Metal Halide question?

[Rader Rods]

Ok, any electricians out there? I just purchased a pallet of used 400w low bays, while sorting them all out and testing I ran across one that is 277v. I can't see that it is a multi tap. The others have all been setup for 110v and all have worked. Is there a way to make it work on 110v?

 

[AGBill]

If you have carefully read the info plate on the ballast (transformer) and it indicates that it is only a single voltage (277V), then an alternative is to buy a new ballast form a local electial supplier that has a 120V tap.

You may want to contact the person you purchased the used fixtures from and see if he has a used 120V ballast laying around, it will be cheaper than a new one...

I also received my pallet of used 320W metal halide fixtures off of e-bay this week, and am evaluating what I have...

Good Luck.

 

[Jay H 237]

Ok, any electricians out there? I just purchased a pallet of used 400w low bays, while sorting them all out and testing I ran across one that is 277v. I can't see that it is a multi tap. The others have all been setup for 110v and all have worked. Is there a way to make it work on 110v?

Not without buying a transformer in which case you'd be better getting another ballast.

That 277v ballast was used on a single leg of 480v 3 phase.

 

[Rader Rods]

I am so confused on these lights, guess I need to learn how they work. Here is what I have. What bulb do I need to use with these? Looks to be wired for 110v!

 

[rockwithjason]

It is possible to run them on 240v but the lamps don't last long that way. You need a new ballast or a new fixture.

 

[Charles (in GA)]

The placard should tell you what bulb to use, such as a M59. Be very careful to get the correct bulb, some bulbs MUST be operated fully encolsed, others can operate in the open, If you use a fully enclosed bulb in an open fixture, you run risks of injury from the bulb, bad sunburn or injury if it fails (burns).

Charles

 

[Rader Rods]

It does say M59/H33 on it, but is that before they were converted to 110v or is the bulb the same for all voltages?

 

[Charles (in GA)]

It does say M59/H33 on it, but is that before they were converted to 110v or is the bulb the same for all voltages?

They were not "converted" to 120v, they were made that way if that is what is on the placard. Metal Halide, Sodium, and Mercury vapor lights are high voltage bulbs, that use a transformer (the ballast in the heavy housing) to take a given input voltage, and convert it to what the bulb needs to burn. Some ballast are multi-tap, meaning they have one common wire (marked as such) and several different hot or input wires, all marked with the input voltage for that wire, usually little flags attached to the wires, possibly imprinted on the wire itself. On a multi-tap, you merely select the voltage input you want to use, and connect it, leaving the other input wires capped off, unused. Multi-tap ballast cost more, they have more windings in them, the additional taps, and while more useful, especially in inventoring for spare or replacement parts, are not very good for initial installations, where a dollar saved on each ballast adds up when you are doing a whole manufacturing plant or Wal-mart store.

I recently bought 13ea 400w/120v MH fixtures. I was told they came from a Sams Club store, and was a little surprised to see they were 120v, I would have expected 277v fixtures in such an installation. I really wanted multi-tap or 240v capability, but will install these on a switched multi-wire "edison" circuit (two opposing 120v legs from the transformer and a shared neutral, with the lights on a hot and a neutral, evenly distributed on the two hots).

I consider myself lucky enough to have been able to buy something I could actually use. (either 120v or 240v).

If you didn't get lamps with these, I hope you didn't pay too much, the lamps are expensive, $30 or so apiece. I bought 13 complete fixtures and was given 19 lamps in case one or two were bad, everything worked, all for $520 cash and carry.

Charles

 

[W-Cummins]

It does say M59/H33 on it, but is that before they were converted to 110v or is the bulb the same for all voltages?

The bulb dose not care about the line voltage as it's kicked up by the transformer in the balast. Open up the case and see if there are multi taps on the transformer, if not it's only going to run on 277V. Some are setup for the multi taps and not listed that way (that way the manufacture only has to make one balast for all Vlotages, and just lable it as needed) 277v looks like 120v other than the plug should be diffrent. One hot, one grounded conductor, and an equipment ground, so it looks like 120v from the wiring.

It's not worth changing the balast in the lights as I'm sure that the new balasts cost more than you paied for the whole lamps.


William.....

 

[kbs2244]

I just learned something. An "Edison Circuit." I have wired the convience outlets of a few garages that way. Two hots and a single nutural. I use twin duplex 4x4 boxs with a white and tan outlet per box. The red leg always goes to the white and the black to the tan. Nutrals tied together.
My idea was always that if you are in the middle of something and pop a curcuit breaker, you can go over to the 4x4, plug into the other side and finish uo before having to go to the breaker box and re-set.
I can't remember where I learned it, or even if I came up with it myself, but since an inspector has never called me on it, I keep doing it.

