Film-Tech Forum ARCHIVE: My rectifyer is abusing my sound-rack

This is topic My rectifyer is abusing my sound-rack in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=004690

Posted by Michael Brown (Member # 890) on 03-21-2003, 11:43 AM:

hmmmmm

nice.

I noticed a few weeks ago that when striking the lamp, the sound system reset. (momentary power loss). Interesting yet I didn't really think anything of it. (we have 2 breakers on two separate fuses)

We had a film last night. Power up the sound rack. Play non-sync for about 25 minutes, then at about 8pm we powered up the rectifyer and struck the lamp...... and fried 2 cards in the CP-55. [Frown]

My engineer has just been and cards are out to repair and he loned us some cards.

So. The basic plan that me and my deputy have come up with is that we will simply strike the lamp before we power up the soundrack. Hopefully that should work.

Posted by Darryl Spicer (Member # 711) on 03-21-2003, 06:25 PM:

The big question is why is it that everytime you power the rectifier you burn something up in your soundrack?

Posted by Daryl C. W. O'Shea (Member # 1303) on 03-21-2003, 06:34 PM:

I'd start checking your electrical grounding, especially around the ignition circuits. Electricity doesn't always go straight (down) to ground -- if you've got a small short to ground in your ignitor it may be finding its way into your rack.

In the meantime I hope your ignitor doesn't automatically strike if the lamp goes out. If it does and your rack runs on one 15 amp breaker, you might want to find yourself a good long 10/3 extension cord.

Posted by Matt Hale (Member # 1518) on 03-21-2003, 06:38 PM:

Check your grounding. I'm not much of an electrician, but I know "seperate circuits" rarely means "seperate grounds" and I have run into all sorts of problems with audio gear sharing ground points with other equipment. Even different electrical panels in different parts of the building may be grounded together. Its possible something in your rectifier or lamp igniter is momentarily shorting to ground, and jolting your sound rack that way.

Posted by John Hawkinson (Member # 1135) on 03-21-2003, 10:12 PM:

Err, I would be wary of drawing many conclusions from what seems to have happened here. No matter how poorly grounded the rectifier/lamphouse or the CP55 might be, frying cards should not happen--what cards were they and how did they fail?

I don't think you have any reason to believe the failure is more less likely with the CP55 powered off...

--jhawk

Posted by Gordon McLeod (Member # 33) on 03-21-2003, 10:44 PM:

I think you have one of theose converted lamphouses if my memory of the pictures is correct
An ignitor that is improperly grounded or supressed can generate sufficient noise to reset or even damage some other electronics
get a competent engineer in to check for the source of the emi

Posted by Paul G. Thompson (Member # 655) on 03-21-2003, 11:23 PM:

I agree with Gordon, Matt, and Daryl.

Once I saw the "fireworks fly" on ignition with an ORC lamp that was not properly grounded.

Make sure all your equipment is properly grounded at all times.

Posted by Darren Briggs (Member # 1071) on 03-22-2003, 06:50 AM:

MIchael,
Who installed your gear? Was is it Jim's friend by chance???
I can recomend a few engineers for you or call acrros myself on a day of if you need some advice.

Darren

Posted by Bruce Hansen (Member # 281) on 03-22-2003, 04:25 PM:

Check for a loose neutral. If a neutral is loose somewhere, unbalanced loads on the (hot) legs can cause strange voltages between the legs and the (loose) neutral. If you have a volt meter, check this.

Posted by Neil McGovern (Member # 1247) on 03-24-2003, 02:57 PM:

Another thing that may be worth checking (if you have 3 - phase power) is that they run off different phases.

Posted by Michael Brown (Member # 890) on 03-24-2003, 03:04 PM:

I'm gunna get the guy who we bought it off (and who did the install) to come take a look.