# HID Help Please!



## McClary’s Electrical (Feb 21, 2009)

GEORGE D said:


> Have a MH 175 watt fixture I replaced ballast in a couple weeks ago, now customer says it went out, they put in new bulb, still no light. I put in new bulb and it acts like it wants to start but never gets bright and cuts off. Transformer open output is 320 v which is correct. Checked CAP with MM and it appears fine. Any suggestions please!


 
Describe your procedure of checking the cap


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## kaboler (Dec 1, 2010)

Could be the bulb, but 90% of the responses here will be to replace the transformer and be done with it. Troubleshooting beyond what you've done would be pretty hard. Testing the cap is beyond what most people'd do.

I've had a bad bulb once.

Check line voltage too. Is 320v a bit high for MH?


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## GEORGE D (Apr 2, 2009)

Surely not the best way but with a MM ohm test. Shorted cap leads, then ohmed between the to. Numbers started high and slowly went low, have extra good ones and checked those which gave same characteristics.


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## McClary’s Electrical (Feb 21, 2009)

GEORGE D said:


> Surely not the best way but with a MM ohm test. Shorted cap leads, then ohmed between the to. Numbers started high and slowly went low, have extra good ones and checked those which gave same characteristics.


So you measured resistance, but didn't measure capacitance. Hard to say what you've really got.


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## 480sparky (Sep 20, 2007)

HID troubleshooting guide, starts around page 28 or 29.


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## Yukoner (Apr 7, 2012)

check to make sure that all of the leads from the ballast are insulated properly from the primary side of the tri tap, if thats what the ballast is. ive ran into that problem before where one of the marrettes fell of and periodically was shorting out on the casing.


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## sbrn33 (Mar 15, 2007)

Almost guarantee its a bad cap. replace the cap and you will be good.


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## 10492 (Jan 4, 2010)

Bulb and ballast match?

If this was a Pulse start, you'd have a starter....


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## sbrn33 (Mar 15, 2007)

175 pulse start???


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## GEORGE D (Apr 2, 2009)

Replaced everything so now it works of course. This really sucks because its a warranty job that's 1.5 hrs away. If someone hit the fixture with a box during operation, could that cause bulb and possibly xfirmer or cap to go bad?


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## 10492 (Jan 4, 2010)

sbrn33 said:


> 175 pulse start???


No...they don't make them?

Can't say I've ever seen one, in the 175W variety....but that ain't saying much.......


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## kaboler (Dec 1, 2010)

GEORGE D said:


> Replaced everything so now it works of course. This really sucks because its a warranty job that's 1.5 hrs away. If someone hit the fixture with a box during operation, could that cause bulb and possibly xfirmer or cap to go bad?


Ouch buddy! But at least the customer's happy.


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## frenchelectrican (Mar 15, 2007)

sbrn33 said:


> 175 pulse start???


I have see couple over French side but it kinda little rare for pulse start 175 MH but probe start yeah that is run of mill item ( for mogual base socket bulbs but medium based bulbs some will come in pulse start verison but you can ge them in probe start as well )

150 W MH in pulse start sure I have see few of them. ( once a while you may hit a oddball probe start verison )

GEORGE D.,

If you did snag the ANSI ballast number then use 480 Sparky's link to refer to the troubleshooting that will give you a pretty much excat answer ( it will varies a little so expect that )

And make sure the bulb and ballast are matched set also check the voltage to the luminiare to make sure they don't drop very much when the luminaires do kick in.

IIRC with CWA ( Constast Wattage Autotransfomer ) ballast the current drawage will be low when first start up and it will ramp up when the lamp is warming up 

But if you have Reactor ballast watch the supply voltage to make sure it is right on the specs. most of the MH ballast can withstand pretty good voltage drop before it will arc out ( drop out ) IIRC about 60% of line voltage.

Merci,
Marc


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