broken dimmer pack's

zac850

Well-Known Member
Joined
Nov 21, 2003
Location
New York
Ok, heres the problem. I have a 16 chanel bord, and 2 dimmer pacs, with 4 circuts on each (so a total of 8 chanels). 2 of the channels weren't working, so i checked the fueses, saw that they needed replacing, and replaced them (250v, 6.3amp, insteed of the normal 250v, 10amp).

I then hooked up the lights, fliped the circut on for the box, and the light turned on. I didn't even turn the dimmer pack on, the light just turned on by its self. I umpluged the DMX from the bord to the pack, and the light stayed on. I have 2 dimmer pacs, and the DMX signal goes from the bord to pack 1, then into pack 2. Each pack has one circut that dose that (its number 4 on the first box, and number 3 on the secound box).

Dose anyone have any idea whats wrong? Is it fixable, or do i need to get new dimmer packs?

Im at home, so im not sure the brand and/or type of dimmer pack or bord, but ill find out tommorrow at school...

Thanks so much,
Zac
 

wolf825

Senior Team Emeritus
Premium Member
Joined
Apr 7, 2003
Location
Eastcoast USA
zac850 said:
Ok, heres the problem. I have a 16 chanel bord, and 2 dimmer pacs, with 4 circuts on each (so a total of 8 chanels). 2 of the channels weren't working, so i checked the fueses, saw that they needed replacing, and replaced them (250v, 6.3amp, insteed of the normal 250v, 10amp).

I then hooked up the lights, fliped the circut on for the box, and the light turned on. I didn't even turn the dimmer pack on, the light just turned on by its self. I umpluged the DMX from the bord to the pack, and the light stayed on. I have 2 dimmer pacs, and the DMX signal goes from the bord to pack 1, then into pack 2. Each pack has one circut that dose that (its number 4 on the first box, and number 3 on the secound box).

Dose anyone have any idea whats wrong? Is it fixable, or do i need to get new dimmer packs?

Im at home, so im not sure the brand and/or type of dimmer pack or bord, but ill find out tommorrow at school...

Thanks so much,
Zac

Hiya,
A few thoughts off the top of my head--those packs sound like they are "tree pack" dimmers (Dove or NSI perhaps?)...4 600w or 1200 watt circuits in one portable pack usually with one or two power plugs attached to it. Usually those have a DIP switch addressing system or a set of test switches next to the addressing system--and some of the dip switches if set properly in sequence & turned on can act as a "hot patch" to turn on a single circuit. Sounds like what has happened..

Also to consider--many of these tree pack style dimmers will go full-on if you disconnect the DMX from the console or the DMX signal is not present...usually it is on all channels but I suppose it could be just one or two circuits.

Check out your dimmer packs, post more info and check the dip switch settings would be my first suggestions... Also--some of those dimmers when a fuse blows will have a "reset" feature which will need to be activated when you put in a new fuse. The fact you put in a smaller fuse shouldn't matter to the power being on always...except for the fact that if you try to put in any light over 575w / 600w you will blow the fuse sooner then if you put in a 10 amp fuse as is spec'd.

wolf
 

ship

Senior Team Emeritus
Premium Member
Joined
Mar 29, 2003
Location
Illinois
Were the fuses you replaced for the same channels that are now giving you problems? Were these control channels malfunctioning before the fuses blew?

Could be that, and I'm not a dimmer or electronic expert, but it could be that the circuits given bad fuses also have something electronically bad with the dimmes such as they are fused to the open position. A diode or something somewhere blew out before the fuse could protect it. I have some household dimmers that are either on or off with no dimming left. Probably something similar. Could just be something that can be cleaned but it's doubtful.

Do you have an electronics department at school? This is up their alley to service for free. Otherwise, it is something that needs to be professionally repaired.

Can you run a show by not using the channels? Probably, but it's never wise to do so because you never know what else might be wrong given the above problem. Blowing that fuse means something plugged into the dimmer that either was well over loading it or shorted it and who knows what could have been destroyed inside the dimmer before the fuse blew. I'm overall responsible for blowing the zener diodes on 13 MiniMac fixtures by wiring a AC Distro for 208v in a way someone wishing it to be 120v might get confused about. That was not a cheap repair in man hours. Fuses did not blow in time to protect the electronics.