 

[Rader Rods]

After the frustrations tonight I took one apart, and behold a multi-tap, with all the other "legs" capped off except the 110 that is hooked to the lead to the outside. So with that figured out just one more question about these things...other than the reflectors what is the diff between a high bay and a low bay?

 

[Charles (in GA)]

Light dispersal. High bay lights have a very high component of vertical light, very little horizontal. they are designed to get the light from a fixture anywhere from 20 to 90 ft high, down to the floor, High bay lights are very poor lighting below about 20 ft, as they have lots of dark spots and don't fill out the areas between the lights very well. Low bay lights are designed to disperse the light in a horizontal direction with very little vertical component, generally they are in-effective above 20 ft. but eliminate dark spots and gaps in lighting between the fixtures.

Charles

 

[Rader Rods]

Thanks Charles, but is the dispersal due to the reflectors? The basic light fixture w/out the reflectors is the same? I have 2 high bay lights and the only difference I see is the reflector, can a high bay use a low bay reflector and become a low bay?

 

[W-Cummins]

Thanks Charles, but is the dispersal due to the reflectors? The basic light fixture w/out the reflectors is the same? I have 2 high bay lights and the only difference I see is the reflector, can a high bay use a low bay reflector and become a low bay?

Yes the reflector and it's mounting location are the only changes the other parts are normally the same.

Glad to hear that they are multi tap lots of them are...

William..

 

[Charles (in GA)]

I just learned something. An "Edison Circuit." I have wired the convience outlets of a few garages that way. Two hots and a single nutural. I use twin duplex 4x4 boxs with a white and tan outlet per box. The red leg always goes to the white and the black to the tan. Nutrals tied together.
My idea was always that if you are in the middle of something and pop a curcuit breaker, you can go over to the 4x4, plug into the other side and finish uo before having to go to the breaker box and re-set.
I can't remember where I learned it, or even if I came up with it myself, but since an inspector has never called me on it, I keep doing it.

Some warnings and cautions about Edison Multi-wire circuits. First off, you are sharing the neutral. When you do this, the two hots MUST be from opposing sides (electrically) of the panelboard, if you take a meter and read across the two hots, you will read 240v. If you read across the two hots and see zero volts, then you have both hots powered by the same side (electrically) of the panelboard and you CANNOT share the neutral when you do this, it will be overloaded.

The two power sources, ie. the two hots, must be powered by either a double pole circuit breaker (the type used in 240v circuits) or two individual breakers that are joined with a handle tie. You must have a common trip of BOTH/ALL hot circuits. When one breaker trips, it must also trip the other breaker. {ref NEC 210.4(B)} Thus, by having one trip and you just plug into the other receptacle to keep working tells me you have a code violation, they both should have tripped........ or if they were both on the same side (electrically) of the panelboard then you could not share the neutral, or you would have a code violation there also.

Also, the neutral must be connected so that the removal of any one receptacle from the circuit for any reason, would not interrupt the neutral circuit, Thus you would need to wirenut the neutrals together in the box and provide a pigtail from the wirenut to the receptacle. {ref NEC 300.13(B)}.

If you really want to get funny about this, in a garage or certain other grade level areas, you are required to have the receptacles protected by GFCI protection devices. Either you would have to use individual GFCI receptacles (possibly very expensive) or you would have to use a double pole GFCI circuit breaker with common trip, also very expensive and possibly difficult to obtain in 15 or 20 amp ratings. This alone make this type of circuit not feasable for most applications. I will be using it for a dedicated lighting circuits in what is considered an inaccessable location (the ceiling) and GFCI is not required.

Charles

 

[Charles (in GA)]

After the frustrations tonight I took one apart, and behold a multi-tap, with all the other "legs" capped off except the 110 that is hooked to the lead to the outside

Took one of my ballast and opened up the housing. Did not find any additional taps, just the one marked for the 120V

I have identical ballasts, same brand, part number, etc, but made in two different places. I looked at one of the Mexican made ones, When I get a chance I'll have to look at or open up one of the USA (Illinois) made ones. All are identical Lithonia Luminaries.

Also, mine are marked on the side of the ballast housing, with approved and suitable reflectors (both high and low bay) that can be used with the ballast, and also the max ambient temp allowed with each reflector. Some of the metal reflectors can run at higher temps than the acrylic reflectors.

Go to the website for whatever brand you have and do a little research, you will be able to find other reflectors that are approved, but it might cost more than its worth to convert them, you may have to use them as is.

Charles