My 650W blew after 15 minutes !

R

Robert Double

Active member
I got a 240V globe today for my new Britek GY-650. Put it in. Didnt touch the globe at all. All worked for 15 minutes and blink!

The globe I got was a manufactured by OSRAM. I can only presume the globe was a bit duff? What is OSRAM like for QC on there globes?
 
OK so I put my spare OSRAM 650W bulb in again.

10 minutes later blink......

One thing to mention is both times the fuse went as well as the globe going :(

Is it just a bad batch?

I have been using the 300W Britek fine, it's just the 650W playing silly buggers.
 
OSRAM is a decent brand. It sounds like a voltage problem with your insrument. I'd take it back and get a replcement.
 
If the fuse went down, it could very well be a short circuit. There is probably some bad wiring on your fixture. Either find out where, or just send it back...

Good luck...
 
Is the lamp rated for 240V? If you're in North America I'm pretty sure you're supposed to globe your lamp heads with lamps in the 110-120V range. Can someone confirm?
 
bcheong I live in Australia so I am using 240V rated globes as specified on the silk screen of the Britek light.

I hope it isn't a light problem as I got it from Tom @ Rostronics in the US, so sending it back could be a bit of a pain.

I find it hard to believe the wiring the light would be dodgy, only because it is so simple. It's not like there are any circuits in the darn thing. And the light works fine for 10 or 15 minutes before blink. So it would point to maybe it getting warm?
 
The fact that the mains fuse open concurrently to the failure of the globes indicates that the globes are failing short (and therefore consuming excessive current and opening the fuses). I would suspect a bad (or mislabeled) batch of globes. You could have a very high mains condition (easy enough to confirm) but this is unlikely.
 
I am with you on your thinking khmuse. I have spoken to my globe supplier here in Australia and he has been very accomodating in what has happened, with us both suspecting the globes.

However I do live in a unit on Manly beach; the block has about 200 odd units, so I am wondering if there is also something a little weird in the mains voltage here? How can I confirm the condition of the mains? You eluded to that it was easy to confirm?
 
Just grab any reasonably calibrated DVM and set it to AC Voltage measurement mode and measure your actual mains. The typical range is about +/- 3% so anything above 247 would be anomalous.

Remember, that the formula for power is:

P = E^2/R

So if the Voltage increases by 10%, then the power increases by 21%.
 
OK just done the check with the DVM. The voltage goes up and down between 245V and 252V.

I thought Australian mains should be at 230-240V Is such a fluctuation of 245-252 normal? Reading khmuse's post 252 would seem a little high, and probably explain the globes popping.

Done a bit further research on the electric supplier here in Australia and this is what they say -->

When EnergyAustralia identifies or is notified that the steady state supply
voltage is outside the limits below, EnergyAustralia will take reasonable
steps to modify the network to achieve the objective and if possible be closer
to 253V and 226V as the upper and lower limits respectively.

5.1.1 Low Voltage Network

EnergyAustralia’s objective for the operation of its network is to maintain the
steady state phase to neutral supply voltage (ten-minute average) within the
following range:
• upper limit: between 253 V and 264 V.
• lower limit: between 226 V and 216 V.
The nominal (mid-range) voltage is 240V.

The relevant Australian Standard for supply voltage range is AS 60038 2000.
 
Yeah, that is a somewhat high mains condition (I would be contacting your power supplier and complaining as this will have deleterious effects to a lot of things around your residence).

It could be that both a bad batch of globes and a high mains condition have conspired to make your life difficult. Funny how the universe works like that, but often there isn't a single root cause to every effect we experience.
 
I have a problem with my 1k briteck. The light would stay on for a maximum of 15 minutes then just turn off. The fuse was fine and intact, and the light bulb was ok. In fact after about 5 minutes I could turn the light back on and the same thing would happen 15 minutes later. I thought that my sources of power were bad since the two places I shot had either old wiring or multiple lights running on one circuit. I took the light home and opened it up. I took the bulb out and inspected it to find that one end had some damage from what looked like corrosion. I looked inside the housing at the metal knob where the light touches on either side where the bulb gets power and on one side the same thing. The metal knob had a bit of what looked like corrosion. I unscrewed the white porcelain type material that connects to the metal knob and as I got the screw out a piece of the porcelain dropped to the floor. It was a piece right around the screw I just took out. Because of the broken piece of porcelain it makes me think that the pressure from the broken porcelain side was not the same as the other side which made the connection weak resulting in electricity arcing and corroding the knob and the bulb end. I've since tightened the piece back down and it seems to be working fine for now. I'm going to turn the light on and I'll repost if it's still on in 15 minutes.

