Maestro Dimmer Giving Me Fits!

Dennis Alwon

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Chapel Hill, NC
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Electrical Contractor
I guess I'm confused. I thought he meant that if he hooks up a 100W bulb at the switch as an additional load, either to the line or load side terminal, the dimmer works correctly and that putting the same light bulb on the load side of the fan control module doesn't fix anything. If that were the case, I'd suspect that some interference is messing with the signal between the controller and module in the fan that a light bulb is smoothing out. It would still be possible that something in the fan is the source of that interference - possibly some PCB for load control or fan control.

That is correct-- he says a load on the other switches in the box that have nothing to do with the fan , would allow the system to work when a load was on it. Sounds like the switch leg goes thru the maestro but he says no.

The 100 watt bulb at the fan location with the light to the fan disconnected will not work properly unless those other switches have a load. It is very strange- he says the bulb is 40 watt but did not check however with the fan light disconnected it would not matter as the pigtail had 100 watts.

This is why I said run a new temp circuit all the way and see what happens.
 

gar

Senior Member
140427-1334 EDT

The important point of the original post is:
The problem is the dimmer stopped working. If you hit the button to dim/raise the light, the LEDs would just scroll up & down but no dimming took place. Now the crazy part I mentioned. He said he discovered that if he turned on another switch in the box the dimmer would work.:? I checked it and sure enough that was the case.
That is a lower impedance shunt at the input to the Wall Control makes the system work correctly. That lower impedance is the can lights when turned on. Thus, some low impedance shunt at some higher than line frequency is needed at the input to the Wall Control.

.
 

Dennis Alwon

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Chapel Hill, NC
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Electrical Contractor
140427-1334 EDT

The important point of the original post is:


That is a lower impedance shunt at the input to the Wall Control makes the system work correctly. That lower impedance is the can lights when turned on. Thus, some low impedance shunt at some higher than line frequency is needed at the input to the Wall Control.

.

Surely that can't be the issue as this worked for 6 months and I find it hard to believe that the line side of the switch would need that. If that is the case there would be issues like this all over
 

Little Bill

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Location
Tennessee NEC:2017
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Electrician
The customer is fine with me finding independent fan and light controls. He would like something that looks similar however, such as LED indicators. That is for the fan control. He just wants a dimmer that would look good beside the fan control. He doesn't even care if it dims or not as he said he hardly ever turns on the lights at the fan anyway.

But for my own peace of mind I'm going to ask him if I can do as Dennis suggested and run a different piece of NM from the wall control to the fan/light. Also to take an extension cord, plug it into a different circuit with the female end cut off and tie it to the new piece of NM. This all on my dime of course just to help me understand what might be happening. Also so I will know if I run into this again.

I have another unit just like this in the customer's bedroom that works fine. I also have 2 of these in my own house and no problems there either.
 

GoldDigger

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Staff member
Taking a purely logical approach to this issue, I come up with the following:
1. Since the indicator lights on the control change but the remote does not respond, the problem is in the communication between control and remote.
2. The two possible types of communication problem here are open circuit and interference.
Open circuit is not in play here since the lights come on but do not dim.
3. That leaves interference.
SWAG: Something in the house, on wiring near the problem area, is generating RF noise. It was not there or not arcing when the control was first installed. It results in high RF noise on the hot lead in the box, but when any local load is connected to that hot the voltage divider effect of that load and the inductance of the incoming hot wire reduces the RF level to a point where the control can work.
4. Hypothesis: Adding a small ceramic capacitor from hot to neutral at the input of the control will cure the problem.
5. Finding the new interference producing equipment (maybe with a portable radio?) is the long term solution.

Tapatalk!
 
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Little Bill

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Tennessee NEC:2017
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Electrician
Taking a purely logical approach to this issue, I come up with the following:
1. Since the indicator lights on the control change but the remote does not respond, the problem is in the communication between control and remote.
2. The two possible types of communication problem here are open circuit and interference.
Open circuit is not in play here since the lights come on but do not dim.
3. That leaves interference.
SWAG: Something in the house, on wiring near the problem area, is generating RF noise. It was not there or not arcing when the control was first installed. It results in high RF noise on the hot lead in the box, but when any local load is connected to that hot the voltage divider effect of that load and the inductance of the incoming hot wire reduces the RF level to a point where the control can work.
4. Hypothesis: Adding a small ceramic capacitor from hot to neutral at the input of the control will cure the problem.
5. Finding the new interference producing equipment (maybe with a portable radio?) is the long term solution.

Tapatalk!

