Changing HID wallpacks to CFLs

[chrisrappl]

I have a plant with a large number of Holophane WL2K175MHMBBZF2 175w Metal Halide wall pack fixtures operating on 208v single phase power. They are less than ten years old and appear to be in good condition overall. I have two concerns with the original installation that I would like to address. The fixtures require 150 deg C supply conductors and are fed with 90 deg C THHN conductors. Where the supply conductors were not carefully trained away from the reflector and/or ballast, the conductors have overheated and the insulation is now brittle or worse. The other concern is that there is no emergency lighting or instant restart lighting in the areas served by these wallpacks. My plan at this point is to modify the existing fixtures to accept a self-ballasted CFL lamp that should reduce the heat generated in the fixture and restart quickly when interrupted. The lighting circuits are protected by a standby generator, so they should be energized within about 10 secs of a power interruption.

I cannot find 208v self-ballasted CFL lamps. They seem to be available in 120v and 277v. I could pull a grounded conductor in place of one of the existing branch circuit conductors, but this will be quite involved and there may be other lighting on these circuits that I will not be converting. I could try to install a grounded conductor in addition to the existing conductors, but again this will be quite involved and may not be possible.

I looked at the multi-tap ballast in the existing fixtures to see if I could backfeed it with 208v and end up with 120v. The closest that I have come is to feed the lamp and common leads with 208v, connect the socket leads to the 277v and com leads and splice the capacitor leads together. This gives me a measured voltage at the socket of 114.8v using a 75w/ 130v test lamp. I don't think that the multitap ballast is just a transformer, because my socket voltage is drastically affected by the lamp load. With no load the socket voltage is 142.2v as opposed to 114.8v with the test lamp installed.

I priced a simple 208v to 120v transformer, but that would add almost $50 to the cost of each fixture and I'm looking at about 150 fixtures to start.

The CFLs that I'm looking at are Maxlight #11271 60w/120v. The factory tech support says that this is a good application for that lamp and that it will not overheat in the enclosed fixture.

If anyone has experience with this, I'm open to suggestions. Maybe I'm looking at this all wrong. Or maybe there is another option that I haven't considered.

I'd appreciate any help with this one.

 

[chrisrappl]

I spent some time with one of these fixtures this morning. This is what I have discovered:

The voltage at the lamp (as designed) measures 299.6v. With the capacitor bypassed, the voltage at the lamp measures 283.9v.

The multitap ballast is an inductor core autotransformer. It is designed to limit the current to a certain value which I don't believe the 60w CFL is exceeding because my voltage readings at the lamp are constant with or without the lamp load (283.9v with no lamp installed, 283.9v with lamp installed and lit). If I exceed the current limiting value of the inductor core, I should see a noticeable voltage drop which I am not seeing.

Right now I have a 277v 60w CFL installed and running. It appears to start and run properly.

I would like my lamp voltage to be as close to 277v as possible. I think a safe variance is probably around 5% which would place the high value at 290.85v. 283.9v is well within that range.

I need someone smarter than me to tell me why this won't work.

Thanks

 

[peter d]

I think it's silly that you're trying to reinvent the wheel.

 

[chrisrappl]

Fair enough. What would you recommend?

 

[jeremysterling]

Earlier in this past week, I had to explain to a restaurant manager that the low light output from his 150W HPS wallpacks was due to someone reengineering the fixture by removing the ANSI S55 ballast and fitting a 65W BR40 lamp. The plastic lenses were end-of-life (yellowed, broken) so I recommended replacing the wallpacks with equivalent fixtures. The customer may want T5 or LED or HID or whatever.

If restrike and high temp is your concern, wreck out the entire existing fixture and install LED or T5.

 

[chrisrappl]

My first recommendation was to replace the fixtures with LED fixtures.

One of the challenges is that we are working with repair and maintenance funds, not capital expense funds.

Hopefully in a few years they can budget for replacement fixtures.

Another challenge is that these fixtures are part of a Plasti-bond pvc coated rigid conduit system. Most of the fixtures are rigidly piped in place, some with conduits entering from the left, right and rear. Replacing the fixtures will probably require extensive repiping and then complete rewiring which I am trying to avoid at this time.

There are approximately 143 fixtures.

