Par 56 & 64 Lamps

[whitelightlampy]

Two things:

 

1) I'm buying par 300w par 56 and 500w par lamps rated at 2000 hours for the standard £10-£25 price. Some of them don't even make it past the 5 hour mark and it's started to make me wonder why? Does anyone know any tips on how to maximise the life of these lamps and what causes them to break easily?

 

2) Just going through page after page of websites selling these lamps...one said about "preheating" the lamps to give them longer life?

Can you do that and may sound stupid...but how?...as I've never heard of it.

 

Thats all. Just two things I'd like to find out about to try and save on lamp costs :)

[Ynot]

If you're losing these lamps after just 5 hours of use (or even ten times that) I'm a tad suspicious...

 

Where are you buying them from? Is it a reputable dealer or an internet site?

Is there a batch number on the boxes? If so, refer this problem back to the supplier and give them all details about failures you've had.

 

However, there are a couple of things you can check.

Some cheap & nasty par cans don't have sufficient ventilation, so the bubbles CAN overheat, but even then, 5 hours is a touch on the speedy side.

 

Are the terminals in your par can socket clean and corrosion free? Poor electrical connection can lead to arcing, and that can drastically reduce lamp life.

 

Are the lamps correctly rated for the voltage at your site? If you're buying 220v rated bubbles, but the supply in your venue is nearer 240v, then again no surpise they're going quickly.

 

Oh - and preheating...

Some dimmers have an auto-preheat setting whereby it gives all channels a low value output so that bubble filaments just glow. This CAN work, though the efficacy of permanent pre-heat is a debate widely argued all over the place. personally, in a cold theatre I'll usually have two cues at the start of my cue stack - one with around 10 to 15% on all channels to give a warm to the filaments, another around 25 to 50% as a lamp check.

The reason for the preheat is that lamps starting up from cold can suffer from a sudden inrush of heat and yes this can reduce life. But in a theatre that's even tepid in temperature it's not something I'd worry too much about.

[whitelightlampy]

I've been buying them from Blue Aran online. They are all GE pars and all run through 2 dimmer packs. The ones that have been blowing came from Thomann and I believe they made by a company called Osram. I brought one batch and they all seemed to die after one night gigging. Some made it to the next day but nothing more. I just thought of it as a faulty batch so I brought another and the same thing happened!

 

The GE pars seem to be lasting a bit longer...maybe 30 hours...but thats still not even close to the 2000hr mark... :)

 

Not sure what to do as I can't keep buying them to throw away so soon.

[Ynot]

OK.

 

Osram are a decent mfr, so that's one thing out of the way.

 

best next bet is to check the voltage rating on the lamps and then test your supply volts (clean pre-dimmed is best) to see if they're close.

under-rated lamps, as I said, are one quick way to reduce life.

[whitelightlampy]

I shall have a look, thanks for all your help.

 

Maybe I'm just jinxed with bad luck with par lamps :)

[Paul J Need]

And perhaps more importantly - why are you paying £10-25 for a par56/64?

[peternewman]

I had issues with Osram Par 64 1kW lamps from Thomann a while back, I think it was possibly down to them getting manhandled a bit on the journey over, I think the first batch of four all failed, some instantly, the others took a bit longer to go, then a few of the replacements they sent also failed, at which point I got distracted and never really chased it any further. If you still have the blown lamps, a lot of my failed ones, the connections and ceramic on the lamp seemed to have detached around the base where they meet the glass of the envelope.