That makes sense, and is a lot better answer than I got from Lutron.
The last thing they told me before ending the call was that I needed to find the open neutral!:happyno:

Edit: I just noticed you said the LEDs change. I did say that sort of. What I said was they "scroll" meaning they light up top to bottom continuously, which is an error code. The code says the unit needs resetting or wiring error. I both reset it (to no avail) and checked the wiring. Only thing I didn't do is change the wire, which I don't really think is the problem since my test light worked and 120V was present.

Only thing that would stop the scrolling was to pull out the service switch (kills power to the canopy module), turn on another load, then the control would work correctly. Meaning the LEDs would change according to the level you set it, but not scroll.
 
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Little Bill

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Location
Tennessee NEC:2017
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Electrician
In that case the interference may be so high level that the control cannot reset properly or it thinks that it is getting an error message from the remote.

Tapatalk!
It should either confirm or rule out interference if I powered the unit from another circuit, yes? Or would the interference be RF and would interfere regardless of power source?

If the latter, it's not bothering the other unit in a bedroom next to this room.
 

gar

Senior Member
140427-2341 EDT

Dennis:

In post #9 I suggested trying a shunt 0.1 to 1.0 mfd capacitor at the input to the Wall Control because when a shunt resistance, can lights, were turned on the problem was eliminated. At 60 Hz 0.1 mfd is about 26,000 ohms, and 1.0 is 1/10 that. At 100 kHz the capacitor impedances are 15 and 1.5 ohms. We can guess that the communication signal is of a much higher frequency than 60 Hz.

We have no details on the circuit other than the Wall Control appears to be a series element with the entire fan light and fan load. Whether the ground terminal is a means of getting energy to the electronics in the Wall Control is unknown. It also could be an RF path for the high frequency control signal, but unlikely based on the observation that low impedance at the input eliminates the problem.

Why the system originally worked and does not now is up for speculation. Most likely something in the home changed that has not been discussed. Like a TED energy monitor was added. But I don't think a TED system is the problem source.

One really needs to know much more about the Lutron system to try to deduce a cause.

.
 

BMacky

Senior Member
Location
Foster City, CA
Lutron has 24/7 tech support. I'd call them. Also, I had a Maestro that was affected by the noise an exhaust fan was kicking back downline to the dimmer through a shared power source in a multi-gang box. Customers complaint was lights stopped working but if you turned on the fan they would go through the fade cycle and come back up to the pre-set. I would suspect some interference there. Call Lutron.
 

Dennis Alwon

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Location
Chapel Hill, NC
Occupation
Electrical Contractor
Lutron has 24/7 tech support. I'd call them. Also, I had a Maestro that was affected by the noise an exhaust fan was kicking back downline to the dimmer through a shared power source in a multi-gang box. Customers complaint was lights stopped working but if you turned on the fan they would go through the fade cycle and come back up to the pre-set. I would suspect some interference there. Call Lutron.
He did call Lutron and had no luck--- they said it was a bad neutral but were perplexed by the problem.
 

Little Bill

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Location
Tennessee NEC:2017
Occupation
Electrician
UPDATE

UPDATE

I had to go back to the customer's house for other work. He had asked me to order a separate fan control and dimmer (meaning individual units). So I just planned on doing all the work in one trip. With the other work to be done, I only had a short time for further testing of the existing combo unit.

I didn't get to do all the things I wanted so I just did a couple of things to see if they would help.
First thing I did was to make sure the unit was still not functioning correctly. It was not.

Then I went to the panel to separate the kitchen circuit from the one the unit is in. These are in a generator back up panel and just pigtailed to the breaker. I just connected only the affected circuit to the breaker.
That did not change things at all. So that assured me it wasn't something on the kitchen circuit that was causing a problem.

Only other thing I did was to do a "factory reset" on the unit. It didn't help either, and I had done that before.

So I installed the replacement fan control and dimmer. These were Leviton, separate fan control and dimmer. These units don't have a canopy module, just the wall units with no RF circuitry.
Both units worked perfectly. So I know wiring is/was correct and that was not the problem.

Since I have the same Lutron unit at my house, I decided to try the customer's unit at my house.

I didn't change the canopy module at my house since I really didn't feel like taking my fan down tonight, so I just put in the wall control.

After I installed the wall unit it first acted the same as it did at the customer's house. So I did the "factory reset" and it then worked as it should. So I now know for sure the wall control is ok. Also, I used the same terminals here as I did at the customer's. Meaning there is two terminals for the load wires, depending on if you need it for 3-way or SP.

