Dimmer doesn't dim

Hello C-Bus Community!

I have an installation which includes 4 x 8 channel dimmer units ( cat 5508D1A, firmware version 1.3.0 ). 3 of these dimmers are fine, but 1 of them acts like a relay - the lights turn on or off when commanded by a switch set up to dim.

I have run the application logger and confirmed that the switching units are actually sending ramp to commands and not on / off commands. I have also been unable to see any differences in the configuration of the dimmers that dim, and the dimmer that doesn't.

Any ideas on what might cause this, or any direction on what else to check for would be appreciated.

Cheers
Steve Laidler
Ecosystems NZ

 

Steve

First things to do are disable all logic, clear the Area address (if used) and make sure your minimum and maximum thresholds are set to 0% and 100% respectively.

Check the Ramp 1 and Ramp 2 rates in your key unit(s). The units may be sending ramp commands well enough but the commands may be saying 'dim up and down instantly'.

What are your loads?

 

You may have tried this but check to make sure that the dimmer feed on the right hand side is on the same phase (ie red white or blue) as the left hand power supply side. If not the dimmer wont dim just switch.

 

Thanks Guys

Will check out your suggestions and let you / the C-Bus community know our findings. The loads are halogens, my feel is this side is OK as other dimmer units on the same job handle the same type of lights and dim OK, and also because I guess a problem with loading would show itself in a different way - i.e. the lights wouldn't come on at all or would cut out after a period of operation.

 

Problem solved!

Thanks again,

I am informed the problem was found to be as suggested, that the dimmer's supply and output circuits were supplied by different phases!

 

Is this really a problem?
I was hoping to run all the control from a UPS and selected Dimmer unit feeds
But reading the above this wouldn't work because the units would technically be on the different phases. ( UPS recreats the sine wave )
Mike

 

Hey Mike,

You could always just go and buy one of those 3-phase Uber-UPS's that can pretty much keep a whole house going for a day or so and run everything off one of those Should only cost you 10 or 20 thousand

(Sorry, couldn't help myself)

Darpa

 

Not a problem for the new "Universal" dimmer.

 

Its not as silly as it may sound .... it has been done before.

 

I know Tobex, lol

It's exactly what I would like to do for myself, because I'm fed up with mains power-supply issues, just haven't found a way to afford one yet

 

Thanks for the replies
Am I safe then feeding say two dimmers from the UPS, both dimmer and PSU supply and then feeding the rest of the dimmers from the incoming Mains? or should I only attempt this on dimmer units without Power supplies? I was worried about mixing the phase of the incoming Mains on PSU which were generationg the Cbus control voltage
thanks in adance
Mike

 

Stand-alone C-Bus power supplies can be run from any phase, or a combination of phases. This can also be a good idea because it gives you redundancy in case a phase "drops out".

As long as the dimmer inputs, and the control inputs on the top left side are on the same phase (or UPS), then you should be right.

 

Hmmm
I think I undertand
Doesnt this mean though that in the event of a Powercut only ca couple of PSU's would be trying to power the cbus control and therefore the control would be underpowered and to correct ths situation with full power there would be to much current capability on the bus?

Or am I overcomplicating this
Mike

 

Depending on your network's current requirements, as well as the number and type of power supplies, yes, your bus could be underpowered in the event of a blackout if not enough of your power supplies were plugged into your UPS.

Depending on the capacity of your UPS, if it has a high enough rating (VA) to handle everything you want to plug into it plus all of your "Stand-Alone" C-Bus power supplies, it would pay to connect all of them to your UPS as well as the dimmers that you wish to operate in the event of a power failure. But this is entirely dependant on the ability of your UPS to power everything required, both with full mains power, as well as on battery backup. You need to remember that most UPS's cannot have more equipment than they are rated to handle connected to them, and this inst just when on battery power, this is also when running from mains as well. You can quite happily connect some Power Supplies to mains, and some to the UPS, as long as you meet two conditions.
1: The total PSU supply current does not exceed 2000mA when all power supplies are operating (on mains and on battery)
2: That the PSU's that you have running from your UPS are enough to power the bus during a power failure

All of this advice is completely dependant on what equipment you currently have, as well as each piece of equipment's ratings (UPS, type of C-Bus power supplies, etc).

Hope this clears up your thoughts

Darpa

 

I saw one on ebay once with 2 tonnes of battery. It was around $900 + delivery which was around 2K.