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Posted By: PAUL0510 HID Lighting - 07/24/04 03:38 PM
I have a question about outside flood lights. I was wondering how to trouble shoot HID lights. I had one that was shorting out a circuit. All the wires inside the fixture looked fine. Could it be the cap. or starter? Maybe the trans. It is a hubbell(mhs--0400s-268-pcr)with a GE LU400 lamp. What do the numbers and letters stand for exactly? Ive changed out the light with a new one but it is not the same. it is a hubbell (mhs-y400h-468-1) it came with a 400w mvr400/u GE lamp. I thought it would come with a metal halide lamp. Can you replace a mercury vapor with a metal halide? or vice versa? All of the other lights have a LU400 GE lamps. The outside of the building looks ugly with diferent types of lamps.
Any help is greatly appriciated.

Great site keep up the good work.
Posted By: Tom Re: HID Lighting - 07/24/04 10:08 PM
Visit to determine what those Hubbell numbers mean.

I think GE calls their Metal Halide lamps "MultiVapor" which could account for the MVR in the catalog number, the 400 is the wattage & the "U" is for universal position.

If you can lay your hands on a Lithonia catalog, they have a troubleshooting guide in the back.. Or, go to and download their "Pocket Guide to High Intensity Discharge Lamps and Ballasts" which also includes a troubleshooting section.

Posted By: caselec Re: HID Lighting - 07/24/04 11:38 PM
Your original flood light is designed for 400 watt high pressure sodium lamps. The floodlight you replaced it with is for 400 watt metal halide lamps. You can not interchange the two lamps. You will need to replace the ballast or order a new floodlight. The “S” after the wattage in the mhs-0400s-268 catalog number stands for high pressure sodium. “H” is for metal halide and “P” is for pulse start metal halide.

Posted By: uksparky Re: HID Lighting - 07/25/04 12:35 PM
Can a lamp of the same wattage be used with any ballast rated for that wattage, such as, a 400 W Metal Halide lamp with a 400 W High Pressure Sodium ballast?
No. A lamp will only operate properly when used with the ballast designed for that particular lamp. The lamps to be used with a particular ballast are listed on the ballast label and in the ballast literature. Lamp and ballast compatibility is assured by matching the American National Standards Institute (ANSI) designations for both the lamp and the ballast. Using a lamp that is not specified will affect ballast life, lamp life or both. HID lamps all have specified unique operating characteristics. The ballasts have been designed to operate the lamps within those specified parameters.


Just spotted it.

[This message has been edited by uksparky (edited 07-25-2004).]
Posted By: CRM Re: HID Lighting - 07/25/04 04:54 PM
Although you can use a mercury vapour bulb with a metal halide ballast, but you can't use a metal halide bulb in a mercury vapour ballast.
Posted By: frenchelectrican Re: HID Lighting - 07/26/04 01:35 AM
CRM: that is correct because the ballast open circuit voltage is diffent between the mercury vapour and metal haldie bulb.

Paul ,, i will suggest to recheck the ballast to see what the label it say what type of lamp it required to use if say 'M-51" or S-51 please watch out the ballast destaion number you can not interchange both bulbs at all otherwise you will damged the running gears.

merci , marc
Posted By: PAUL0510 Re: HID Lighting - 07/26/04 06:52 PM
Thanks for the info. I was able to talk the owner into getting some new fixtures. $$$$ Thanks again.
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