ECN Forum

Mercury Vapor bulbs

Posted By: aldav53

Mercury Vapor bulbs - 01/18/06 03:28 PM

In some parking lot bulbs I'm replacing, will a 250 watt (M138) run in a 400 watt 277/480 volt mercury vapor fixture?
Posted By: mshaw

Re: Mercury Vapor bulbs - 01/18/06 04:04 PM

I do not think so. I believe that the ballast and the lamp are matched so only a 400 watt lamp will work.
Posted By: renosteinke

Re: Mercury Vapor bulbs - 01/18/06 04:22 PM

I'd advise against trying. While the bulb might fit in the socket, the igniter, capacitor, and ballast are all sized to the bulb. Having the wrong bulb in is likely to result in a very short life for the ballast.

While you're changing ballasts- why not upgrade to Metal Halide? MH bulbs do not decrese in brightness as they age, as mercury bulbs do, yet still give a clean white light.
Posted By: Old Town

Re: Mercury Vapor bulbs - 01/18/06 04:31 PM

About 3 years ago I relamped about 10 70W med. base HPS lamps. I was out at the same place a couple of months ago and I had to replace a ballast. Much to my suprise the ballast was 100W. Lamp and ballast life seem to be uneffected by this mismatch. But I would not reccomend it.


[This message has been edited by Old Town (edited 01-18-2006).]
Posted By: CTwireman

Re: Mercury Vapor bulbs - 01/18/06 05:10 PM

Quote
MH bulbs do not decrese in brightness as they age, as mercury bulbs do, yet still give a clean white light.


That's not true at all. All HID lighting sources have declining lumen output as they age. HPS has the best lumem maintenance, followed by MH and then MV.

The basic probe start MH lamps have poor lumen maintenance, especially as they near the end of their rated life. However, pulse start and the newer ceramic metal halide systems have pretty well conquered this problem.

Peter
Posted By: aldav53

Re: Mercury Vapor bulbs - 01/18/06 06:11 PM

mshaw, I think you might be right. Also, both sockets are the larger Mogal base type.
Posted By: aldav53

Re: Mercury Vapor bulbs - 01/18/06 06:15 PM

Also, it says 480 volt on the fixture, did not measure it but it must be 277 volt. Don't think those are 480 from socket to center. Gotta be 277v.
Posted By: mxslick

Re: Mercury Vapor bulbs - 01/18/06 08:08 PM

The voltage referrs only to the fixture's input voltage, not the voltage seen by the lamp. IIRC merc vapors operate at around 80 volts once the arc is struck.

And the 250 watt bulb in the 400 watt fixture is an extremely bad idea. If you're lucky all that will happen is the lamp won't light. Otherwise you could easily have bulbs exploding or ballasts going down in flames.

Either get the right bulbs or get rebuild kits that will have the bulb, ballast and any other essentials.
Posted By: Rewired

Re: Mercury Vapor bulbs - 01/18/06 10:24 PM

If you are going to change everything you might as well go to HPS if colour is not an issue.. I believe the "lumens per watt" is greater for HPS than metal halide or old school mercury...
Also, double check your input voltage.. I once put a ballast in a fixture that was labelled " 230V". and had a " 115 / 230V" dual rated ballast.. too bad for me the input WAS 600V!
it looked spectacular for about 6 seconds when everything was turned on! [Linked Image]
Posted By: renosteinke

Re: Mercury Vapor bulbs - 01/19/06 01:16 AM

Aldav, I admit I was surprised the first time I encountered it, but there ARE ballasts out there that take 480v...two 'hots'...for their input voltage.
I was working on such a system just last week.
Posted By: Old Town

Re: Mercury Vapor bulbs - 01/19/06 02:18 AM

Was this in the United States? I have never encountered 600V lighting. I have seen 480V lighting many times but never 600V. 480V outdoor lighting is very common here for HID high intensity applications. As high as copper is now I think you will be seeing it even more.
Thanks,
Ty

Sorry, I just read your profile......Canada Eh? That's where the 600V must have come from.


[This message has been edited by Old Town (edited 01-18-2006).]
Posted By: Trumpy

Re: Mercury Vapor bulbs - 01/19/06 10:10 AM

CTWireman,
Quote
That's not true at all. All HID lighting sources have declining lumen output as they age. HPS has the best lumem maintenance, followed by MH and then MV.

Peter,
Why is it that a lot of local authorities are stipulating Metal-Halide over HPS or any other such slack lighting source.
Metal Halide is good because MVA (Motor Vehicle Accident) incidents are less under MH than HPS or any sub-servient lighting source.
Scotty (lines Apprentice) and I changed out half of the lights in town here.
Took us 3 weeks, but the people like the colour change and the extra light.
Posted By: iwire

Re: Mercury Vapor bulbs - 01/19/06 10:37 AM

Quote
but there ARE ballasts out there that take 480v...two 'hots'...for their input voltage.


