[jabriel]

Hi,

I am about to wire a small cinema room with either 4 or 6 circuits for the lighting solution. I need some guidance as to what would be the best products for me. (I'll be purchasing dimmable LEDs to use throughout all circuits.)

If I opt for 4 circuits, the configuration would be as follows:
Circuit 1 - 4 x 5W LED
Circuit 2 - 3 x 5W LED
Circuit 3 - 3 x 5W LED
Circuit 4 - Either 6 x 5W LED or 8 x 5W LED

If I opt for 6 circuits, the configuration would be as follows:
Circuit 1 - 4 x 5W LED
Circuit 2 - 2 x 5W LED
Circuit 3 - 1 x 5W LED
Circuit 4 - 3 x 5W LED
Circuit 5 - Either 4 x 5W LED or 6 x 5W LED
Circuit 6 - 2 x 5W LED

At the moment I am leaning towards a Lutron Grafik Eye QS solution. I like the look of it and as far as I know, if set up correctly, they work pretty well. (The astronomic time clock is a welcome bonus.) I don't mind considering other brands but would need someone to recommend what equipment I should consider.

Based on what little I know, my current concerns with the Grafik Eye QS are:

1. Will the load I have on each circuit be sufficient or will I have to buy the Lutron Synthetic Load?

2. Assuming I have to buy the Synthetic load, would I need only one or would I need one for each circuit (below 40W or whatever the threshold is)?

3. What is the min load any circuit would need so one does not need to purchase the Synthetic Load? (I may be able to reconfigure the circuits or buy bulbs which are maybe 6w or 7w - If that helps?)

4. If I buy the Grafic Eye QS, do I need to buy anything else other than the bulbs, fixtures and wiring?

5. Will any dimmable LED bulb work with the Grafik Eye
As you can tell I'm pretty new to all this so be gentle...

Thanks in advance.

[compolitus]

Hi

Have you also looked at the Futronix P400 dimmer?

It is capable of dimming some led's without having to use any additional load (which defeats the whole object of using led's).

Have a look on their web site at Futronix Dimmers - Large innovative range of dimmers, switch plates, switch panels, lighting controls, home automation or contact their technical team at technical@futronix.com for helpful advice.

What type of led's are you proposing to use, GU10 spots Par30/38's etc as I may be able to recommend a supplier ?

Any questions please ask.

Hope this helps

Compolitushttp://www.avforums.com/forums/images/smilies/smile.gif

[LightBrigade]

The Grafik Eye QS is a lot more than a dimmer, which is why its a great solution. But, I think the minimum load per circuit is about 50W. Best to check this though - maybe just call Lutron and ask them.

If it is, adding a synth load per circuit completely defeats any energy saving benefits - you will be burning hundreds of watts instead of 10s of watts. You could use relays and contact closures, but its a little messy and more hassle.

[jabriel]

Thanks for your replies folks.

I ended up purchasing the GEQS. Its a 6 zone model and is configured as follows:

Total watts in Zone 1: 3 x Toshaiba 8.5w lamps = 25.5w

Total watts in Zone 2: 3 x Toshaiba 8.5w lamps = 25.5w

Total watts in Zone 3: 3 x Toshaiba 8.5w lamps = 25.5w

Total watts in Zone 4: 6 x Toshaiba 8.5w lamps = 51w.

Total watts in Zone 5: 2 x Toshaiba 8.5w lamps = 17w

Total watts in Zone 6: This will be a regular lamp so I can ensure I purchase a 40-50w bulb so no problems here.

All lamps are GU10.

Naturally not all zones will be lit all the time. I'm guessing I'll most likely use 2 out of zones 1, 2 and 3 at any one point. Zone 4 will most likely be used at the same time.

Zones 5 and 6 will be used least often.

Out of memory, when I spoke to Lutron about a month or so ago, they mentioned each zone needs a minimum of 40w.

