apex, and upon plugging in my mh lights, had quite a surprise. The power draw on one was just over 600 watt/7.7a, and the other was over 500w/6.5a. This is not startup, the lights have been running for hours.

I'm guessing that the ballasts are just bad, but it's been in continuous use for years, with no problems firing bulbs. The bulbs themselves are year old 14k pheonix bulbs that despite the power draw have no visible burn spots on the inner bulb. Tried another set of bulbs with no change.

The one ballast did trip the breaker on my old Reefkeeper outlet, but after I moved it, all seemed well. So the problem has probably been going for a while

Any thoughts? The ballasts shot? Any good eballasts that will drive hqi bulbs?

 

[Bryan]

It's quite likely the capacitors have aged and out of spec. I believe on certain ballasts (CWA) this can cause a increase in current. I have a HID troubleshooting guide I can forward you.

 

[jdthomas]

Looks like you may be onto something here. I opened the box to check the capacitor. When I discharged it, there was no charge. Ohmmeter gives a low steady resistance. That seems from what I've found online to indicate a short.

Now comes the joy of finding a proper replacement.

 

[moondoggy4]

Have you reached out to Hamilton?

 

[Bryan]

Well you really need a proper capacitance checker with ESR capability to properly check a capacitor. But almost any industrial lighting store will sell replacements or Ebay, just need the proper voltage rating and the cap value. Typically etched on the side of the can. Think they run about $10.00.

 

[jdthomas]

Yeah, I put an email in to Hamilton. They show replacements on their website. I'll also check local electrical places Monday morning.

It's a place to start at least. Thanks folks.

 

[Bryan]

Yes, try the cap, test, if it drops the current you lucked out. It's pretty rare for a ballast transformer to open or short. Something generally goes has to go real wrong. As I understand you can actually short circuit a HID ballast. Usually when something goes wrong it's connections, bulb, cap or ignitor (if one is used).

 

[oreo57]

http://www.acuitybrandslighting.com/Library/LL/documents/SpecSheets/TD-110.pdf

 

[jdthomas]

I stopped by the electrical supply place on the way home and picked up a cap. It's a little different spec, but they said it would work. Upon install, the lamp fired and is holding steady at about 390 watts. A far cry from the 600w it was pulling before. Still not great, but it won't send my apex into a fit.

Thanks for the insight.

 

[Bryan]

Hard to say as bulbs all have their own specs, but most bulbs for a M80 ballast are around the 3.0 amp mark which works out to around 360 watts. In the ballpark and aging bulbs apparently will draw a little more current.