 

[hurk27]

you do realize that the amount of light output your going to get from a CFL is going to be drastically much lower then the light output of the 175 watt HID? I don't have the lumen's chart at hand right now but going from the 175 HID to a 60 watt CFL is like putting a candle in place of a 100 watt incandescent.

The transformers in a HID multi tap ballast are an auto-transformer type system, putting in 208 to the 208 tap and common will give you 120 volts between the 120 volt tap and common but this would also put the shell of the socket at 120 volts to ground which is a very dangerous situation too bad they weren't fed with 277v, but these transformers are not designed or listed to be used as such and even though you will not have the 175 watt lamp load they will draw much more current (wattage) then the expected savings you would normally get from the 60 watt CFL.

Personally before I would try to use a tap on the ballast to power these 120 volt CFL's I would re-identify one of the circuit conductors as a grounded conductor re connecting it to the neutral bar at the supply end and go from there, but being that both methods are against code since the circuit conductors are most likely smaller then the #6 awg that the code allows for re-identifying and the transformer is not UL listed as a transformer for other loads as well as the danger of having the shell at 120 volts to ground, nether option is a good idea from a liability stand point.

Myself I would tell them to spend the money to change the fixtures or leave it as it is, no way would I do something like this that could come back and bit me in a court of law if someone was to get hurt.

 

[chrisrappl]

Wayne,

That's good advice and I appreciate it. You are right about the inefficiency of utilizing the autotransformer; 190w with the transformer as opposed to 60w without. The loss would be 130 watts per fixture which is a deal breaker. The lumen difference is a big concern. I think I read that the mean lumens of the horizontal 175 was just under 10,000 lumens where the mean lumens of the 60w (actual, not equivalent) is just under 5,000. The customer has seen the fixture with the CFL installed and was OK with the light output. I think it will be too little, especially after a few hundred hours of operation.

This is interesting even if only to watch the fastest electrician I've ever seen:

http://www.youtube.com/watch?v=VomUoTpXL4k

 

[weressl]

Wayne,

That's good advice and I appreciate it. You are right about the inefficiency of utilizing the autotransformer; 190w with the transformer as opposed to 60w without. The loss would be 130 watts per fixture which is a deal breaker. The lumen difference is a big concern. I think I read that the mean lumens of the horizontal 175 was just under 10,000 lumens where the mean lumens of the 60w (actual, not equivalent) is just under 5,000. The customer has seen the fixture with the CFL installed and was OK with the light output. I think it will be too little, especially after a few hundred hours of operation.

This is interesting even if only to watch the fastest electrician I've ever seen:

http://www.youtube.com/watch?v=VomUoTpXL4k

Couple of other things to consider:
CFL's may have a problem with starting at low ambient teperatures and definetly have lower light output.
CFL's have shorter life than MH's.
Any non-approved retrofit would violate the listing of the fixture.
I won't be concerned about the hard-pipe retrofit. Just thread a cast box in the place of the fixture and cord-plug it.
LED's are still way the most expensive replacements and they are all over the world with performance.
Try to circle back and consider induction light replacement. Instant restrike, the lower the ambient the brighter they are, longest lasting, eg. lowest maintenance cost, low temperature, not thermal degradation of optics.

 

[growler]

Right now I have a 277v 60w CFL installed and running. It appears to start and run properly.

I would like my lamp voltage to be as close to 277v as possible.

If you are going to change these to CFL then why not get you some 230V CFLs out of the UK or maybe Canada and then up the wattage to 150 W.

That should produce more light than the 60 W and be closer to operating voltage and no transformer.

 

[rt66electric]

Change entire run to 120v????

Change entire run to 120v????

in most cases it is easy to change 208 to 120v, ( I know the neutral will not be white)
For an entire lighting run,
Strip out the ballasts and save them for other fixtures. redo one section at a time.

I have have had good luck putting CFL's in old fixtures

 

[barclayd]

My recommendation is to contact Holophane and see if they have retrofit kits.
You could change out a few at a time with your O&M dollars. If 'they' want them all done at once, additional funding will be required.
I would not even think about modifying the existing MH ballasts.
Talk to some lighting reps.
db

 

[gadfly56]

If you go to Holophane's web site they have LED wall packs with glass (up to 105w ~6,700 lumens) or plastic (up to 66w ~4400 lumens) lenses. Cap the exsiting box and hard pipe or cord-and-plug as Laszlo suggested. They'll run on 208. Not offering any opinion on service life or ROI.

