Dimmer module vs Relay units

Im trying to figure out the module count needed for my install. I'm leaning toward doing everything as a dimmer channel and just setting the min ramp time to act as a relay switch when needed.

Does anyone have advise for or against this method? Do inductive loads such as ventilation fans require a relay module?

 

As a general rule, the use of dimmers is primarily for lighting.

I think you answered the question yourself.

 

Hello poldim
If you know for sure there is going to be some non dimming fluro loads I would put them on a relay in the first place.

I have used the leading and trailing edge din rail dimmers for small exhaust fans without a problem.
It allows you to alter the fan speed if you want to adjust noise/air flow.
Check first with the fan manufacturer and make sure you set a minimum that is not going to burn the motor out.
I can't see any problem if you run an exhaust fan on full speed within the load rating of the dimmer.

The leakage Nick mentioned can cause regular CFL and various LED lamps to flicker even when the channel is off.
CFL lamps such as Philips Tornado Dimmable do not suffer from the off state leakage.
Some LED downlights also work very well.

In my opinion, when you are selecting the output units it pays to have some spare relay and dimmer channels.
It wouldn't hurt to leave at least 12 DIN modules spare in the board as well.
When calculating the space for dimmer modules I would work on the 4 channel units even if you use an 8 channel dimmer in case future loads require a change to the universal dimmer.

This will give you the ability to adapt to changing lamp technology without too much trouble.

 

In my system I had much the same philosophy of using dimmers over relays for future flexibility. The universals weren't available then. In practical usage a lot of my dimmer channels are now only used on/off and I have leakage issues with some loads. Softstart is pleasing though . So I am replacing dimmers with relays. A bit sad as it feels technically regressive and a waste of C-Bus capability.

Government policies regarding banning incadescents without replacements that are either affordable, better environmentally or technically capable forces this issue.

I bet there aren't many CFL's in the 10 Downing St. chandeliers.

K

 

If you ask the minister they will send you a reply.

 

Thanks for the advise. This somewhat curtails into my other thoughts of going with centrally located controls or splitting them up to some degree. Right now I'm leaning to having my electrical panelboard and then main clipsal panel (probably 36M or 60M depending on final count) in the first floor laundry room with one or possibly two distributed 24 DIN panels to eliminate long home runs.
Is a design like this typically used?
Are there things that would prevent this type of architecture?
Are there down sides other than having two panels?

 

Hi poldim
2 x 12 row board will only do 1 C-Bus din unit.
15 pole wide rows will leave some room for circuit protection.
I'm not sure how to advise you where and how many boards.
But in a home, once you have gone from floor to ceiling in the place where you imagined everything would fit.
Then you can safely say it's a good time to look for a sub board location.