Electrical question (high presssure sodium)

[Jess from VA]

The 50 watt HPS on my front peak started cycling off and on all night after 20 years, so I figured the ballast went out.  I thought to replace the ballast in the existing light, but none of the sellers was much help in advising which ballast to use (there are multiple choices), so I decided to just get a new light unit.  

You go online and read reviews and discover so much foreign stuff craps out quickly, or breaks on install, or the globes blow off, so I decided to just buy local so if I have a problem, I can take it back quickly rather than deal with Amazon and shipping.  Good thing, the first light I brought home I bench tested and the light sensor was no good (stayed on in bright sunlight).

But I could not find a 50 in the style light I wanted (the mount nicely boxed in my vinyl siding), so I got a 70W.  I managed to not fall off my ladder or get electrocuted, and it works great (so far), but man that thing is bright.  I like HPS because it is a low draw, long bulb life, and a neighbor friendly soft yellow light, but this new 70 is much brighter than the 50 I replaced (which was probably dimming with age).

So here's the question:  Can I run a 50W HPS bulb in my 70W HPS unit?  I don't mind if it shortens the bulb life, but I don't want to burn out the ballast or burn my house down.

You'd think the answer could be found on the all powerful interweb, but I could only find a single Q & A on this question in a lengthy search, and some guys said it would be fine and would only shorten bulb life as the ballast would overpower it, but one guy said it was a fire hazard and/or would blow the ballast.

What I did discover, is about a million guys are growing weed under lights and happy to talk about it online, with every Q & A under the sun about lighting, power, wiring, timers, yada freely available.

Thanks for any advice.    

[Serk]

I don't have direct answer to your question, but a tangent, have you looked into replacing the whole mess with LED? One of my other hobbies is saltwater reef aquariums, and I had a few thousand watts of metal halide lighting, about 2 years ago I replaced it all with LED, saved about $2,000 a year in electricity + less heat generated + MUCH longer bulb life... Might be worth a look to see if just ditching it all and going with an LED setup might be a better option at this point instead of tinkering with part of an old HPS system (Which is similar to metal halide)

Too bad you weren't around here, I literally gave away several high end electronic metal halide systems, 175 watt and 250 watt ones.

[Jess from VA]

Yes, I had a talk with a local guy about LEDs before replacing my HPS.  The prices have come down, AND I guess I can get enough light out of one to adequately light up my big corner lot front yard.  But I also have 3 existing 35W HPS on the other three sides of my house (mounted lower to not be in my neighbors eyes),  and I really like the soft yellow light, and really dislike bright white lights (like halogen or mercury vapor), and assume that is what LEDs will give me.  Cuts down on the buggies too.

I have been running them for 20+ years all night every night, and my power bill is pretty reasonable, only going over $100 a month a few times in extended AC heat waves (gas heat). Except for July and August, my bills are much lower than that.  

I just did not feel like going to the time and expense of a 4 light change-over, when what I have been using has worked so well for me.  Bulbs last 5-7 years.  

Some neighbors already call my place a fort; if I went with 175 or 250 metal halide it would draw too much attention.  LOL  

[Hotrodwing]

Jess you cannot change out a 70 watt lamp for a 50 watt unless you change the ballast also, sorry.

[DK]

I have been running them for 20+ years all night every night, and my power bill is pretty reasonable, only going over $100 a month a few times in extended AC heat waves (gas heat). Except for July and August, my bills are much lower than that.    

I love your electricity rates. Ours runs $400.00 + during A/C months in Little Rock.

We have one outdoor security halide light which is flat rated for $10.00/mo.

Dan

[The emperor has no clothes]

What I did discover, is about a million guys are growing weed under lights and happy to talk about it online, with every Q & A under the sun about lighting, power, wiring, timers, yada freely available.

Thanks for any advice.    

It's ok Jess. If you need some new lights for growing weed we are here to help. 

[wiggydotcom]

Jess, what I've always been led to believe is that if a sodium is cycling, it's a sign the lamp is going bad...and to change it before it takes out the ballast. When I was on lighting detail at Cat, we would look for the short cyclers and change them out quickly. If we got to them in time, the ballast would last a long time.

I've also read you should keep the same wattage as what the fixture came with. Not real sure of the "how comes"?

[Jess from VA]

When you say a sign of the lamp going bad, you mean the bulb?  I had just replaced the bulb, before the cycling started (or rather the cycling had just very occasionally, once in a long while, started).  With the new bulb, it cycled constantly, and like every 4 minutes (had to be a heat issue).

I would like to have changed the ballast as the light that came down (exterior) was better quality than the spun aluminum new one that went up.  But when I got the old one on the ground and took it apart, it really looked bad and burned up in there (20+yo).  I could not get good information on what exact ballast to use in replacement, and the $20 extra (over the cost of a new ballast only) to just buy a new unit beat the time and headache it would have been to wait for shipping of a maybe-correct ballast, hoping that was all I needed for it to work (some of them come with new igniters some don't).

I am holding on to the old light for awhile to see if the new one develops any problem in the short run.  

[bigguy]

I have absolutely no experience with this product, but thought you might want to look into it.

[wiggydotcom]

When you say a sign of the lamp going bad, you mean the bulb?  I had just replaced the bulb, before the cycling started (or rather the cycling had just very occasionally, once in a long while, started).  With the new bulb, it cycled constantly, and like every 4 minutes (had to be a heat issue).

I would like to have changed the ballast as the light that came down (exterior) was better quality than the spun aluminum new one that went up.  But when I got the old one on the ground and took it apart, it really looked bad and burned up in there (20+yo).  I could not get good information on what exact ballast to use in replacement, and the $20 extra (over the cost of a new ballast only) to just buy a new unit beat the time and headache it would have been to wait for shipping of a maybe-correct ballast, hoping that was all I needed for it to work (some of them come with new igniters some don't).

I am holding on to the old light for awhile to see if the new one develops any problem in the short run.  

Yes, I meant the bulb itself. Doesn't mean the ballast can't go bad first though. I think it was a good idea to change the whole fixture.

[FryeVRCCDS0067]

My understanding of these lights agrees with pretty much everything that has been said. Sometimes when they start cycling on and off it will just be the bulb but usually I would soon have to replace the fixture or ballast. I was taught they always have to have the same wattage bulbs they were designed for installed. Otherwise, thermal calamity could result. I worked in a very hazardous plant as far as fire risk goes so I never tested it.

We had a lot of these at my former plant, I never cared much for them, ours never lasted close to as long as yours have. I eventually started replacing them with motion sensing LED's which are, as you said, "very white".

My favorite security lights around my gun-shop came from Menard's. They auto run at half-bright when the sun goes down and bump up to full bright when the motion sensors see something. Wind blowing the leaves in the trees, people, animals and vehicles cause them to bump up in brightness. they use standard screw in bulbs and the bulbs last virtually forever. Probably not what you would want though.

[Jess Tolbirt]

if it is cycling on and off the only problem is the lamp,,in answer to the question a simple answer is NO,,,,unless the ballast has stated on it that you can use certain lamp with that ballast..
some ballast are useable with more than one type bulb,,but yours is probably not..

[Jess from VA]

Thanks guys.