Dimmer that won't switch off

[dth122]

I have a HA system that has worked well for 5+ years, but suddenly developed a strange problem. The general architecture of the system is a CM11A that sends commands throughout the house, with a Leviton coupler/repeater at the panel. The problem I have is that one of my Leviton 6381 dimmers suddenly stopped responding to any commands after it's turned on. It turns on fine, but any off or dim settings are ignored. I swapped out the dimmer for a known working one, but that didn't help. It's in a 2-gang box with another 6381 that works perfectly. They both share the same hot, neutral and ground - only the load is different. I even tried replacing the light bulbs connected to the dimmer with the problem, but that didn't help.

Interestingly, when I use a TM751 on the same circuit as the problem dimmer, it works OK with a PalmPad but continues not to work with the CM11A. However, when the TM751 is plugged in, the adjacent dimmer in the 2-gang box also stops responding to OFF commands.

I can't think of any recent additions or changes to the in-house wiring that could be causing any noise or other problems.

Any thoughts on what could be at play or other troubleshooting steps?
- Dave

 

[IndyMike]

I have a HA system that has worked well for 5+ years, but suddenly developed a strange problem. The general architecture of the system is a CM11A that sends commands throughout the house, with a Leviton coupler/repeater at the panel. The problem I have is that one of my Leviton 6381 dimmers suddenly stopped responding to any commands after it's turned on. It turns on fine, but any off or dim settings are ignored. I swapped out the dimmer for a known working one, but that didn't help. It's in a 2-gang box with another 6381 that works perfectly. They both share the same hot, neutral and ground - only the load is different. I even tried replacing the light bulbs connected to the dimmer with the problem, but that didn't help.

Interestingly, when I use a TM751 on the same circuit as the problem dimmer, it works OK with a PalmPad but continues not to work with the CM11A. However, when the TM751 is plugged in, the adjacent dimmer in the 2-gang box also stops responding to OFF commands.

I can't think of any recent additions or changes to the in-house wiring that could be causing any noise or other problems.

Any thoughts on what could be at play or other troubleshooting steps?
- Dave

Hello Dave,

All dimmers produce impulse noise even when connected to incandescent lighting (I'm assuming you're using incandescent and not dimmable CFL's). The fact that adding a TM751 to the circuit makes both unit fail to respond to and "Off" command makes me believe you are very marginal on signal level.

If you would like to verify that it is a signal level problem (not a command problem) you could move your CM11 to the TM751 location. If that works, I'd suggest that you have a new signal absorber between the affected units and the panel (between them and your HCA02).

If you can identify the offending load, filter it with a X10 or SH filter. If you cannot, or you have other "problem areas" you have a number of options:
A) Purchase an X10 signal analyzer and trace down absorption/noise sources.
B) Replace your existing repeater with a high output version to increase the signal strength.

For both of the items above, I would refer you to Jeff Volp. He has designed a number of repeaters as well as an X10 analyzer that are second to none (in my opinion). These are available in both Kit and completed forms. I am currently using one of his XTBR plug in units in my 4500 sq foot home (mixed X10 and Insteon) and it has breathed life back into my X10 components. I previously used a Leviton HCA02.

Jeff's home page can be found here: Jeff Volp XTB

IM

 

[KeepItSimpleStupid]

What kind of load? CFL lamp? Did you change the type of load and did it work?

I might suggest an RFI filter before the load. If you have a surge suppressor with an RFI filter like the Isobar try that at the load, but after the dimmer.
I beive there is a specific filter that's available for X-10 systems that may work too. I know there is an expensive wired one, for that's the solution for part 2 of my post.

Did, by chance did you have a new furnace installed with a variable speed blower? Solution is similar, but different in this case.

 

[dth122]

The log in a single incandescent light. It's hardwired to a fixture in the ceiling, so there's not much I can do to change it or add filtering without digging into the ceiling. I can't imagine that's the problem though.

Good call on the furnace. Yes - I did have one installed, but it was 2 years ago and I already have a filter on it.

The CM11A is attached to a semi-permanent enclosure so I couldn't easily move it, but I did the opposite... I put the TM751 where the CM11A is. It seemed to perform better, but still not flawlessly.

