Dimmer Flicker

[Dweeks]

Hi guys,

 

I oversaw the installation of a new lighting system at a school in Buckinghamshire, installed by AC Lighting a couple of years ago. More or less since it was installed, I've noticed the output current flucuates when a channel is on 20-40%, approximately. All lanterns on the circuit flicker at the same rate.

 

The dimmer is a 12 channel Anytronics, run by a Zero 88 Level 12. Outputs to 15amp sockets all hard wired. (No Patch Panel). I've tried it off a couple of desks and still have the same problem.

 

 

It's not a massive issue, but its obviously not right... Is this the result of a crappy Dimmer, or poor power supply... any suggestions?

 

Once the next show is complete, think I'll call in AC Lighting to have a look, but just wondered if anyone had any advice.

 

For the record, it has a 32amp feed, running 6 x 650w quartet lanterns, and generally 6 Par 64's (500w).

 

As an addition to this, I've just been told we've blown our second brand new parcan lamp in a week... They've been on for maybe 10 hours each?

 

Could this be related?

[Tomo]

Sounds like a faulty dimmer or a poor power supply.

My bet would be a faulty dimmer.

 

As to the parcan lamps - yes, it probably is related.

If they spend a lot of time flickering, it will load the filament more than expected.

 

On the other hand, I'd expect par lamps to take it better than that - do you have cheap ones?

[Dweeks]

Ok yes, they are cheapo Omnilux 500w lamps from Thomman, but one blow I can live with, two is starting to worry me.

 

Is it worth getting AC Lighting to come and look in your opinion?

[b1nuzz]

We had this problem not to long ago. We had a brand new 96 channels, 2 LD24's and 4 Act6 DMX Dimmers installed, and along the first 6 channels which were hard wired into the LD24, we had flikering.

 

We called stage LX out, who fitted the whole gaf, and they didnt really know what to do. Following this, we then had best part of 20/25 lamps blow within three weeks, and they werent having excessive use.

 

So we called them again, and theydecided it was probably a power problem.

 

The building is recieving power spikes which is causing the lamps to blow so that has to be sorted out, but we also reduced the LD24's to only pushing out the level at 80% even when the desk tells you its 100%.

 

This fixed the flickering problem, now we just need to get the spiking problem sorted out.

 

HTH

[Dweeks]

Nuts :)

 

Well I'm going to call AC Lighting in on Monday and see what they suggest.

 

Absolute nuisance though ;)

[dbuckley]

If you set all channels to 30% do all the channels flicker, and if so, do the channels flicker "together"?

 

Assuming the control is Ok, flickering usually means the dimmer is having difficulty latching onto the incomming mains waveform zero crossing, and the pattern of flicker can tell you a lot about where the fault lies... Problems are usually per channel (ie a duff channel) or per group in a dimmer (usually two out of six on six channel dimmers) or the whole dimmer, or all dimmers on a particular phase or supply, or just the lot.

[Dweeks]

I haven't run rigorous tests, but I think it only affects channels which are on 30%. So say 1,2,6,10 are at 100%, they will be fine. But channels 3,5 & 7 at 30% will flicker at the same rate. For example.

 

Thinking it could be related to the supply; the input is 32a, which I believe is the same supply as used for the old system which was about 50 years old...

 

I'm sure AC will sort it out. Hoping it won't cost a bomb though... it's a school, and they worked hard enough to get the system build in the first place!! ;)