# Wall Packs



## geo5509 (Mar 9, 2010)

Went on a service call today. 3 out of 5 175w MH multi-tap wall packs not working. 1 was a melted ballast. The second one the cap. had exploded and the third one is the one giving me a fit. The line voltage is 120v. The voltage reading at the lamp socket was 277v. I checked the other 2 fixtures that were working and I got the same readings. I changed the lamp with one that was good and its not coming on. BTW these are 15yo Hubble fixtures.

So my question is why am I getting 277v at socket with only 120 coming in? And why is the lamp not burning when I have power at the lamp holder? Its been a really long day/week, any insight would be greatly appreciated.


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## 480sparky (Sep 20, 2007)

geo5509 said:


> ............So my question is why am I getting 277v at socket with only 120 coming in? ......



It's that goofy thing called a ballast. It's another term for a transformer.

Your open voltage is within specs (275-355 volts).

Click here for a nice TSing guide (starts on page 28)


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## geo5509 (Mar 9, 2010)

Thanks 480, I was assuming the ballast was stepping the voltage up. But what gets me is why the lamp is not working. I even tried to bend the contactor in the lamp holder up a little bit thinking it may not be getting a good connection with the lamp base. No Luck! 

Would I still be getting voltage in the lamp holder if the capacitor was bad? I wouldnt think so but I'am out of ideas.


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## geo5509 (Mar 9, 2010)

Oh and thanks for the link. Very helpful!!!


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## Roger123 (Sep 23, 2007)

Where are you taking your voltage reading from? The hot in the socket to ground or to the socket neutral?


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## nitro71 (Sep 17, 2009)

If it's not a warranty call I'd just replace the whole fixture..


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## Greg (Aug 1, 2007)

It could be a bad cap. I always replace the ballast and cap. (Company policy) You can get power at the socket but with a bad cap the bulb still won't fire.


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## stars13bars2 (Jun 1, 2009)

nitro71 said:


> If it's not a warranty call I'd just replace the whole fixture..


A warranty call on 15 year old fixtures? Your warranty is better than mine!


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## 480sparky (Sep 20, 2007)

Greg said:


> It could be a bad cap. I always replace the ballast and cap. (Company policy) You can get power at the socket but with a bad cap the bulb still won't fire.



If it takes anything more than a 12' stepladder to reach, I replace _everything_...... ballast, capacitor, ignitor, lamp, the whole shebang.


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## nitro71 (Sep 17, 2009)

I'm just saying in general if it's not warranty work I'll just swap the whole thing out instead of wasting time hunting down parts and swapping out pieces.


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## geo5509 (Mar 9, 2010)

Where are you taking your voltage reading from? The hot in the socket to ground or to the socket neutral?

Took reading from the hot in socket to ground.

It could be a bad cap. I always replace the ballast and cap. (Company policy) You can get power at the socket but with a bad cap the bulb still won't fire.

Thanks Greg, thats the answer I was looking for.

If it's not a warranty call I'd just replace the whole fixture.. 

agreed, thats what I wanted to do, but the owners didnt want mix matched fixtures on their building and at first they didnt want to replace all the fixtures but I talked them into it finally!


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## crazyboy (Nov 8, 2008)

Put lamp in, if it doesn't work replace the whole shebang ballast, cap, ignitor etc.


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## The Lightman (Jan 9, 2010)

If you don't have a lamp tester, swap out the lamp with one of the working ones. Out of the case, I get many lamps that are no good and I use 90% Sylvania.


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## geo5509 (Mar 9, 2010)

The Lightman said:


> If you don't have a lamp tester, swap out the lamp with one of the working ones. Out of the case, I get many lamps that are no good and I use 90% Sylvania.


That was the first thing I did.


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## The Lightman (Jan 9, 2010)

well, 480 confirmed the ballast is operating as designed, that leaves the capacitor and lamp holder.


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## geo5509 (Mar 9, 2010)

The Lightman said:


> well, 480 confirmed the ballast is operating as designed, that leaves the capacitor and lamp holder.


yeah, Im leaning towards the Cap. Iam replacing all the fixtures with new ones. After I replace them I'm going to swap Caps just to see if that was it.


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## 480sparky (Sep 20, 2007)

When it comes to HIDs, it's far more cost effective to just replace everything than spend the labor to troubleshoot an individual component. Unless it's something obvious, like a melted cap or smoked ballast.

But either way, gut it and replace it all.


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## MDShunk (Jan 7, 2007)

I recently gutted 3 wallpacks and put in 65w CFL's. So far, so good.


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## Roger123 (Sep 23, 2007)

Greg said:


> You can get power at the socket but with a bad cap the bulb still won't fire.


Hm, I am wondering how, after the OP wrote he had proper voltage at the socket?


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## Greg (Aug 1, 2007)

Roger123 said:


> Hm, I am wondering how, after the OP wrote he had proper voltage at the socket?


