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Author Topic: Dimmers with a neutral and Vera3  (Read 4702 times)

Offline TimAlls

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Dimmers with a neutral and Vera3
« on: December 16, 2011, 05:38:17 pm »
Hi All,
I have noticed that my Zwave communication really bogs down when a dimmer becomes disabled due to a burned out bulb. This is really a problem when only one light is on the circuit and the Zwave dimmer needs the load to provide power to itself.
Question: are there still dimmers on the market that have the neutral wire so that a no load situation have no impact on its abitlity to communicate?
Question 2: Is the Vera3 any better than theVera 2 on Zwave reliability?
Thanks
Tim Alls
AllSeas yachts

Offline TimAlls

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Re: Dimmers with a neutral and Vera3
« Reply #1 on: January 06, 2012, 09:57:44 pm »
Anyone know of a dimmer that has a neutral wire?......led lights do not pull enough current to power in line dimmers.....another issue.
Regards
Tim Alls

Offline nickrwym

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Re: Dimmers with a neutral and Vera3
« Reply #2 on: January 07, 2012, 04:16:55 am »
Anyone know of a dimmer that has a neutral wire?......led lights do not pull enough current to power in line dimmers.....another issue.
Regards
Tim Alls

Fibaro do a load module that goes across their dimmers if the load is less than 25W to overcome this problem.

I don't know if it works with other makes of dimmer

Nick

Offline garrettwp

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Re: Dimmers with a neutral and Vera3
« Reply #3 on: January 07, 2012, 08:03:35 am »
I believe fibaro is only EU and not US.

- Garrett

Offline nickrwym

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Re: Dimmers with a neutral and Vera3
« Reply #4 on: January 07, 2012, 10:11:36 am »
Tried to reply earlier but can't see it

You could put a small incandescent bulb in one of the fittings, 30W say and see if that makes it work. You still get the benefit of the LEDs in the rest of the lights on the circuit

Nick

Offline TimAlls

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Re: Dimmers with a neutral and Vera3
« Reply #5 on: January 07, 2012, 10:31:26 am »
I like the idea of a dummy load.....the extra light bulb idea would burn out and have to be hidden ..... So I will explore the dummy load.
Thanks for the response.
Regards
Tim

Offline rlmalisz

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Re: Dimmers with a neutral and Vera3
« Reply #6 on: January 07, 2012, 10:46:31 am »
I like the idea of a dummy load.....the extra light bulb idea would burn out and have to be hidden ..... So I will explore the dummy load.
Thanks for the response.
Regards
Tim

You can use the Leviton RZM-10 for incandescent.  It requires/uses a neutral.  They're optimized for magnetic/low-voltage, but from the manual (emphasis mine):

"Use with magnetic low-voltage transformers, incandescent, or 120V halogen fixtures only. Use a Leviton electronic low-voltage dimmer to control electronic (solid state) low-voltage transformers."

I use a few of them with incandescents (or LED incandescent work-a-likes) with no issue.   They say 40W minimum draw (like all the Leviton dimmers), but the one in this room is hooked to two Philips 12.5W Ambient LEDs, and works fine.  No flicker, no buzzing, nada.  It really looks like it's watt-draw below about 24W that makes these things slow to settle at a brightness.

They're not cheap, but this might be more attractive than a dummy load.

--Richard

Offline TimAlls

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Re: Dimmers with a neutral and Vera3
« Reply #7 on: January 07, 2012, 11:03:33 am »
Thanks Richard,
That is really what I am looking for. I figured someone must be using the neutral wire.....makes more sense than relying on the load.
Regards
Tim Alls

Offline nickrwym

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Re: Dimmers with a neutral and Vera3
« Reply #8 on: January 07, 2012, 11:47:07 am »
If you hide the "load lamp" you can under rate it to gain life, if you use a 240V bulb on 110V it will last for a lot of years.

The curves of lamp life vs voltage are very interesting. The gain in life from a small reduction in voltage is very impressive

Nick

Offline TimAlls

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Re: Dimmers with a neutral and Vera3
« Reply #9 on: January 07, 2012, 12:05:12 pm »
If you hide the "load lamp" you can under rate it to gain life, if you use a 240V bulb on 110V it will last for a lot of years.

The curves of lamp life vs voltage are very interesting. The gain in life from a small reduction in voltage is very impressive

Nick
Thanks Nick,
Interesting idea. I am curious as to how much heat a 5 watt resistor would generate.....one could play with the value to stabilize the circuit and be done with it. It probably doesn't need much to compensate for the Led electronic ballast. I will play with it and report back. If successful one could add this to all the single bulb controllers and never lose communication. A big plus in Zwave reliability since the mapping gets screwed up from the loss of even one dimmer.
Regards
Tim Alls
Allseas Yachts

Offline nickrwym

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Re: Dimmers with a neutral and Vera3
« Reply #10 on: January 07, 2012, 02:49:17 pm »
The heat depends on the value of the resistor and the volts across it, V squared / ohms is the formula

The wattage rating of the resistor needs to be greater than the wattage dissipated. Some resistors are rated to run very hot at their rated wattage, others need heat sinks to achieve the rated wattage.

If you use the lamp option then you can use two 110V lamps in series to under run things and make them last.

The dimmers tend to have a minimum wattage and you may need to bring your LEDs up to this figure, have a play and see what happens.

Nick

Offline autotoronto

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Re: Dimmers with a neutral and Vera3
« Reply #11 on: January 09, 2012, 12:49:12 pm »
Quote
I am curious as to how much heat a 5 watt resistor would generate
By definition, you can safely dissipate up to 5W in a 5W-rated resistor. The rating will take into account appropriate heatsinking and ventilation. If you put a 5W rated resistor in a small thermally insulated container and load it to 5W then it will likely overheat and melt or start a fire.

The thing about lamps is most of the energy is given out as heat, anyway. So if the device needs about 25W of incandescent load as ballast then it's going to need 25W however you dump that heat. There's not going to be any difference in heat output between a 25W lamp and a resistor correctly chosen to dissipate 25W, which will be roughly 550 ohms on a 110V supply, if my sums are right.