Film-Tech Forum ARCHIVE: What amps should these lamphouses be running at?

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Posted by Kevin Wale (Member # 1851) on 11-30-2003, 02:48 PM:

We have two EPRAD Universal Lamphouses. One is running off of a Zetron N3-X75DM(45-75 output amps) Rectofier, and the other off a N3-X7595DM(45-95 output amps).

The smaller has been running under 60 amps and has been dark. The bigger has been running a bit over 60 amps and flickers.

I think the smaller needs a bulb change (I haven't been here very long and I'm still trying to find out all what has been done when and where to what.) I also think if flickers but isn't noticable because of the dim bulb.

On the bigger, Matrix Revolutions for example, flesh tones in people would change colors. It was just dark in the smaller.

If it helps the projectors are Century Model C.

Posted by Richard Fowler (Member # 893) on 11-30-2003, 02:53 PM:

What size bulb are you using?

Posted by Travis Hubrig (Member # 1745) on 11-30-2003, 03:08 PM:

It is also possible that you have some bad diodes...
I have Xetron rectifiers...diodes are the most common problem with flickering that I have.

How many hours on your bulbs?

Posted by Kevin Wale (Member # 1851) on 11-30-2003, 03:50 PM:

I believe they are 2000W bulbs.

Not sure on the hours on the bulbs yet. Answers seem to be confused so far... So and so was supposed to do this and that. No no no, so and so did that because of that. And of course yet another story in thier also. It's not really anyone's fault except people seem to just not understand each other here sometimes. Someone will say something and another meaning than what they intended is what is often taken. Not sure why but it's not a lack of communication, just a lack of understanding. Not real sure how to deal with it yet. For instance, I thought I moved 2000 miles to be the manager. In fact, I moved to be one of the managers(there are now two of us who don't answer to one another at all but are on the same leval.) Looking back, I don't know that it was said that I would be THE manager in so many words. The word manager here doesn't signify what I tend to think of it signifying. That is for someone to say he's the manager, they in thier mind are thinking what I would say as "he's one of the managers."

I think that is why it's so hard to find out exactly what has been done maintanence wise.

I know the tech was here not too long ago on a pm but I was here visiting before he came and there was ghosting on house 1. I come back when I take the job and there is still ghosting after the pm. I was the first person to notice when I interviewed, and I was the only person(aparently) who noticed that there was still a problem.

Posted by Richard Fowler (Member # 893) on 11-30-2003, 04:05 PM:

Get a new tech if he did not catch the ghosting on a p.m. call with some RP40 or equal visual test film...unless there is a money issue to prevent a proper call. If the bulbs are 2000 watt and are old they should be running at 70 - 75 amp. The flickering you may be seeing could be that the arc spot is wandering due to low amperage to the old bulbs.

Posted by Kevin Wale (Member # 1851) on 11-30-2003, 05:44 PM:

Ok, I have house 1 at 75 amps. I turned on house 2 and the meter doesn't change. If I tap on it, it moves. All the way down, up to 60, back to 55. If I push the amps/volts view switch, it goes up to 120 volts. When I let go, it goes way down and if I wiggle that switch the meter moves again. I think there are some problems with the switch and meter. (Totally obvious comment of the day. LOL)

I tapped the meter and the bulb hour gage fell in. Quality stuff here.

In anycase, I have no idea what house 2 is running at, but house 1 still flickers with it running at 75(assuming that meter is actually working because it was acting up the other day too.)

I'm really concerned because I was told there have been shorting out issues with these lamphouses before. I'm definately going to ask the owner if I can get a tech in this week asap. I just don't know if I should call whoever she has been using.

Anyone have a recommendation of a good tech in the D.C. Metro area?

Posted by Richard Fowler (Member # 893) on 11-30-2003, 08:11 PM:

Faulty ampmeters are no help. Eprad has not manufactured lamphouses for 10 years so it should not be factory fresh [Wink]

U.V. from the rear of the bulb destroying the insulation to the internal wiring harness, corrosion to the rear bulb support and an internal blower which is hard to service and lubricate are features of this lamphouse....depending on which model you have, the reflector is probably pretty doggie. Years ago we would systematically reharness, replace meters, mount an external blower on top to restore these into service. The ignitor was rarely a problem. Time to have your tech check the system out....especially the ampmeter.

Posted by Kevin Wale (Member # 1851) on 11-30-2003, 09:10 PM:

Thanks for the info Richard. That helps a lot just to know a bit more about these things.

If anyone has any recommendations for a tech that would be great. I'm just really leary to call whoever has been doing it because of the continual problems I keep discovering. It really seems things haven't been maintained well at all before I got here. The thing I'm afraid of now is the combination of likely failures beginning with the high cost of fixing all the problems.