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View Full Version : Metal halides not so bright???


tquick
09/18/2008, 10:28 PM
Ok i posted this over at TRS in regards to repairing a magnetic ballast such as a pfo ballast. So here it is for us over here :)
Metal halide with the magnetic coils.

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Ok thought i would post this just in case some peeps might need some help. Have you noticed that over time your metal halide setup seems to be getting dimmer and dimmer looking. First thing try new bulbs if it still seems dimmer im going to tell you to check your ballast. If its electronic ballast there no help for you sorry. But if its the old type which are heavy and has the coil type ballast there may be some relief. Most of the times if the light is still working its not the coil or the ballast in general that has gone bad but the capacitor which stores the charge to get the bulb going and to maintain the brightness. If the ballast hums, but nothing lights up, but does hum its still possible that you just have a bad capacitor. Heck if it hums you more than likely have a coil type ballast and not the electronic type. I will post pics later to show what im talking about. To check the capacitor we will have to pull the ballast apart. the capacitor is round usually and can possible hold a charge. Then we hook up a meter that can check Microfarad ratings. Most of them for this type of application will run about 15 up to 25 mfd. Most of them will be lower than the rating thus causing the lights to dim over time. The one i pulled apart tonight was completely dead 0uf reading. The ballast would hum but not lite the light. Changed the capacitor and walla working like a charm. This is not reccomend for anyone that does not now what they are doing. LIKE I SAID THEY WILL HOLD A CHARGE. Last thing I want to do is get someone shocked. Purely informational. Here is a link that shows what it looks like and as far as overdiving the lights not reccomended and i will not help do this due to saftey reason or issues. Your on your own lol. But is good info.

tquick
09/18/2008, 10:42 PM
ok some pics so you can see what im talking about.
Pic 1. Picture of the Pfo
Pic 2. Picture with the new capacitor in.
Pic 3. Close up of new cap.
pic 4. Reading of a good cap. Could be higher. Its rated for 15uf only getting 13.9. To get one close to 15 would brighten the lumen output. THe other side capacitor reads 0 and wont work. New capacitor in both sides and guess what just like new
pic 5. The reading on the bad Capacitor.
Pic 6. THe one thats being chucked into the trash.
pic 7. Electronic ballast see the size diffrence much smaller.
This is a duel PFO 250w ballast. THats why there is 2 capacitor and 2 coils
http://members.cox.net/tquick17/pictures/IMG_1226.JPG http://members.cox.net/tquick17/pictures/IMG_1232.JPG http://members.cox.net/tquick17/pictures/IMG_1233.JPG http://members.cox.net/tquick17/pictures/IMG_1236.JPG http://members.cox.net/tquick17/pictures/IMG_1231.JPG http://members.cox.net/tquick17/pictures/IMG_1230.JPG http://members.cox.net/tquick17/pictures/IMG_1227.JPG

tquick
09/18/2008, 10:47 PM
Ok the next ballast i have to show is one that has very dim output. 250 watts looks like a 60 watt bulb . Heres some pics of the ballast. Out of capacitors for now will have to order some more.
pic 1. The ballast
pic 2. The inside with a reading on the capacitor of 6.88 mfd
pic 3. The capacitor close up its the white cylindrical looking thing. Guess what its rated 15 mfd.

So i would love to bet you if i and when i get a capacitor in that it will be as bright as it should be
Need to order some. Both of these ballast had 15 mfd capacitor in them. Im going to assume that the higher 400 watt ballast will have even larger capacitors in them.
http://members.cox.net/hotdeals/IMG_1242.JPG http://members.cox.net/hotdeals/IMG_1239.JPG http://members.cox.net/hotdeals/IMG_1237.JPG

miwoodar
09/19/2008, 10:23 AM
Hey tquick - is this something we should add to our maintenance routine? How often should these be replaced?

gordon2726
09/19/2008, 10:32 AM
where can I buy ballast parts online? I think I need to replace my 70w sunpod's capacitor... It start to look very dim and make everything look yellowish... Thanks.

rdelong
09/19/2008, 02:06 PM
I know Hellolights sells replacement capacitors for many different types of ballasts but I'm no sure about 70W ballasts.

tquick
09/19/2008, 04:03 PM
I get mine from work since i do hvac i an abudnace of them. But if i didnt the best place would probally be ebay or a electric mortor supply place of some sort. once you open your unit see what size it is look for something like 15 mfd , 20 mfd or so one then look for the voltage can be like 330 vac, 440 vac. Try and get the same size capacitor alway if its a 15 mfd get a 15 mfd. Now for the vac thats a diffrent story if you have a 440 you cant use a 330vac. But if you have a 330 you can use a 440vac. You can alway go higher on vac but not lower hope this helps. normal price for a cap shipped is anywhere from 10 -25.