metal halide wattage question have 175 w fixture, can i use less wattage bulb?

hi folks, i have a fixture thats rated for a 175 watt metal halide
bulb, but i am wondering if i may place a metal halide bulb of less
wattage in it, it seems that that would be ok, as long as i didnot go
in the other direction, say installing a higher wattage bulb. it uses
a mogul base, and i have seen 70 watt and 100 and 150 watt bulbs, i
wonder if they will not harm the ballast or themselves,

thanks
jack

Absolutely not!

The ballast is designed to deliver a voltage and current for that wattage of
bulb. You can damage the bulb and/or the ballast.
John

"john private smith" <> wrote in message
news: om...
> hi folks, i have a fixture thats rated for a 175 watt metal halide
> bulb, but i am wondering if i may place a metal halide bulb of less
> wattage in it, it seems that that would be ok, as long as i didnot go
> in the other direction, say installing a higher wattage bulb. it uses
> a mogul base, and i have seen 70 watt and 100 and 150 watt bulbs, i
> wonder if they will not harm the ballast or themselves,
>
> thanks
> jack

If you use a lower rated bulb it will light. Then it will shut off when it
overheats, then it will re light again, and restart the cycle... after a
while it will burn out the ballast and the bulb more than likely, I never
let one run that way for long enough to see first hand.

Once had an apprentice replace a burned out 175w MH in the warehouse with a
150 watt bulb, it was funny to watch him try to figure out what was wrong.
I don't know where the 150w came from, as I had only 175 and 250 fixtures
in there.

Steve Sells
IBEW 305 Electrician, and fish nut


"john private smith" <> wrote in message
news: om...
> hi folks, i have a fixture thats rated for a 175 watt metal halide
> bulb, but i am wondering if i may place a metal halide bulb of less
> wattage in it, it seems that that would be ok, as long as i didnot go
> in the other direction, say installing a higher wattage bulb. it uses
> a mogul base, and i have seen 70 watt and 100 and 150 watt bulbs, i
> wonder if they will not harm the ballast or themselves,
>
> thanks
> jack

On Sun, 16 Nov 2003 02:45:01 GMT, "Steve Sells" <>
wrote:

>If you use a lower rated bulb it will light. Then it will shut off when it
>overheats, then it will re light again, and restart the cycle... after a
>while it will burn out the ballast and the bulb more than likely, I never
>let one run that way for long enough to see first hand.

Using a MH lamp that is rated for less power than the ballast can lead
to lamp explosion, fire and perhaps personal injury. DO NOT DO THIS.

--
Vic Roberts
http://www.RobertsResearchInc.com

On 15 Nov 2003 16:47:13 -0800, (john
private smith) wrote:

>hi folks, i have a fixture thats rated for a 175 watt metal halide
>bulb, but i am wondering if i may place a metal halide bulb of less
>wattage in it, it seems that that would be ok, as long as i didnot go
>in the other direction, say installing a higher wattage bulb. it uses
>a mogul base, and i have seen 70 watt and 100 and 150 watt bulbs, i
>wonder if they will not harm the ballast or themselves,

DO NOT use a lower rated metal halide lamp with your 175 watt metal
halide ballast. The ballast will try to push the rated current for a
175 watt MH lamp through the lower rated lamp and, in most cases, will
overheat the lamp and cause it to explode!

--
Vic Roberts
http://www.RobertsResearchInc.com

On Sun, 16 Nov 2003 03:44:09 GMT, Victor Roberts
<> wrote:

>On 15 Nov 2003 16:47:13 -0800, (john
>private smith) wrote:
>
>>hi folks, i have a fixture thats rated for a 175 watt metal halide
>>bulb, but i am wondering if i may place a metal halide bulb of less
>>wattage in it, it seems that that would be ok, as long as i didnot go
>>in the other direction, say installing a higher wattage bulb. it uses
>>a mogul base, and i have seen 70 watt and 100 and 150 watt bulbs, i
>>wonder if they will not harm the ballast or themselves,
>
>DO NOT use a lower rated metal halide lamp with your 175 watt metal
>halide ballast. The ballast will try to push the rated current for a
>175 watt MH lamp through the lower rated lamp and, in most cases, will
>overheat the lamp and cause it to explode!

Here is some data on the rated current and voltage of a few MH lamps.

Lamp Rated Current Nominal Voltage
175-watt MH 1.5 Amps 132 Volts
100-watt MH 1.1 Amps 100 Volts
70-watt MH 0.9 Amps 85 Volts

Pushing 1.5 Amps through a 100-watt or 70-watt MH lamp will cause
serious overheating.

--
Vic Roberts
http://www.RobertsResearchInc.com

Come on people... can you say troll?

Gotcha!!!

"Victor Roberts" <> wrote in message
news:...
On Sun, 16 Nov 2003 03:44:09 GMT, Victor Roberts
<> wrote:

>On 15 Nov 2003 16:47:13 -0800, (john
>private smith) wrote:
>
>>hi folks, i have a fixture thats rated for a 175 watt metal halide
>>bulb, but i am wondering if i may place a metal halide bulb of less
>>wattage in it, it seems that that would be ok, as long as i didnot go
>>in the other direction, say installing a higher wattage bulb. it uses
>>a mogul base, and i have seen 70 watt and 100 and 150 watt bulbs, i
>>wonder if they will not harm the ballast or themselves,
>
>DO NOT use a lower rated metal halide lamp with your 175 watt metal
>halide ballast. The ballast will try to push the rated current for a
>175 watt MH lamp through the lower rated lamp and, in most cases, will
>overheat the lamp and cause it to explode!

Here is some data on the rated current and voltage of a few MH lamps.

Lamp Rated Current Nominal Voltage
175-watt MH 1.5 Amps 132 Volts
100-watt MH 1.1 Amps 100 Volts
70-watt MH 0.9 Amps 85 Volts

Pushing 1.5 Amps through a 100-watt or 70-watt MH lamp will cause
serious overheating.

--
Vic Roberts
http://www.RobertsResearchInc.com

WOW GUYS THANKS FOR THE EDUCATION!
i can tell its a bad idea, and i understand why.
thanks for all your help, i will be replacing the bulb with the same!

BTW (by the way) what is "TROLL"?

thanks
jack

> BTW (by the way) what is "TROLL"?
>
> thanks
> jack

A troll is someone who comes in to a messageboard or newsgroup with the sole
intention of causing trouble. Some trolls make a racist comment and then sit
back and watch a massive row break out amongst the regular members of the
group