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sparkyparky

Hi Guys,

Hope you're all enjoying a rare bit of decent weather (it is in the midlands at any rate), came across one of these at a hotel, it's controlling a rake of LV spotlights in tandem with a dimmer switch but it's packed up.

Live feed comes from the board, through the dimmer then into the pictured unit (top left connections) then out and onto the switch wire for the spots. The two connections on the right (5+6) go to the other side of the dimmer switch I'm assuming they're to control the unit itself. All connections are in an AD box just out of shot, it's definitely the unit as I've connected the spots in question onto one of the others that's working.

There's no manufacturer labled on it or the switches and google brings up nothing for that model number, I'm assuming it's some sort of inductive dimmer control as it's in VA but I've never seen one myself before, anyone ever seen one of these or know of something that will do the same job? Any help or advice would be greatly appreciated!
 

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They look like just 1kW dimmable power supplies, I assume the output is 12V or 24V, if the dimmer comes in first then this is presumably not how they were originally designed, it looks like they should have been dimming the output not the input.
 
Hi mate thanks for the reply. The input and output are both 230v which is what was throwing me as the dimmer switches can't be more than 400w rated and there's about 12 spots on each, thinking about it though they might only be 20w lamps and this is just some ancient way of dimming 12v transformers, I'll check a few when I go back. If that is the case I'll just do away with that old thing and put a standard 400w trailing edge dimmer and if it's not it must be some kind of sorcery, thanks again!
 
Looking at the design the intent would be to have a power supply coming in on 1 and 2 then a dimmer (potentiometer) would be connected on 5 and 6 that would then control the output power to the outgoing supply on 3 and 4.

So based on this I would ask where do the black and red wires go when they leave 5 and 6?
Because they should go to a dimmer but you have said that the dimmer is connected on the top left of the unit.
If there is nothing connected to 5 and 6 then the units do appear redundant, unless the lamps are not dimmable lamps and are being dimmed by a particular control method from these units, but this seems unlikely as the units would not be actually doing anything without control from 5 and 6
 
Yeah that's the weird thing the dimmer switches have 2 terminals at the top and 2 at the bottom. A 240v live in and out on their bottom 2 terminals (from the board to connection no.1 on the unit) then connections 5 + 6 on the unit go to the dimmer on its top two terminals which doesn't make a lot of sense to me
 
is it similat in operation to a fluorescent ballast dimmer where the pot. supplies a variable elv voltage to the ballast?
 
It makes sense to me. The circuit perm L goes through the switch part of the rotary control (bottom terminals), from which the SL goes to terminal 1 on the remote module in the picture. This module contains the dimmer circuit itself, which is hard fired (i.e. leading edge inductive rated) and needs the neutral to function, hence the neutral going through 2 & 3. The dimmed L output is on terminal 4. The module sends a separate circuit out of 5 & 6, which might or might not be ELV, back to the potentiometer part of the control (top terminals) to sense the knob position.

It is as though the electronics of a twist dimmer have been wrenched off the back of the switched pot and extended away on wires, two for the switch and two for the pot.
 
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Ahh right that makes a bit more sense thank you much appreciated, so as the full circuit load will be going across the switch and it's definitely not bigger then a 400w then they must be 20w lamps its feeding I will double check when I'm back there next week.
So my next question if you don't mind (and I think it might be a no lol) is, is there anything out there that you think I could use to do the same job or is it just some weird obsolete system someones dreamt up? They must be at least 20 years old
 
See if you can get an all-in-one dimmer that meets the spec of the lighting load. Then just abandon the leads on 5 & 6 and link 1 & 2 to 4 & 3. Or if you can't get one beefy enough, use a 1-10V system as Tel mentioned.
 

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