MH ballast hum?

emusinky

Member
I just got my light hung, turned it on, and the ballast makes the worst humming noise. Is that normal? I bought this light off the 'bay' and it's called Indoor Sun. The noise would drive me crazy. It's 400 w with a 14000 bulb. I know they get warm, but can I insulate the noise?
 
S

shrimpy brains

Guest
Mine hum when they first come on, but once they come up to full power, they are quiet.
 

emusinky

Member
I only left it on about 10 minutes since it isn't enclosed yet and I worried about my dog and cats eyes. I will work on the canopy in the morning and hopefully it will quiet with time. Thanks
 

scsinet

Active Member
Different ballasts make different amounts of noise. Some noise is normal. Cheaply made ballasts with core laminations that are not well laquered or coils that are not shimmed properly can hum much worse. Not much you can do if you've got that problem.
 

scsinet

Active Member
Not necessarily. Just give it time. Sometimes it just goes away. It may also be a matter of letting the lamp warm up completely as shrimpy said.
 

stanlalee

Active Member
depends on your interpretation if its normal or not. I had dual magnetic ballast and they hummed very noticeable and it really didn't get quieter once running, we just got used to it until the lights went off and it was suddenly quiet in the room. this was a major brand (sunlight supply blue wave). typically magnetic ballast hum. Its probably normal but if you werent expecting it or didn't know I guess you might find it terribly annoying regardless of how much hum it is or isn't making..
 

emusinky

Member
I just ran it for an hour. It seems to have gotten louder!
It sounds like a smoke alarm. I didn't want to leave them on too long for the first day. It wouldn't be so bad if I wasn't retired and home with it all day. My BTAs were doing the happy dance today after a few months with PCs.
I was waiting for the weather to cool before I started up the MH. Now, I don't know what to do. It will be some time before I can afford new lights.
 

scsinet

Active Member
Originally Posted by EmusinKY
http:///forum/post/3156987
I just ran it for an hour. It seems to have gotten louder!
It sounds like a smoke alarm. I didn't want to leave them on too long for the first day. It wouldn't be so bad if I wasn't retired and home with it all day. My BTAs were doing the happy dance today after a few months with PCs.
I was waiting for the weather to cool before I started up the MH. Now, I don't know what to do. It will be some time before I can afford new lights.

What do you mean like a smoke alarm? Is it humming loudly or making a screeching or whining noise?
 

emusinky

Member
A very loud hum. I wouldn't hear the phone or if someone knocked at the door. I had an old smoke alarm that sounded just like it. I bought two of these lights. Maybe the other one isn't as bad.
 

scsinet

Active Member
Originally Posted by EmusinKY
http:///forum/post/3157066
A very loud hum. I wouldn't hear the phone or if someone knocked at the door. I had an old smoke alarm that sounded just like it. I bought two of these lights. Maybe the other one isn't as bad.
Check the ballast enclosure and make sure all of the nuts and bolts are tight. You may need to take it apart to find all of the nuts and bolts.
 

emusinky

Member
I was wondering if I could mount the ballast outside the house in a cabinet. On the unit it says: suitable for operation in ambients not exceeding 55 C. It doesn't say how cold it can be. I just noticed a date on it. 12-29-89. That thing is 20 years old!
It was re-manufactured. I guess it is a case of 'You get what you pay for'. The light looks great on the tank. Too bad the sound drives me crazy.
 

emusinky

Member
It's all tight on the outside. It has a hole in the middle you can see through. Is that normal? What will I find inside?
 

scsinet

Active Member
Originally Posted by EmusinKY
http:///forum/post/3157080
Is it a dinosaur?
What has happened here is that someone got a hold of a whole bunch of metal halide highbay fixtures. These are the things you'll find in warehouses and stores, in high ceilings.
They cut/removed the reflector assembly (which is where that hole is you talked about), drilled a couple holes for cable clamps, and rigged a powercord/remote reflector, made up a company name, and started selling them on that famous auction site.
The problem is that these ballasts are not designed to be quiet. They are designed to run in a high ceiling where the noise won't be a problem.
The good news is that you can just replace the ballast assembly with an off-the-shelf unit designed for aquarium use if you are unhappy with the noise.
Mounting it outside would probably work, if you could protect it from the elements. The cold shouldn't bother it.
 

emusinky

Member
I thought they sounded a bit like the factory. Thanks for your help!
I'll work with it for now. I think I will put it outside. It's on an outside wall and I was thinking of making a vent (for summer) to go with it. I just turned it right side up, thinking about what you said about it being on the ceiling. It's not as bad but it will still be moving out of the house.
 

bmkj02

Member
I bought something exactly like this from a local warehouse that was upgrading their lights. They were selling them for $25 each and had more than 200 of them. When I got them I stripped off the light assembly which is the reason of the center hole like SCSInet said. I split it open to see what kind of ballast they had and they were the Advance 400w ballast. After hooking them up one of them was silent and they other one was loud like you mentioned. The humming noise went up and down. Was real loud at first for several months but I kept using them. They started getting quiter and now I barely hear it.
If they are that loud in your case I hope the neighbors dont mind for keeping them outside.
 

emusinky

Member
My nearest neighbors are 1/4 mile away, so no problem.

I was in the kitchen trying to avoid the noise and it suddenly stopped. I ran back to see what happened and everything is fine!
The light had been on for about 90 minutes straight this time. I sure hope it stays like this!
Thanks all for the help.
 
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