8 Ch Dimmer Unit

I''m completing a new installation with 5 x 8ch dimmer and 8 x 12 ch relays, on commissioning I have noticed on one 8ch dimmer the loads don't dim correctly ie on the horizontal scale of the DLT it has just started to move up and the load is very brightly lit, I have tried the same load on a differently installed dimmer (that was working) and all is good, I have also tried dumping the program from the dimmer that is not working correctly to one that is this all worked fine, lastley I went and bought a new dimmer (thinking the one I had is faulty) still the same results not dimming correctly, I have exhausted every avenue I'm thinking a second faulty dimmer anyone any thoughts or have experienced the same problems

 

some Low Voltage down lights throught osram redback trannys and some bi-pin halogens using a atco iron core tranny

 

Are both the A/L connections on the dimmer fed from the same phase?

Michael

 

If the DLT is having trouble communicating, it may be the case that the slider doesn't actually represent what's happening on the network.

I'd use Toolkit or Diagnostic Utility to set the level of the group for the troublesome channel to 50%. Then, look at the brightness of the load and the slider position on the DLT. Then try 25% and 75%. If they all seem about right then I'd suggest you have a comms issue.

Make sure you also check the minimum and maximum brightness settings for the dimmer. If the minimum setting is high, say 80%, then as soon as the group address turns on at it's minimum value, the output of the dimmer will be 80%. If you're not sure how the dimmer should be programmed, use Toolkit to set it back to it's default settings, then put the channel groups back in, leaving everything else set to the default.

 

We were called out to a similar problem to this a few weeks ago,
The sparky had accidentally mixed the neutrals

The DLT level indicator was showing the load dimming when it wasn't.

Just a thought, But I just program, none of the electrical side

 

I really appreciate all your help out there, sorted the problem out (Thanks MJS) the problem is we ran 1 x c-bus control circuit to all the output units control terminals, being a 3 phase installation we have some properly working dimmers and some not hence balacing the load we have some on the same phase as the control circuit and some not, all the ones on the different phase are not working correctly. We changed the control circuit to the same phase as the dimmer and all is good now, a trap for young players. Once again thanks MJS.

 

Glad you got sorted. I was also caught once with the same problem.

Michael