HPS Troubleshooting: turns off after three minutes

[m.060.mm]

Title pretty much covers it. My friend gave me a 150W HPS that keeps turning itself off.

It starts as soon as it's plugged in. Warms up. Maybe two minutes after being at full brightness, it cuts off. Down for about 30 seconds then it warms up again - notably faster because it's already hot. Cycles through this indefinitely.

A shame to throw it away, right? He said he tried replacing the bulb (I guess this is typically symptomatic of dying bulbs) and no success.

I realize if it's not the bulb, it's likely the ballast but if that's the case, I probably won't bother as the ballast is the expensive part and I don't need a tiny light.

Just hoping someone has experienced the same and found a solution that didn't involve buying a new one.

What are the odds of the ballast overheating within a few minutes? It continuously hums throughout cycles so I'm not sure it's the ballast because it's operating throughout.. but what else could it be?!

[The Backdoor Man]

yeah its the ballast. it gets too hot so it shuts down until its cool enough to start back up again.
I would take it apart, look and see if anything looks out of the ordinary

[m.060.mm]

http://i.imgur.com/DggEk.jpg
http://i.imgur.com/9zNmg.jpg
http://i.imgur.com/ja8uP.jpg
http://i.imgur.com/o1rAo.jpg

It doesn't look like there's a whole lot worth tinkering with.

The pink sticker says to replace the whole unit if there's a problem. But I never liked stickers anyway.

The label reads the right wattage but thinking about it do all 150W HPS bulbs work on a certain amperage? Could the bulb be the wrong type for the ballast? They're both HPS. And I'm guessing, even with limited electrical knowledge, that the bulb can't really be 'wrong.'

[Slapshot]

PROBLEM 3— LAMP FLICKERS OR CYCLES ON AND OFF

POSSIBLE CAUSE
CORRECTIVE ACTION

1. Wrong Ballast
With mercury lamps, improper ballasting can cause flickering or erratic operation. With metal halide lamps, the effect is generally noticed in the startup period when the lamp ignites, starts to warm up and then extinguishes (cycling). This may be caused by improper voltage/current relationships delivered by ballast. Under certain conditions new lamps may "cycle". Usually after three tries to start at 30 to 60 second intervals lamps will stabilize and operate normally.

2. High Lamp Operating Voltage/Low Open Circuit Ballast Voltage Measure lamp operating voltage. Measure ballast open circuit voltage. Replace as required.

3. Variable Voltage
Heavy motor loads or welding appliances on line can cause flickering during operation. Remove lighting circuits from the circuits serving these devices. Provide voltage regulators. Check for loose connection. Use of Constant Wattage Isolated (CWI) ballasts not Constant Wattage Auto (CWA) can frequently help this situation.

4. HPS Cycler
As a high pressure sodium lamp is burned for long periods of time, its operating voltage tends to increase. When this point is reached, the lamp will exhibit cycling on and off characteristics. This is normal end of life lamp. Replace the lamp after checking ballast open circuit voltage and lamp operating voltage.


HID troubleshooting guide (http://atlaslightingsupply.com/HIDtroubleshooting.html#PROBLEM 3 Ð LAMP FLICKERS OR CYCLES ON AND OFF)

I read a little about this when I bought mine, sounds like it's either overheating or it's an old/faulty bulb. I get my bulbs for $6-8 each here (http://www.needabulb.com/High-Intensity-Discharge-HID-Bulbs-C18.aspx)

[m.060.mm]

Wtf, how are those so cheap?

You've ordered em and used them? Do they burn out significantly faster?

I wouldn't expect incredible value for that price but are they at 'worth it?'

[Slapshot]

Wtf, how are those so cheap?

You've ordered em and used them? Do they burn out significantly faster?

I wouldn't expect incredible value for that price but are they at 'worth it?'

Yea, I've been using the same bulbs (HPS&MH) for 9 months now, probably need some new ones myself at that price. The more expensive specialized bulbs (agro) are worth it I've been told, but the cheap ones do just fine for my needs.

[zombo.com]

most hydro shops will test a light for you, if you've got one in the area take that sucker in and ask them to hook it up and see if they can identify the problem. they've got the equipment, and most of them are halfway decent plumber/electricians from troubleshooting their own grows.

[eesakiwi]

I had this happen too.

It turned out to be a broken weld connection inside the bulb.
Where the inside bulbs wire was supposed to attach to the long wire going thru the length of the outter glass bulb, the connection was broken.

I found they (who?) can reweld them using a laser..... yeah right.

But what was happening was the ballast would start up & the light would glow & start.
Then as the wire heated up it expanded, the wire connection would shift & break the flow of power & then the bulb would stop.

Then the damn thing would cool down, only to start up & go thru it all again.
Brand new bulb too.

[zombo.com]

I had this happen too.

It turned out to be a broken weld connection inside the bulb.
Where the inside bulbs wire was supposed to attach to the long wire going thru the length of the outter glass bulb, the connection was broken.

I found they (who?) can reweld them using a laser..... yeah right.

But what was happening was the ballast would start up & the light would glow & start.
Then as the wire heated up it expanded, the wire connection would shift & break the flow of power & then the bulb would stop.

Then the damn thing would cool down, only to start up & go thru it all again.
Brand new bulb too.


that's a bitch, under warranty at least?