Very true, we install hundreds of them in parking lots, heck we would use 600 volt if that was available.

The high voltage keeps the costs of the raceways and conductors under control.

However as mxslick mentioned the input voltage is not the voltage at the socket.

Most newer ballasts have the socket voltage marked on them and it is a range.

It will say "OC voltage xxx"

For example a 400 MH ballast if I remember correctly has a open circuit voltage around 280 volts.

But to answer the opening question in general no you may not interchange lamps without changing the ballast.

There are a few lamps that interchange but look at the ballast and it will tell you what are the approved lamps.

I always order HID lamps and ballasts by the ANSI number.
Posted By: aldav53

Re: Mercury Vapor bulbs - 01/19/06 03:21 PM

I'll just be changing the bulbs, not transformers too, and will definitely stick with 400 watt.
MH, MV, & HPS should be interchangable as long as the wattage and voltages are correct, right? Just different light?
Posted By: hbiss

Re: Mercury Vapor bulbs - 01/19/06 05:21 PM

Nope! Each type of lamp requires a ballast designed for it. When you relamp a fixture you have to observe the correct wattage as well as the type of lamp.

-Hal
Posted By: renosteinke

Re: Mercury Vapor bulbs - 01/20/06 03:02 AM

Even though the bulb socket and wattage might be the same, the different types of bulbs have greatly different operating voltages a,d different ignition requirements. They're not at all like your usual light bulb.
Posted By: Rewired

Re: Mercury Vapor bulbs - 01/21/06 04:01 AM

Old Town: Ya eh, its a Canadian thing being 600V BUT thats very RARE now.. "347" is a common voltage for lighting supplied off a 600V supply ( Phase to neutral voltage)

Hbiss & Renosteinke:
Metal Halide ballasts are able to operate a mercury bulb of equal wattage, BUT not the other way around.. The O.C.V of metal halide is greater than mercury but operating characteristics are almost identical, very often ballasts are rated say " M59 OR H33" for example for a 400W lamp ( I think those are the correct ANSI numbers????

" Metal halide PULSE START" are a world of their own as well as HPS.. No means interchangeable with anything else..
A.D

[This message has been edited by Rewired (edited 01-20-2006).]
Posted By: CTwireman

Re: Mercury Vapor bulbs - 01/21/06 07:23 PM

Quote
Posted by Trumpy:

Peter,
Why is it that a lot of local authorities are stipulating Metal-Halide over HPS or any other such slack lighting source.


I don't know, but I know that's not the case in the United States. The vast majority of public roadway lighting is HPS here, with a lot of Mercury Vapor still in use.

The standard probe start metal halide lamp has a life of 10,000 to 15,000 hours. HPS is well over 24,000 with better lumen maintenance.

Futhermore, with the extremely high cost of maintaining thousands of street lights, the long life, high lumens-per-watt and passive failure mode of HPS give it clear advantages over MH.

Peter
Posted By: renosteinke

Re: Mercury Vapor bulbs - 01/21/06 10:31 PM

Trumpy, I cannot speak for anyone who specifies roadside lighting- but, personally, I simply can't abide the color of HPS lighting.

Much of the "increased lumen" output seems lost to my eyes, as color perception goes to pot. This is an even greater problem where HPS is used in a warehouse- where I have difficulty focusing and reading pallet markings under HPS light.

When HPS was adopted here, it was invariably installed in direct opposition to the howls of outrage from the populace. Specifiers loved it, however, because of the percieved economic benefits. Today, with MH, that argument just doesn't hunt anymore. MH gives the economics of HPS with a more natural color.
Posted By: JBD

Re: Mercury Vapor bulbs - 01/21/06 11:25 PM

Another advantage of HPS street lighting is the reduction in light pollution.

So IMO HPS outdoors, MH indoors.

[This message has been edited by JBD (edited 01-21-2006).]
Posted By: Rewired

Re: Mercury Vapor bulbs - 01/22/06 05:34 PM

They converted my city to HPS some years ago.. out went the old 400W and 175W mercurys and in went 250W and 100W HPS ( depending on location of the lights).. everything is now a lot brighter while using less power!
Posted By: Jps1006

Re: Mercury Vapor bulbs - 01/22/06 07:20 PM

Even though we all know how to use a search engine, I found this link relevant:
http://www.bchydro.com/business/investigate/investigate763.html

This pocketbook taught me alot about HID the first time I got it:
http://www.advancetransformer.com/uploads/resources/hid-troubleshooting-guide.pdf

Here is the link to the page you can find that pocketbook on. I didn't realize how advance expanded their available liturature. More Sunday afternoon reading:
http://www.advancetransformer.com/resources/literature.jsp
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