2 switchlinc dimmers in tandem for high load...

[frustratednon-geek]

Does anyone know if I can tie 2 switchlinc dimmers together in tandem to allow for safe sharing of a dimmable load higher than 1000W?

 

I just burned up a new 1000W dual-band dimmer on 4 chandeliers at my church that I wanted to be included in scene control. Each chandelier has 5 x 60-watt bulbs (1200W total). Unfortunately they're up in the air about 15'+ and we only have 1 lead in the ceiling--splitting the load up isn't a realistic option. We really want dimming capability for this load.

 

My initial thought was to replace the drab, yellowish tungsten bulbs with 45W halogen clear bulbs. We'd get more light and use only 900W. The downside is everything's 15+ feet in the air and we don't have a tall enough ladder... Also, I'm not wild about running this dimmer at 90% of rated capacity all the time.

 

Another thought would be to tie the loads together from 2 x 1000W switchlinc dimmers and syncrhonize them with the same on-level & ramp rates in all scenes. In theory wouldn't this split the load among the 2 devices?

 

Maybe a cleaner approach would be a hybrid with a 20A Switchlinc relay for full-bright main on and then configure a scene that shuts the relay off and simultaneously ramps the 1000w dimmer to something <80%... Are there any known/obvious problems with 2 switchlincs being wired in tandem to control the same load?

 

Thanks in advance!

[LeeG]

Two dimmers cannot be connected in tandem. I also agree that running them at 90% of rating is pushing the limit. The dimmer would have to be in a box by itself. Putting the dimmer along side of another dimmer derates the dimmer plus it is often necessary to remove some of the heat sync fins which also derates the dimmer.

[oberkc]

How about an inlinelinc at each fixture? I am not sure that you are going to be able to avoid climbing the ladder.

 

I have heard of folks around here who use a relay, controlling the relay with an IOLinc, but that would be for others to provide any details.

[apostolakisl]

I agree. I think you need to go up the ladder. If you have incandescent bulbs, you will need to head up there anyway every 2000 hours of use.

 

I don't think you can switch to led. I have never seen a chandallier bulb that is more than 25 watt equivalent (3 watts). Maybe I'm not looking in the right place.

 

Putting an in-line linc at one or more of the chandalliers is the only option I can see. Or using 45 watt incandescents instead of 60.

[ELA]

What is the actual wattage rating of the In-linelinc?

 

The Manual says 300watts. It refers you to the Smarthome ad page for specifications.

 

Looking up above on the ad page it says 400watts , under specifications it says Max Amps 2.5 , Max Load 400watts.

 

if ... 2.5 A x 120 V = 300 watts

 

This is then confusing. What is a person to expect?

[oberkc]

Looking up above on the ad page it says 400watts , under specifications it says Max Amps 2.5 , Max Load 400watts.

 

if ... 2.5 A x 120 V = 300 watts

 

This is then confusing. What is a person to expect?

 

Agreed. This seems a little strange.

[apostolakisl]

It could be the type of load. Resistance vs Inductance. Usually wattage is listed for resistance loads and amps or volt-amps for inductance.

 

They may also be hedging a little on the wattage since they assume an in-line linc is going to be in a sealed up space.

[oberkc]

It could be the type of load. Resistance vs Inductance.

 

I thought the same thing...except that it is "rated" for incandescent lamps only. Pure resistance. No power factors.

[Brian H]

Incandescent bulbs when first turned on produces a surge current until the filament in the bulb warms up.

You frequently see a pure resistive and incandescent bulb rating a different value.

[oberkc]

Incandescent bulbs when first turned on produces a surge current until the filament in the bulb warms up.

You frequently see a pure resistive and incandescent bulb rating a different value.

 

But still, it is rated for incandescent loads, 120V, 400watts, 2.5 amps. Unless you are suggesting that one is a transient rating and another is steady state, there appears to me to be an inconsistency here.

[Brian H]

No suggestions. Math error somewhere on Smarthome/Smartlabs specifications.

My point was you frequently see a different wattage rating for pure resistive loads like hearers and incandescent type bulbs.

[frustratednon-geek]

Everybody keeps talking about these 'fins' that you can break off on the high wattage swd's but I just bought the new dual-band 2477DH and I don't see any fins, just a metal chassis on the sides:

 

Also, the dual-band housing doesn't seem deeper like they show on the website. While I admire how they managed to shove it all in there, I really don't need this thing blacking out on any given Sunday. I'm pretty sure I'd cuss out loud in that scenario...