It's funny that you mention Jeff. I found his website a few days ago when I first started seeing problems. I have both an analyzer and repeater on order. I'm glad to hear that you success with his products. Hopefully I'll have the same experience.

In the meantime, I'm still baffled by what caused my problem to appear in the first place.
- Dave

 

[KeepItSimpleStupid]

The furnace issue would only manifest itself when the blower is on.

Your coupler could be bad. I doubt that an incadesent load would be the issue. Can you check which side of the coupler he two circuits are?

 

[BLH]

My furnace has electronic ignition. It only runs for the first thirty seconds after starting. It makes power line noise that can make one of my Insteon Modules miss a command.

Jeff's devices are nice. I have the XTB-IIR myself. Elk ESM1 meter shows my weakest outlet is four bars. Insteon module when using their X10 primary Addresses I added for some of my old X10 remotes and other modules with no Insteon equivalent.

 

[KeepItSimpleStupid]

My furnace has electronic ignition. It only runs for the first thirty seconds after starting. It makes power line noise that can make one of my Insteon Modules miss a command.

Jeff's devices are nice. I have the XTB-IIR myself. Elk ESM1 meter shows my weakest outlet is four bars. Insteon module when using their X10 primary Addresses I added for some of my old X10 remotes and other modules with no Insteon equivalent.

I had a problem anytime the fan ran. In other words the the Electronic Commutated Motor was causing the problem.

 

[IndyMike]

The log in a single incandescent light. It's hardwired to a fixture in the ceiling, so there's not much I can do to change it or add filtering without digging into the ceiling. I can't imagine that's the problem though.

Good call on the furnace. Yes - I did have one installed, but it was 2 years ago and I already have a filter on it.

The CM11A is attached to a semi-permanent enclosure so I couldn't easily move it, but I did the opposite... I put the TM751 where the CM11A is. It seemed to perform better, but still not flawlessly.

It's funny that you mention Jeff. I found his website a few days ago when I first started seeing problems. I have both an analyzer and repeater on order. I'm glad to hear that you success with his products. Hopefully I'll have the same experience.

In the meantime, I'm still baffled by what caused my problem to appear in the first place.
- Dave

Unfortunately, your problems are likely not due to a single device. A single offender will typically take down your X10 system immediately and is therefor easier to detect. You've more likely been slowly adding signal absorbers/noise makers until the system S/N ratio is marginal. The analyzer will be able to quantify this. Jeff's amplifier (32 to 40 Vp-p vs the 5 Vp-p from the Leviton) should make the problem devices a non-issue.

Jeff is an extremely knowledgeable and interesting guy. I ran some Beta tests for him on the XTBR using my combined Insteon/X10 system. He worked hard to ensure there were no compatibility problems between the two protocols. I'm not sure what he did in his past life, but I'm really happy to have him designing HA equipment now.

IM

 

[pkoslow]

Jeff's home page can be found here: Jeff Volp XTB

IM,

Interesting site and products...

I'm meeting my electrician tomorrow to install an ACT CR234 which I've used successfully in the past for marginal X10 installations, but might have tried Jeff's product had I known about it.
http://www.act-solutions.com/PCC/pdfs/PCCS.../cr234_spec.pdf

This customer has a Leviton coupler/repeater installed, but signal strength is only 200-300mv in most areas of the home.

To the original poster, you really do need some type of X10 analyzer to help troubleshoot and identify the problems with low signal strength or noise. Without one, it's just a guessing game.

I've had one of these for years:
http://www.act-solutions.com/PCC/pdfs/PCCS.../at004_spec.pdf

I don't do much X10 any more, but when I do, this tester has been a big help...

Cheers,
Paul

 

[dth122]

Thanks for all the advice. I have one of Jeff's analyzers on its way to me now, so hopefully that will help solve or at least quantify the situation. If I determine that it's just noise or low signal level, I'll give one of his boosters a try. The difference in signal level is large and significant vs. the Leviton, so I could see that taking care of the problem immediately if my only real issue is marginal signal level.
- Dave