 

[hurk27]

Wayne,

That's good advice and I appreciate it. You are right about the inefficiency of utilizing the autotransformer; 190w with the transformer as opposed to 60w without. The loss would be 130 watts per fixture which is a deal breaker. The lumen difference is a big concern. I think I read that the mean lumens of the horizontal 175 was just under 10,000 lumens where the mean lumens of the 60w (actual, not equivalent) is just under 5,000. The customer has seen the fixture with the CFL installed and was OK with the light output. I think it will be too little, especially after a few hundred hours of operation.

This is interesting even if only to watch the fastest electrician I've ever seen:

http://www.youtube.com/watch?v=VomUoTpXL4k

I was thinking you were talking about 60 watt equivalent (13 watt actual) type CFL's, not 60 watt actual CFL's, after seeing the lumen's it was clear which ones you were talking about, yes I have seen some replacement CFL's that are quite big and high in lumen's we use a 70 watt at work that is 277 volt and is quite bright, as well as some 120 volt ones at the 60 watt actual wattage that are quite bright, I hear there are actual 100 watt units out in Mogul base for 277 volts, not seen them yet?

 

[chrisrappl]

Laszlo recommended something I didn't even know about - induction lighting. A little research shows that they do in fact make self ballasted induction lamps. The science is interesting. They run cool, start quickly hot or cold and last a long time. Rule of thumb is to replace HID lamps with induction lamps at 1/2 the wattage for approximately the same lumens. They are pretty expensive, but their long life (up to 100,000 hours) should more than make up for the initial cost. If I could find a self-ballasted, 208v rated, 80w, E39 base lamp, I would be in business except for one big problem. Due to these fixtures being fed by 208, applying the feed voltage directly to the socket would result in the screw shell being energized at 120v which is not acceptable. It never occurred to me before, but this must be why self-ballasted lamps only seem to be available in 120v and 277v configurations. In each application, the screw shell would be connected to a grounded conductor.

 

[weressl]

Laszlo recommended something I didn't even know about - induction lighting. A little research shows that they do in fact make self ballasted induction lamps. The science is interesting. They run cool, start quickly hot or cold and last a long time. Rule of thumb is to replace HID lamps with induction lamps at 1/2 the wattage for approximately the same lumens. They are pretty expensive, but their long life (up to 100,000 hours) should more than make up for the initial cost. If I could find a self-ballasted, 208v rated, 80w, E39 base lamp, I would be in business except for one big problem. Due to these fixtures being fed by 208, applying the feed voltage directly to the socket would result in the screw shell being energized at 120v which is not acceptable. It never occurred to me before, but this must be why self-ballasted lamps only seem to be available in 120v and 277v configurations. In each application, the screw shell would be connected to a grounded conductor.

I just looked up at the lampholder on my floorstand, it's a metallic shell and it is stamped 250V.

http://www.mylampparts.com/Products/Bakelite-threaded-socket-with-ring-and-18-hickey__SL19192-B.aspx

 

[gadfly56]

Laszlo recommended something I didn't even know about - induction lighting. A little research shows that they do in fact make self ballasted induction lamps. The science is interesting. They run cool, start quickly hot or cold and last a long time. Rule of thumb is to replace HID lamps with induction lamps at 1/2 the wattage for approximately the same lumens. They are pretty expensive, but their long life (up to 100,000 hours) should more than make up for the initial cost. If I could find a self-ballasted, 208v rated, 80w, E39 base lamp, I would be in business except for one big problem. Due to these fixtures being fed by 208, applying the feed voltage directly to the socket would result in the screw shell being energized at 120v which is not acceptable. It never occurred to me before, but this must be why self-ballasted lamps only seem to be available in 120v and 277v configurations. In each application, the screw shell would be connected to a grounded conductor.

Is there an issue with LED's (besides cost)? Those Holophane has at 208V, as I pointed out above. Why reinvent the wheel?

 

[weressl]

Is there an issue with LED's (besides cost)? Those Holophane has at 208V, as I pointed out above. Why reinvent the wheel?

More intitial cost, shorter lasting, less light output, greater end-of-life light loss?

Who is re-inventing the wheel? Induction lights are around much longer than LEDs.

It is more like re-discovering technology that has been there, but never got the sex-appeal and hype LED's are gettting. Good technical poeple never fall forthose, only for the overlla technical merit.