When the Capacitor discharges it give the lamp the necessary "kick" to start the chemical reaction, the ballast just maintains the reaction. You will still read ballast voltage even when the capacitor is shorted. A capacitance meter will tell you if the capacitor is bad, or a HID tester screwed into the socket will tell you whether it is the cap or ballast or both. I see it all the time, I don't waste my time troubleshooting HID lighting if the bulb doesn't fire, I change the bulb and ballast and capacitor. I only change the socket if the leads look worn/damaged or it is cracked.


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## Roger123 (Sep 23, 2007)

Greg said:


> When the Capacitor discharges it give the lamp the necessary "kick" to start the chemical reaction, the ballast just maintains the reaction. You will still read ballast voltage even when the capacitor is shorted. A capacitance meter will tell you if the capacitor is bad, or a HID tester screwed into the socket will tell you whether it is the cap or ballast or both. I see it all the time, I don't waste my time troubleshooting HID lighting if the bulb doesn't fire, I change the bulb and ballast and capacitor. I only change the socket if the leads look worn/damaged or it is cracked.


Thanks for the good info!


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## kwired (Dec 20, 2009)

crazyboy said:


> Put lamp in, if it doesn't work replace the whole shebang ballast, cap, ignitor etc.


I assume you check for voltage first


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## The Lightman (Jan 9, 2010)

Approximately six years ago, ballast manufacturers switched from standard oil filled metal capacitors to dry, plastic caps. Every day I replace melted or blown out plastic caps with metal. I keep six each of four sizes (10uf, 15uf, 24uf 400 & 480V) on my bucket truck. If I replaced the "whole shebang", I would be ripping my customers off by throwing away an operating core and coil ballast.


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## crazyboy (Nov 8, 2008)

kwired said:


> I assume you check for voltage first


Indeed....


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## 480sparky (Sep 20, 2007)

The Lightman said:


> .......... If I replaced the "whole shebang", I would be ripping my customers off by throwing away an operating core and coil ballast.


How are you ripping the customer off? If it takes you an hour of labor to troubleshoot an individual component to replace, then that could be considered ripping the customer off. It's cheaper (in the combination of material and labor) to replace everything and know with confidence that the light will function for another year or so. If you replace just one component, are you going to have that same level of confidence?

Besides, your customer wants the light not only to work, but they expect it to work for some time. How does it look if you tell them, "Yea, I found a bad ballast, so I replaced it.... you're good to go!" and two weeks later the capacitor gives out? Are you going to 'rip the customer off' and charge them another service call to change out the cap, or do you rip yourself off and consider it warranty work?


Now that you've changed the ballast and cap, in another three weeks the lamp goes out...............


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## The Lightman (Jan 9, 2010)

How are you ripping the customer off?-If I can repair a 400W MH light for material cost of $35.00 for a capacitor instead of throwing away an operating as designed iron core and copper coil ballast and capacitor for $114.00. I just saved the customer $79.00. I never replace the ballast without the cap that is included in the box.
98% of the work that I do is for contracted monthly lighting maintenance. One of "my" properties has over 400 HID fixtures. If I replaced the fixture or the whole shebang every time an arc tube failed to fully ignite, I probably wouldn't be invited back next month. 
All of my customers know with confidence that when I depart the property, every light is working, every month.
I absolutely understand that if there is some serious travel time, if your renting a lift or for many other reasons, a full lamp and ballast kit replacement is in order.


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## RIVETER (Sep 26, 2009)

Roger123 said:


> Hm, I am wondering how, after the OP wrote he had proper voltage at the socket?


I almost hate to bring it up but the capacitor is there for power factor correction. A tester that may be used if you can get it is Hubbel SCT #1. However it has a mogule base.


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## The Lightman (Jan 9, 2010)

*HID Lighting Troubleshooting Guide*

http://www.hydroponics.net/productdocs/HID_Pocket_Guide.pdf


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## 480sparky (Sep 20, 2007)

The Lightman said:


> How are you ripping the customer off?-..........


I'm not ripping anyone off. I repair the light, and it works for the *next 2-3 years with no problems*. If you have to take 3 trips up every year for the same light, I'd say _that_'s wasting the customers' money.


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## Innovative (Jan 26, 2010)

480sparky said:


> I'm not ripping anyone off. I repair the light, and it works for the *next 2-3 years with no problems*. If you have to take 3 trips up every year for the same light, I'd say _that_'s wasting the customers' money.


So, if you take your car in for service, they should just change or rebuild the whole engine. This way there are no problems with it for the next several years............
Normally I find that a ballast will last thru at least 2 or 3 capacitors before it goes bad. We only charge 21.00 for the cap and 88 for the ballast kit and still make a pretty penny.........


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## 480sparky (Sep 20, 2007)

Innovative said:


> So, if you take your car in for service, they should just change or rebuild the whole engine. This way there are no problems with it for the next several years............
> Normally I find that a ballast will last thru at least 2 or 3 capacitors before it goes bad. We only charge 21.00 for the cap and 88 for the ballast kit and still make a pretty penny.........


I don't spend a c-note just to get my car 40 feet in the air, either.


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