 

So I slept on it and I think the right solution--at least for now--is to control the heavy load with a 20-Amp KPL relay. The 4 chandeliers in question are always on full-bright anyway and I've got 2 in the back that are on a separate switch for scene manipulation:

 

The LED up-lights + 2 rear chandeliers should be a nice effect once it's all in (PS they don't look that green in person):

[frustratednon-geek]

I'm not gonna lie; I'm a little bummed about not being able to ramp between scenes on those 4 chandeliers... maybe someday Insteon will make a 20-amp dimmer for commercial app's. They could use 2 gangs for cooling if necessary... space is not the issue in this case:

 

The 20 amp KPL relay I'm reallocating for the 4 chandeliers was intended for the LED driver for the up-light strip(s). I projected a total load of <400 watts:

There are 4 x 16' LED strips at 8A per roll

8A x 12V = 384 watts correct? Man are those suckers BRIGHT compared to incandescent ropes that use 10x as much pwr...

 

Only $65.00 per roll on ebay: Warm White 600 SMD LED Ribbon

 

I only ordered enough LED strip for the sides but if it turns out like I think it will I'd like to fill in the back wall with LED tape for maximum ambient light:

[LeeG]

frustratednon-geek

 

SmartLabs has a Pro line of Insteon devices that are available only to a Professional Insteon Installer. Perhaps a Pro installer will have access to a dimmer with higher capacity. Would take the project out of the DIY category.

 

Lee

[apostolakisl]

Two things:

 

1) The "fins" are the extensions of alluminum at the top and bottom that extend out further than the width of the plastic housing. They can be snapped off if you are putting multiple switches next to each other, but that reduces the heat sink.

 

2) The chandalliers you have are different than I thought. I was thinking the small bare-bulb ones with the small base. I think your bulbs may have the full size base (a19). Plus, they look like they are hidden by a decorative glass piece. My point being, if indeed this is the case, you should definitely think about going with LED. You can get 60 watt eq in those bulbs that only use about 10. Insteon works just great with every led bulb I have ever tried and LED's usually dim pretty well. Make sure you get 2700k bulbs, however.

[IndyMike]

Hello frustratednon-geek,

 

Since this is a commercial installation, please proceed carefully. The switch rating should be matched (exceed) to the maximum fixture load. The rated fixture load may well exceed the 60W bulbs that are currently installed. If you "trust" the original dimmer installation (1800W) do not install a device with a lower rating. If you are unsure about the installation, look up the max fixture rating or get out that ladder (that you don't yet have).

 

I was not aware that SH was offering a 20A KPL. From the website, it lists a 1800W incandescent capacity. Again, please be careful and check the UL label on the back of the switch. I have switches that are rated differently from the information presented on the website/product manuals. An inspector will not care about websites or manuals - he will look at the UL label which indicates what the device was certified to.

[frustratednon-geek]

IndyMike: Thanks for the great advice. I just got off the phone with my dad who was chief engineer/director in a hospital for 20 years and he basically said the same thing about wattage and leaving at least a 30% buffer for line voltage variations, increased cold-start amps, etc.

 

 

Duly noted on the 1800W incandescent load for the

20Amp heavy duty KPL relay. I knew inductive loads were different but didn't realize incandescent loads had to be up-rated like that as well.

 

apostolakisl: I think LEDs are in our future (as in <2000 hours future!) but we've got a couple problems to overcome:

1. Cost: we just acquired the property and finished a huge reno so it would be near impossible to justify spending ~$1000 to re-lamp especially if the result ends up being less bright overall.

2. LED-itis: 2 people told me they liked the warmth of incandescent and that LED's are too cold. When I showed the LED test-strip (2800k) to one of the gals who had told me she didn't like LEDs, she couldn't believe it.

 

I know it's the best solution from a technical standpoint but we need the 100W equivalent bulbs to get ironed out I just read about the Switch Lighting's "World's first 100 watt equivalent LED bulb." I bet 5 of those suckers per chandelier would be plenty bright as long as they get the Kelvin warm enough.

 

I think the solution for now is to let the heavy-duty KPL Relay handle the load (1200 load/1800cap = 66%, okay dad??) and then just live without dimming those 4 for now. Down the road we could either migrate to LEDs and/or I'll just hit up my contractor buddy for a ProLine dimmer (and professional installation of course). Thanks for your help guys!