-Kevin

UPDATE:

The light turned off after about 15 minutes again. I took a screw driver and touched the glass part of the bulb and walah the light turns back on. I know now what the problem is and how to solve it. When the light heats up it slowly turns the metal straps and posts at either end of the bulb a bit less rigid and the connection after about 15 minutes is so lose that the light it slips out of it's housing at one end or the other. It turns off because the connection is lost! Briteck needs to make the metal strap and posts that the wires connect to at either end thicker so when they get so hot they don't warp and lose the connection. The way I fixed this is after 15 minutes when the light turns off I adjust the bulb to the center so both sides are still touching and I just make sure the light doesn't get bumped. I'll most likely try to install some high tension springs behind the straps to solve this problem more permenantly in the future. The corrosion was cased by arcing electricity by the way. I monitored the light the last 10-15 minutes right before it shut off and I heard a buzzing/crackling sound coming from the corroded side. I put on 5 pairs of sunglasses I had from a recent shoot to look directly at the light to see what was going on and after about 1 minute I saw a spark of electricity and the light went off. The elcetricity was jumping a small gap and I think that is what was making the sound.

Hope this helps somebody else out.

-Kevin

khmuse..I think I'll move this to a separate thread since it seems to be a totally different problem.
 
khmuse-

What could be done if the utility company cannot provide more regulated power?
Is there an in-line "black box" solution available to the consumer? Thank you for your insight.

-Brian
 
thisiswells said:
khmuse-

What could be done if the utility company cannot provide more regulated power?
Is there an in-line "black box" solution available to the consumer? Thank you for your insight.

-Brian
Click to expand...

Depending upon the amount of power that you need, there are several solutions. One would be a decent sized Variac. This has extra advantages as it can be used to dim or brighten the lamps besides just solving your high mains problem. A 2 kVA one can be had for around $200 - $250. If you need a lot of power, then I would recommend an autotransformer. You can get a 50 kVA one for under $1000, but its big, heavy, and fairly noisy.
 
Startling discovery

Startling discovery

I think I have made progress as to why my globes are blowing after 10-15 minutes. Both the globe and the fuse were going up, and it was getting costly.

I took the light apart to check for any wiring problems, and there are none. There aren't even any signs of burning or the like. So this had me really stumped. But today I took a closer looking at the globe fitting / holder.

holder.jpg


As you can see the pin sockets for the globe are both different sizes. Unfortunatly I don't have the blown globes here to check the pin sizes as my globe supplier wanted to check them out, but from memory the globes had identical size pins.

But my theory is. If one of the pins aren't making full contact, then after 10-15 minutes its going to get pretty warm, and then possibly starting to arc and ka-pow! Does that sounds reasonable?

I am getting some new globes on Tuesday but if someone could check there DYR 650W's before Tuesday to see if the pins are the same size that would be really appreciated?


Robert
 
Robert Double said:
But my theory is. If one of the pins aren't making full contact, then after 10-15 minutes its going to get pretty warm, and then possibly starting to arc and ka-pow! Does that sounds reasonable?

Robert
Click to expand...

Thermal expansion could cause arcing, but arcing is not going to cause an open fuse as arcing is nothing more than ionization. Arcing could easily lead to damaged contacts, which could lead to an open condition; however an open isn't going to lead to an open fuse. Look at both the contacts in the fixture and on a globe for evidence of arcing (discoloration, pitting, etc). A failed globe is much more likely to cause a fuse to open (unless the fuse has been subjected to external overheating) than a contact issue. A close up image of either contacts might be useful. Have you measured any of the failed globes to verify their status?
 
I have been speaking to my globe supplier and he confirmed that the globes had different size pins. So my theory of arcing, and loose connection is out of the window.

khmuse-> Unfortunatly I don't have the globes anymore as I sent them to my supplier as he was more than intrigued, so I cant perform any more analysis on them. One thing that might help; the fuse definately blew! So much that the fuse came out in pieces (it broke the glass). The globes also got well cooked.

The picture in the above posting are the actual contacts from the light. As you can see there is no sign of any sort of damage??
 
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