I fry my Red Head Bulb all the time. What am I doing wrongly? What Kind of generator should I be using?
Posted 06 July 2015 - 02:53 PM
Posted 06 July 2015 - 03:40 PM
Unstable/over voltage from the generator. If you were able to monitor and record voltage output over time (something like a Dranitz), I'd bet you would see a recorded spike in voltage when a bulb/globe/bubble/lamp fails. With a Digital Multimeter or VOM, what is the voltage output of your generator? 220 or closer to 240 VAC?
Posted 06 July 2015 - 05:17 PM
Posted 06 July 2015 - 05:18 PM
Posted 06 July 2015 - 06:15 PM
Have you ever metered the output? Are your lights the only load on the generator or is video village, HMU, etc., also tied into the same power? Are these little portable units, 5-6Kw (put-puts), larger gas or diesel rigs, 100A , 250A? Do they have a provision for manual voltage adjustment?
Posted 06 July 2015 - 06:34 PM
Posted 06 July 2015 - 06:45 PM
Okay, we've established that they are portable generators, up to 6Kw. Probably don't have a manual voltage adjustment. Voltage is probably maintained by an electronic or more likely mechanical governor. It's possible that this (internal) setting is no longer keeping voltage in a safe range for your bulbs. Is there an Electrician around during an even or shoot who could check the voltage produced?
Posted 07 July 2015 - 09:07 AM
Is that image exactly the generator or just one similar to the portable generators you have to work with? Do you experience the short lamp life on every generator or just some of the units provided? You really need to find someone with a meter or buy one yourself. Really simple to use. Doesn't have to be digital to be useful.
Posted 07 July 2015 - 10:04 AM
There is some pattern here, a trail of clues, that's causing you bubs/globes/lamps/bubbles to fail prematurely. Something in the details that you are not telling us or not noticing yourself. I'm just clutching at straws.....are the sockets tight and free from corrosion?
Posted 07 July 2015 - 06:48 PM
There is a poster here, Guy Holt, who has a number of posts about using generators and movie lights. Unfortunately one does have to be a bit knowledgeable about electrical systems to understand what he is talking about, and how to understand your particular problem.
I would ask, what is the wattage of the 'red heads', and what is the power output of the generator. From the above, it seems the generator is 6KW.
I don't do power analysis much in the modern era, but my rule of thumb was to have twice as much power available from the generator as the load. So, if you had 3 1KW lamps, then 6KW is a 'bare' minimum.
One thing that Guy Holt stresses, is that the HMI load is not a 'nice' load, and has what is known as odd harmonics. Again, this requires an understanding of Alternating Current, and how the devices that are powered by the generator respond.
You also have to understand that the power cord length from the generator to the HMI ballast can also affect how much power is delivered, or the effect of the harmonics may be.
Putting 100 feet (30 meters) of power cord between the generator (to cut down the noise of the generator heard at the set) may impact the power delivered.
I don't know if HMIs cutout because of low power, or increase the speed to failure if one does not have the correct voltage.
HMIs do require a cooling off period before striking the lamp again.
Here's an article on the topic of how much power for a generator to give, for some set of lamp wattages. It does get technical, unfortunately...
Posted 07 July 2015 - 07:59 PM
It's not an HMI, it's a Tungsten fixture. No harmonics, it's a pure resistive load. The wattage is either 800 or 1000w depending on which globe you choose. A long run of light gauge power cord may introduce a voltage drop, but it's not going to cause globes to fail.
Posted 07 July 2015 - 08:27 PM
If you rig one of your lights off mains power, pointed sideways, with nothing on the front, how long does the bulb last?
Posted 08 July 2015 - 10:17 AM
Posted 08 July 2015 - 01:37 PM
Ok, somehow I got the idea that they were HMIs... but from the pictures... uh... Were this my problem, I'd get a power strip with enough plugs for the number of lights, and that could carry the 2.5 KW requirements.
If there were no such power strip. I'd probably build one so that all plugs had their three prongs in contact, and nothing was left 'chance' with splicing or twisting the wires.
A hardware store should have the raw materials to do that. As a matter of fact, I've bought something like that to tie into power at conferences where the conferance
Something like this (this has standard US 3 prog plugs for distributing the power, but I'm sure there's a Euro/British version in your region.
Posted 08 July 2015 - 02:42 PM
That's a twistloc to edison adapter not a "cube tap". His lights are should have 220v bulbs in them. You're confusing the issue.
Afolayan, does the volmeter on the generator you pictured work? When two lights are plugged in what voltage does it read? 220 or closer to 240?