Could be on a larger dimmer or lighting system that they were locked into the open or off/on mode, but I kind of doubt that's possible with a little 4-channel 600w per channel pack much less the light board in a soft patch given the description.
 

cruiser

Active Member
Joined
Oct 11, 2003
Location
Melbourne
I had this problem with one of my racks at school.

They are the circuit breaker type... it really started to annoy me and i couldnt go without hte channels.
They were sent off cuz I couldnt find it with a multimeter, and there was some problem on the circuit inside, didnt take em long to fix...

BTW, are dimmers called dimmer packs in america, cuz we call em dimmer racks??
 

ship

Senior Team Emeritus
Premium Member
Joined
Mar 29, 2003
Location
Illinois
A dimmer rack would imply a rack of individual dimmers such as a sensor rack. In this case it's not individual dimmers in a rack, it's a pack of two to eight dimmers as one "shoe box dimmer" or tree dimmer pack that's powered up off one or two 20A power source that's plugged into a wall. The 20 amps is in this case divied up into four 6 amp circuits.

So we kind of use both terms as I'm sure you do also.
 

zac850

Well-Known Member
Joined
Nov 21, 2003
Location
New York
Thats for all this reply. What I was hopping for was a really quick fix, like "turn this 3/4 of the way left, and it'll be fine, but after fussing with it for another 3 hours today, i have all but given up hope for the dimmers... Im going to ask the head of the theater department if he could find a place in our non-existant budget to get us a new system...

HAHA, I WISH

anyway, thanks for all the response,
Zac
 

ship

Senior Team Emeritus
Premium Member
Joined
Mar 29, 2003
Location
Illinois
over fusing the dimmers would probably be a really bad idea. If they are blowing plus wiping out the electronics at 6 amps, what could 40 amps worth of overload to to the dimmer given it's fed by a 20amp circuit plus a 20amp cable? That in addition to a electronics package that already seemingly can't handle the overload.
 

zac850

Well-Known Member
Joined
Nov 21, 2003
Location
New York
yea, they were 10 amp fueses, and i put 6.3's in, however, today i looked at the bottom of the packs and saw that they are soposto be 6 amp fueses, not the tens which we put in....

i am basicly calling it quits for this bord. we can use it, but its getting bad... Im going to see if we can dig into the 3 dollar budget and buy a new lighting system, or see if we can get one donated to us... were a non-prophit school, so if anyone would like to donate anything...

we could also use a theater, insteed of sharing the gym....
 

Patches

Member
Joined
Dec 3, 2003
Location
Salem (Podunk) Oregon
Does anyone here have a strand system? Well my school does... that means blown dimmers left and right... int the middle of shows and everything... Anyway, i was wondering if it's natural for the system to only have a ten year shelf life, and why after five, many are only usable through hot-patching... Or am i alone in this?
 

ship

Senior Team Emeritus
Premium Member
Joined
Mar 29, 2003
Location
Illinois
Probably a good time for a service call. Such things are supposted to be done every year.
 

cruiser

Active Member
Joined
Oct 11, 2003
Location
Melbourne
I am using a strand system that was built in 1965, and its still kicking along pretty well.
We do a show at this hall once a year, so for the past 3years I have been getting it serviced when we bump in by an electrical engineer.

Although, Old analogue strand systems will have some problems when running a new digital desk on your analogue dimmers. If you are doing that let me know, we found a way to get around it, thats what our strand racks down there have been doing...
 

Mayhem

Senior Team Emeritus
Premium Member
Joined
Jan 21, 2004
Location
Australia
First place I would look is the optocouplers. These are little devices (usually 6 pin IC's) that control the output triacs. Most dimmers have these mounted in sockets so that they can be quickly replaced. The easy check is to swap the one on the faulty chanel with one on a chanel that works. The optocouplers are located close to the triacs and shouldn't be too hard to locate.
If this is not your problem you have 2 options, take it somewhere to be fixed or measure components on the faulty board and compare your results with a working board.
Hope this helps (if you have not already gone for option 1 or option 3 (which is to use it as a boat anchor))
 

Users who are viewing this thread