I've asked my the electrical supplier I'm using if they are able to supply synthetic loads which are cheaper than the Lutron range or loads with watts that match my specific requirements so I don't end up using 100s of watts. (I.e. Zones 1,2, and 3 to use a synthetic load of 14.5w or as close to this as possible. Zone 5 with a 23w synthetic load or as close to this as possible.)

Your thoughts?

LightBrigade, can you send me links to the types of products you recommend?

Thanks in advance.

[compolitus]

Hi

Good luck with your Lutron purchase.

Just remember to buy compatible led's to get the best out of the dimming.

Not sure what wattage values are available for the dummy loads but ensure they are suitable for the installation position as they will get hot.

The other option is to use a couple of standard GU10 filament lamps in the chain to act as the load. This way you do not waste all the energy and still get some light. Dummy loads may be more expensive than the lamps!!

Looking forward to hearing about your final installation.

[jabriel]

Hi again,

Dispite emails from Lutron's technical support teams, telephone conversations with the same and messages from others confirming the min load requirement for each zone is 40w, somehow, I have managed to get everything working 100% without meeting this requirement.

Each zone was set up as per my previous post and I used the Toshiba 8.5w lamps. (Lutron confirmed they have tested these and they work but the 40w min load was still a condition that had to be met.) Each zone set up works perfectly without having to use relays, synthetic loads, hidden lamps or anything else.

I'm not sure why Lutron suggest the min load requirement is 40w per zone?

Unfortunately, the area where I was expecting no issues proved to be the biggest neuroscience.

For some other rooms, I purchased Lutron Rania dimmer switches. I'm using the same lamps but find that the lamps flash. (This happens regardless of if I try to turn the lamps to 100% or at any other brightness level.)

I switched dimmers to ensure it wasn't a case of a faulty dimmer but that didn't make any difference.

The dimmer switches can manage up to 450w but I'm not exceeding much more than 250w.

The temporary solution I stumbled across was to add a halogen lamp to each circuit. Doing this allows me to brighten each circuit up to 50% without the flashing occurring. If I try to go any higher than 50%, the lamps start flashing again.

I'm completely lost with what would cause this. (That said, I'm not terribly technically minded either so perhaps there is an easy inexpensive fix?)

Any help offered will be much appreciated.

[vex]

On the Rania dimmers I think you can change the settings through a series of button presses.

From memory, With these changes you set the dimmer to a trailing edge which should make them dim better.

If you can get the details from Lutron, great, if not then let me know and I'll see of I have it or can get it for you.

V.

[LightingControl]

Do you have 250w of the LEDs on the Rania?

With phase dimmable LEDs you need to derate lutron dimmers by a factor of 10. 450w rania dimmer will only cope with 45w of LED. It may work with slightly more than this but it may cause premature failure of the unit. To cope with 250w of LED I would try a power booster.

When you say the LEDs flash what do the LEDs on the front of the Rania do? If the LEDs on the Rania flash exactly what LEDs are flashing?

Reason for the derating is the large inrush currents from LEDs and also the current spikes created from dimming phase dimmable LEDs.

One thing you could try that has worked for me before is to force the Rania into leading edge dimming. This can be done by button presses.

Cheers

[jabriel]

Thanks for the feedback.

I was slightly misinformed when posting my previous message. Since then I've learnt I should be using the equivalent incandescent load for calculating the wattage of the lamps. I was previously using the 8.5w detailed on the Toshiba packaging instead of the actual incandescent load. (I'm new to this arena hence the error!)

Having worked out the equivalent incandescent load (50w/lamp) I now realise I cannot have more than 9 lamps on any one circuit. (I need 16 lamps per circuit!) The workaround Lutron suggested is to buy a power booster. I'm happy to do so unless someone can suggest a cheaper solution which is tried and tested. (Reducing the number of lamps used isn't an option unfortunately.)

Additionally, I have also now changed the setting to trailing edge and set bleep mode on. This addressed the issue I had with lamps flashing. (Thanks again for the tips.)

Does anyone know where I can get source the power boosters at a reasonable price? Or are there substitute products that have been tested and work 100%?