MH ballast not firing lamp all the way.

PaulErik · Oct 26, 2020

The Radium 250W is designed to operate on a HQI ballast. This combination typically gives the best performance.

The problem now is lamp manufacturers are having to alter lamps to meet certain global standards. This has made some lamps more sensitive to operating and starting parameters. In this case many German lamps have removed Kr-85 and lowered the mercury dose. Making starting more difficult.

whitelightning77 · Oct 26, 2020

PaulErik said:
The Radium 250W is designed to operate on a HQI ballast. This combination typically gives the best performance.

The problem now is lamp manufacturers are having to alter lamps to meet certain global standards. This has made some lamps more sensitive to operating and starting parameters. In this case many German lamps have removed Kr-85 and lowered the mercury dose. Making starting more difficult.

Ok, so then in my case what do you recommend? Everything has been working just fine for over a year, till about 2 days ago. Through the apex ot looks like it doesn't want to start at all, but when plugging it directly into a wall outlet, it flickered, but after about 5 mins it finally kicked on.

PaulErik · Oct 26, 2020

Your setup is known to be a little sensitive.

Check the ballast disconnect for signs of arcing. One person I know had a faulty receptacle on the ballast. It was leaking the high voltage pulse.

You could change the ballast to an electronic ballast as well but I typically don’t recommend electronic ballasts for European 250W halide lamps.

When the setup is sensitive little things like voltage drop to the ballast can cause even more issues. Your magnetic HQI ballast requires the input voltage to be within +/- 5% at 120V.

whitelightning77 · Oct 27, 2020

Ok, so I did a little more deductive experimenting last night. Seems like Paul and Dirk might be up to something.. When I came home from work the light was still off when it should have been on. So, I removed about a 7ft section of cable to shorten the whole length. Turned it on and nothing. Then I took the cable and plugged it directly into the wall outlet bypassing the apex (but still sharing the same circuit) and nothing. Then I took the cable and plugged it Into a different outlet on the other side of the room and it fired up. Did the same test twice and it reacted the same way. So what would be the consensus? Everything else on the apex is working fine to my knowledge. Is my receptacle going bad and should be replaced or is the ballast (or one of its components) still the culprit?

whitelightning77 · Oct 27, 2020

PaulErik said:
Your setup is known to be a little sensitive.

Check the ballast disconnect for signs of arcing. One person I know had a faulty receptacle on the ballast. It was leaking the high voltage pulse.

You could change the ballast to an electronic ballast as well but I typically don’t recommend electronic ballasts for European 250W halide lamps.

When the setup is sensitive little things like voltage drop to the ballast can cause even more issues. Your magnetic HQI ballast requires the input voltage to be within +/- 5% at 120V.

How can I check for arcing on the ballast receptacle?

SebastianReefer · Oct 27, 2020

oreo5457 said:
For 3x the normal cost of a capacitor.. they better..

It might cost more but the Hamilton is better quality better parts

PaulErik · Oct 27, 2020

Did you shorten the cord from the ballast to the lamp?

How many things are on that same circuit? You should add up the equipment and make sure that circuit isn’t overloaded.

Arcing will leave burn marks and melt parts. If the ballast has a poor connection to the lamp anywhere it can arc. Sometimes can be heard as well.

whitelightning77 · Oct 27, 2020

PaulErik said:
Did you shorten the cord from the ballast to the lamp?

How many things are on that same circuit? You should add up the equipment and make sure that circuit isn’t overloaded.

Arcing will leave burn marks and melt parts. If the ballast has a poor connection to the lamp anywhere it can arc. Sometimes can be heard as well.

Yes, I removed about 7ft. On that circuit is what I have running on my tank via apex, (2x250w halides. A skimmer. Return pump. An led for my fuge and 2 brs dosing pumps) and 2 modems and a router. But like I said, this just started happening a few days ago.

PaulErik · Oct 27, 2020

If nothing has changed I would look into replacing the bulb. With the cord shortened and still not working properly I would look into replacing the ignitor on that ballast. The ignitor can get weaker overtime especially if the ballast is left running without a lamp firing for a while.

whitelightning77 · Oct 27, 2020

PaulErik said:
If nothing has changed I would look into replacing the bulb. With the cord shortened and still not working properly I would look into replacing the ignitor on that ballast. The ignitor can get weaker overtime especially if the ballast is left running without a lamp firing for a while.

I have extra bulbs, and also swapped out the other working bulb as well. So 3 blulbs total. they are all doing the same.

PaulErik · Oct 27, 2020

You tried a new bulb? If nothing has changed in your setup and it suddenly started having problems then it has to be the ignitor is getting weak. You also shortened the lamp cord which should have helped.

The ignitor on your ballast is a semi parallel (impulse) type, uses the ballast’s secondary coil as a step up transformer. You want to get the same ignitor. These are typically not interchangeable.