I may change the canopy unit later just to confirm it but since Lutron told me all the canopy modules were exactly the same, I really don't think there is anything wrong with it. I believe the module just passes through whatever the wall control tells it to.

So only thing I can imagine the problem is would be some kind of interference. I really don't know what it is and it's odd that he has the same unit in his bedroom and it is working as it should.

I suppose I could try the unit from the bedroom to see how it does in the living room.
I would just call it done, but the guy doesn't like the looks of the Leviton devices.:rant:
To me, they look very similar, as the Levitons have the "decora" look and even LED indicator lights, but....:roll:
So I'm going to have to do something anyway.
 
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gar

Senior Member
140509-0956 EDT

Little Bill:

I suggest that Lutron has a design and/or hardware problem.

The troublesome control failed at your home when you first tried it, but worked correctly after being reset. This means the internal microprocessor can be put into a state that causes the problem, and it retains that state. Probably means one or more changeable parameters within the processor gets modified, and is corrected when the reset is performed.

Some external noise or transient is capable of causing this parameter change. That cause is present in your customer's home, but not in yours. Further, it is likely in the circuit leading to or from the controller in the customer's home, and not in circuits associated with the other control in the customer's other room.

.
 

ELA

Senior Member
LittleBill,

The troubleshooting section talks about scrolling LEDs on the unit as an error code, as you mentioned.
But it also is specific about either the bottom or second from the bottom as being on to further define what the error is.
Did you note that somewhere and I missed it?

I work with Home Automation a lot and often encounter issues with units that communicate via the power line. In some cases a capacitive filter will help and in others it may make things worse. Units that operate without a neutral often have even more issues.
It is also common on devices like these to have one work fine in one area of a home and another in an adjacent room have issues.

If you are very interested in determining what is happening it may require getting serious with an oscilloscope and looking at the signals on the line and how they vary from one location to another.
When communications are marginal in one area it does not take a lot to change from operating properly to to a failed state.

As already mentioned earlier by Gar you could experiment with a filter to see the effects.
 

Little Bill

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Location
Tennessee NEC:2017
Occupation
Electrician
LittleBill,

The troubleshooting section talks about scrolling LEDs on the unit as an error code, as you mentioned.
But it also is specific about either the bottom or second from the bottom as being on to further define what the error is.
Did you note that somewhere and I missed it?

I believe the bottom LED was on with the top section scrolling. The spec sheet lists that as: ."unit is not activated" or "wiring error"
I only got that error code once. The rest of the time the unit just would not function.


I work with Home Automation a lot and often encounter issues with units that communicate via the power line. In some cases a capacitive filter will help and in others it may make things worse. Units that operate without a neutral often have even more issues.
It is also common on devices like these to have one work fine in one area of a home and another in an adjacent room have issues.

If you are very interested in determining what is happening it may require getting serious with an oscilloscope and looking at the signals on the line and how they vary from one location to another.
When communications are marginal in one area it does not take a lot to change from operating properly to to a failed state.

As already mentioned earlier by Gar you could experiment with a filter to see the effects.
What is the filter called?
Where would I get one?
Exactly where would I install the filter, between the incoming power and the wall control or between the wall control and ceiling module?

BTW, thanks Gar for your reply!
 

ELA

Senior Member
Little Bill,

I did a quick look to see if Lutron explained anything about the communications method being used or anything about how the transmitter derives its power ( minimum wattage requirement) . That is also something Gar had questioned earlier. Without more detail on the system parameters, and without using an oscilloscope, it is a bit of a shot in the dark.

Since the bottom LED was on that did not indicate a communications problem. As was stated the unit was in a corrupted state and required a factory reset to recover. That would seem to indicate an possible interference source that could possibly be filtered by a simple capacitor filter.

The Lutron device does not require a neutral, but is there a neutral available in the box where it is located? If so then you could try a 0.01uf capacitor ( rated for across the line usage) from the hot to the neutral in the box. If there is no neutral you could try from hot to ground, but strictly as a test since this is leaking 60hz current to ground.
As mentioned this may help but then again it could also make things worse as such a filter may also shunt an intended higher frequency communications signal.

A more appropriate filter would be one that is specifically designed to be compatible with the communications frequency being utilized by Lutron. Such filters can be designed to shunt unwanted interference while still isolating the intended communications frequency from the shunt.
Too bad Lutron could not be more helpful in that regard.

Sorry this is not all that helpful but more information is required about the system to better understand what a fix might consist of.

