Re: LED dimmable bulbs with X10 switches

["Bob F" <bobnospam@xxxxxxxxx>]

Geoff wrote:
> On Sat, 21 Feb 2015 11:03:33 -0800, "Bob F" <bobnospam@xxxxxxxxx>
> wrote:
>
>> Bob F wrote:
>>> I just bought some Cree LED soft white "60W" "4FLOW filamant design"
>>> bulbs.
>>> On one circuit, with just one bulb, the bulb lights at a mid level
>>> when off or full brightness when switched on at the switch. The
>>> switches involved are the old X10 switches with a lower section that
>>> slides to the left to cut off all power. The problem is that the X10
>>> controller cannot turn that bulb either on or off. Turning other
>>> circuits using the same controller continues to work fine.
>>> On another circuit, there is a 2 bulb fixture downstairs and a 2
>>> bulb fixture upstairs, all currently incandescent bulbs. If I
>>> remove one of the incandescent bulbs downstairs and replace it with
>>> the LED bulb, everything works OK, with the incandescent bulbs
>>> dimming much more than the LED bulb when the dimming function is
>>> used. When I removed the downstairs incandescent bulb,leaving the
>>> LED bulb, again I could not control the lights with the X10
>>> controller. This is despite the 2 incandescent bulbs in the
>>> upstairs fixture.
>>> Has anyone here seen similar problems, and come up with any
>>> solutions to them?
>>> I do realize that the low brightness issue in the off position of
>>> the initial circuit is do to the switch sense feature of the X10
>>> switches, and that the incandescent bulbs in the second circuit
>>> eliminate that problem there.
>>
>> I just tried the second circuit again, and it seems I can turn in
>> off with the controller, but not on.
>>
>
> You are dealing with a limitation in the triacs in the X10 that switch
> the current to the load on and off. There is a minimum sustaining
> current that a triac needs to keep itself on after it's been fired by
> the trigger circuit. Replacing an incandescent with an LED can put you
> below that minimum current and cause the triac in the X10 module to
> turn itself off.
>
> The load required by an X10 dimmer varies with the manufacturer but
> what I've found during a quick google search is a 40W minimum might be
> typical. At 120VAC this means the minimum load current needs to be
> around 0.33 Amps.
>
> With LED technology you need to ignore the "wattage" of the bulb since
> it's an equivalent rating, not a power consumption rating. A Cree 60W
> equivalent bulb uses only 9 to 9.5 Watts in the soft-white and
> daylight types and that's less than 0.08 Amps at 120 volts, a very
> economical current indeed and about 4 times less current than a 40W
> incandescent will draw.
>
> If it's a multi-bulb fixture you can add three more LED bulbs to get
> the total current up into the sustaining range of the X10 but it may
> be more economical to use an appliance module instead. It uses a relay
> and you lose the dimming capability and the "all lights on" capability
> but if remote on-off is your desire then it's definitely preferable to
> loading up on LED's just to get back into the higher current draw that
> LED's are supposed to be avoiding.
>
> P.S. I love my Cree LED bulbs and I've made it my goal to replace all
> my incandescents with Cree bulbs as the incandescents burn out.

The switch at the wall has no trouble turning them on and off. It's only the
remote control that has the problem, which would make me think it's a
communication problem rather than a triac holding voltage problem.

I did just go try the bulb in another lamp controlled by an appliance module.
Interestingly, this bulb did not glow when off like the other LED bulb that had
been in that lamp. It also switched on/off remotely just fine.

Wierdness!