[IndyMike]

frustratednon-geek,

 

Knowledgeable Fathers are a wonderful thing to have. I still consult my Father on electrical issues (he's in his mid 80's now). Spent 30 years in Aerospace and, as luck would have it, 10 years as Chief Engineer in a local Hospital. I have 30+ years in Aerospace, but I still listen and learn.

 

I'm still a bit concerned about your fixture ratings - the switch must be rated for the fixture, not the installed bulbs. If your fixtures are rated for 60W bulbs, an 1800W switch is appropriate. If the fixture is rated for 90 or 100W bulbs you are at or over the switch rating.

 

My chandeliers are rated for 6-100W bulbs (I have 60W installed). Even though my installed load is 360W, I use 1000W dimmers because that is what the fixture demands. Check yours to make sure. If the worst happens, you want to make sure that an insurance adjuster does not point to this switch.

[gatchel]

I also think LED bulbs will be a good fit here. If you live in certian areas you can get LED 60 watt replacement bulbs for $10 to $15 at the big box stores. The actual draw is like 10 or 12 watts.

[frustratednon-geek]

Another great point IndyMike. Something about re-lamping to a lower wattage controller like that seems half-baked. What happens 5 years from now when someone who has a thing against LEDs decides to switch back to 100W incandescents... I talked to Pastor Jim yesterday and he specifically remembered buying them because they were rated 100W/lamp. He said the electrician put the 60W bulbs in but wasn't sure why... I think I know why!

 

There was some scrambling when we acquired the building and took on an extensive Reno. Code enforcement called out some asbestos removal in parts of the main ceiling that had been torn into. The electrician wanted to split up the front 4 chand's but it meant runnign the risk of additional asbestos removal... It's all making a little mroe sense now!

 

I think the correct fix here for a dimmable load will be ProLine. I hit up my contractor neighbor today and he was really interested in the technology. Does anyone know if the ProLine devices are cross compatable with the rest of the Insteon line?

[Brian H]

The Pro Line modules should be compatibale. Many of them are the same modules with different part numbers. Starting with a 47??

 

Though a few modules are Pro only. Like a Active power line coupler for phase coupling.

http://www.smartproline.com/4700.html

 

Central Controller.

http://www.smartproline.com/4706.html

 

http://www.smartproline.com/products.html

[ELA]

Thanks Brian,

 

You provide such great links all the time!

 

I thought your link cleared up my question about In-LineLinc Dimmer ratings.

On the pro model they make clear that the 2.5A rating is for incandescent. So they are only good for 300W of Incandescent lighting load. That seems pretty wimpy for a Pro model?

This prompted me to look at the Insteon floodlights to see if they stated a maximum bulb size. All I found was this (using the standard In-LineLinc):

" Controls all standard incandescent and inductive loads, up to 480 watts"

 

Now I am confused again

 

Do people run the floodlights with (2) 150W par38 type bulbs and have good reliability or lifespan? What about derating and not running a device to the maximum capability (if they are truly rated at 300W incandescent).

 

I didn't see a dimmer greater than 1000W?

 

I found that exposure to the pro line interesting but I would have hoped for increased ratings? What then is the advantage of the pro-line?

[frustratednon-geek]

The rest of my Insteon order came in today along with the 4 addt'l rolls of LED strip for up-lighting of the Cove.

 

I decided to use the 20Amp 6-KPL Relay to control the 4-chandeliers x 5 bulbs load. It's got an 1800W rating against a <1200W load so plenty of extra capacity. My plan is to run the Load (red) from the KPL relay through the existing Lutron slide-dimmer on its way out to the lights. Insteon will only be able to flip the switch on or off but the on-level (so to speak) could be set by the manual slide dimmer.

 

I don't see any problems with doing this, anyone else? No problems with cooling--slide dimmer is in separate box by itself.

[oberkc]

anyone else?

 

No problems in my mind. I have been considering doing the same thing for some ceiling fans.

[gatchel]

frustratednon-geek

 

SmartLabs has a Pro line of Insteon devices that are available only to a Professional Insteon Installer. Perhaps a Pro installer will have access to a dimmer with higher capacity. Would take the project out of the DIY category.

 

Lee

 

Completely off topic but, How does a higher rating of a dimmer take the project out of a "DIY" category. Are there some special secret wires that only the pro's know about?