While you have it on a test bench it might be interesting to measure what level of currents flow through the transmitter into the receiver when neither the light or fan are on.
I am not clear on whether or not this might be valid but I wonder if a small resistive load in parallel with the input to the receiver would be helpful ( or a bad idea)?
Providing a lower impedance without having to have an adjacent switch on as you noted helped.
 

Little Bill

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Location
Tennessee NEC:2017
Occupation
Electrician
Little Bill,

I did a quick look to see if Lutron explained anything about the communications method being used or anything about how the transmitter derives its power ( minimum wattage requirement) . That is also something Gar had questioned earlier. Without more detail on the system parameters, and without using an oscilloscope, it is a bit of a shot in the dark.

Since the bottom LED was on that did not indicate a communications problem. As was stated the unit was in a corrupted state and required a factory reset to recover. That would seem to indicate an possible interference source that could possibly be filtered by a simple capacitor filter.

The Lutron device does not require a neutral, but is there a neutral available in the box where it is located? If so then you could try a 0.01uf capacitor ( rated for across the line usage) from the hot to the neutral in the box. If there is no neutral you could try from hot to ground, but strictly as a test since this is leaking 60hz current to ground.
As mentioned this may help but then again it could also make things worse as such a filter may also shunt an intended higher frequency communications signal.

A more appropriate filter would be one that is specifically designed to be compatible with the communications frequency being utilized by Lutron. Such filters can be designed to shunt unwanted interference while still isolating the intended communications frequency from the shunt.
Too bad Lutron could not be more helpful in that regard.

Sorry this is not all that helpful but more information is required about the system to better understand what a fix might consist of.

While you have it on a test bench it might be interesting to measure what level of currents flow through the transmitter into the receiver when neither the light or fan are on.
I am not clear on whether or not this might be valid but I wonder if a small resistive load in parallel with the input to the receiver would be helpful ( or a bad idea)?
Providing a lower impedance without having to have an adjacent switch on as you noted helped.
I was thinking about calling Lutron again and asking to speak with someone who could explain exactly how the wall control communicates with the canopy module. Maybe that would help me, or confuse me!:D

What would/could I use for a small resistive load? It would have to be in the 3-gang wall box as the ceiling box is just a "saddle" box that mounts to the underside of the ceiling joist. It is a fan rated box though.

I think it would work because when I connected my test light (light socket with pigtail leads) to the wall control it allowed the unit to function correctly.
 

Little Bill

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Location
Tennessee NEC:2017
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Electrician
While you have it on a test bench it might be interesting to measure what level of currents flow through the transmitter into the receiver when neither the light or fan are on.
ELA,

I decided to do a bench test while I have the customer's unit here at home. I didn't have any kind of motor to mimic the fan motor so I just used a 100W light bulb. I also used a 60W light bulb for the light portion.

Here is what I did and the readings I got.

power on to the wall control (transmitter) which passes through to the canopy module (receiver) with neither the light or fan on = 124.5V-.08A

just the light (60W) = 122.1V - 0.45A

just the fan (100W bulb representing the fan) = 122.2V - 0.69A

both the light and fan on = 121.9V - 1.13A

I don't know if this helps you or anyone else here but I was curious myself.
Mainly, I didn't want to take my fan down to check his canopy module :happyno: but I did want to make sure it was working and communicating with the wall control.
 

gar

Senior Member
140510-1558 EDT

Little Bill:

I have found incandescent bulbs to be fairly close to rated wattage at rate voltage.

A 100 W reads 122.4 V 0.83 A 101 W calculated power 101.6 W.
A 060 W reads 122.7 V 0.49 A 061 W calculated power 060.1 W.

With a Lutron three wire dimmer I read 58 W on the 60 W bulb.

Your calculated power values are low. This implies the dimmer function is not turning on at 0 deg, but some phase shift later at maximum on, and I would expect that.

Back in one of the earlier posts I suggested putting a 0.1 to 1.0 ufd ceramic capacitor in parallel with the input side of the Lutron control. At 60 Hz this is about 26,000 ohms, and lower as frequency increases. Use a 1000 V rating. The capacitor will dissipate very little power. A 1 ufd will have 1/10 the impedance of the 0.1 at any specific frequency that is moderately below self resonance of the capacitor. 1 ufd gets bigger and more expensive.

If a low source impedance is needed at higher frequencies, then a simple capacitor may solve the problem.

Are you able to get the control back into its malfunction state at your home?

If possible it is important to try to find the source that causes the malfunction. Since it remained in the bad state while you transported the control from one place to another it implies corruption of some memory location for some parameter in the control.

.
 
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