New Illuminated Handrail Build - LED Strip on dimmer very slow to turn on

I just finished a new handrail build with a recessed aluminum channel and LED strip. I’m very happy with the way it turned out other than if being crazy bright at anything greater the 5% brightness. I’m using a couple of Iris 2nd gen motion sensors. The one on the 1st floor is mounted to the first step riser and triggers reliably when I walk into the landing area. The motion sensor on the 2nd floor has the PIR sensor mask on each side to act as a curtain sensor and likewise triggers reliably. I’m not crazy about the looks or placement of 2nd floor motion sensor so I’ll likely replace it with a Hue motion sensor and 3D print a mount that I can recess in the sheetrock. Assuming I can resolve the following issue:

I’m seeing a delay of what seems like 2+ seconds (using the science based “one Mississippi, two Mississippi” method) from the time the motion sensor is triggered until I see the LED strip turn on. By that time I’m already on the second step (assuming I haven’t already fallen down the stairs) so the delay is a bit of a problem. The issue only seems to happen at low dim levels which has me thinking that it’s related dim ramp up time. The same occurs if I try to set the level to 5% from the Hubitat device page UI. The problem persists until approx. a 20% brightness setting. If I set the brightness to 20%, the strip seems to turn on in less than one second. Unfortunately, 20% is much too bright in the middle of the night so that’s not workable.

I’m using a UltraPro Z-Wave dimmer which I believe is the same as the GE Enbrighten series dimmer. I’ve tried the Generic Z-Wave Dimmer and GE Enbrighten Dimmer drivers both behaved the same way. I’ve also tried using the Basic Z-Wave Tool driver to set Z-Wave parameter 8 (dim rate step timing) to a value of 1 (default is 3) using the info found here: Advanced Configuration but it made no noticeable difference. I suspect the LED driver and LED strip don’t like the dim level ramp up at low brightness value. Does anyone know if it’s possible to completely eliminate the ramp rate so the dimmer goes to a set brightness instantly without ramping?

[EDITS] Change title for clarification. Remove extra images

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Do your sensors support association? If so that might decrease the response time as it needn't go through the Hub.

This doesn't appear to be a motion sensor response time issue as the problem also occurs when I control the dimmer from the Hubitat device page. But as I mentioned, it only occurs when the dim level is set to 20% or less--the lower the dim level, the slower the turn on time seems to be.

To summarize:--From the device page:

Set dim level to 20% and click "Set Level" button and LED strip turns on in under 1 second.
Set dim level to 5% and click "Set Level" button and LED strip turns on in 2+ seconds.

In either case turning the dimmer off is nearly instantaneous so this doesn't appear to be a zwave mesh issue.

Behavior with motion sensors and RM rule is identical.

You didn't mention the dimmer. Many dimmers have programmable ramp up and ramp down times. I realize it shouldn't normally be effected by level but worth a look.
You will have to look for advanced settings in your dimmer manual, not the device driver.

Actually, I did. I even mentioned changing the ramp timing parameter :grin: Unfortunately, that seems to have had no effect on the problem.

How are these LED powered? I see you are using the Ultrapro switch, but there must be some LED driver?

I know on some of my LED recessed lights, they will light up correctly at say 50%, and you can dim them to 10%, but if you try to go from 0% up to 10% they won't light.

The LED just don't have enough voltage to conduct I suppose, but once conducting they will continue to do so. Or maybe it is a limitation of the LED voltage regulation or AC to DC converter circuit?

Either way, I think it is a limitation of the technology with LED compared to incandescent bulbs.

Yes, I'm using this 60W dimmable LED Driver. This driver actually illuminates the LEDs at 1% dim level. But I think the issue I'm seeing is that the dimmer is still ramping despite my having changed the dim step parameter to its smallest value of "1" which equates to a step every 10ms . So for a good portion of the ramp up, the signal being fed to the LED strip is insufficient to drive the LEDs.

The question is; is it possible to completely eliminate the dimmer's ramp rate?

EDIT: in the interest of thoroughness, I'm using this LED strip

I haven't used the newer Jasco stuff, but for everything I have seen made by them there isn't a parameter to set this.

Zooz dimmers on the other hand, do have both minimum level and ramp rate including instant ramping. ZEN77 S2 Dimmer 700 Advanced Settings - Zooz Support Center Maybe try one of those and see if it is better for your use-case? Zooz aren't that expensive, and you probably could use the Ultrapro switch elsewhere.

I think you would want the Zen77 based upon this chart, no minimum load requirement.

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Sorry I scanned for a part number and missed the detail.

How are the LED powered. (same question as neonturbo).

Is the lag still present when you use the machinal button on the dimmer?

My LED's are powered from a powersupply that can be controlled by a 0 to 10V signal. It lags when I use a wall dimmer but is quick to light up when using the 0 to 10V signal.

Another thought. Having no carpet I was able to put LEDs under the front lip of the stairs. They are very dim (by design). They only take about 0.5 watts so I leave them on all the time. May not work for you.

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Yeah, ZEN77 looks like it should work--good call:

Parameter 28: Adjust the ramp rate ON for your dimmer when a Z-Wave command is sent to turn the dimmer on (Z-Wave ramp rate on). Values correspond to the number of seconds it take for the dimmer to reach full brightness when operated via Z-Wave.

Values: 1 – 99 (seconds). 0 – instant on. 255 – match physical. Default: 255.

Size: 1 byte dec

No worries. The dimmer is connected to a 60W dimmable LED driver (link included a couple of posts up). The issue isn't apparent when physically using the dimmer which has me wondering if the ramp rate parameters only affect physical dimmer actions and not z-wave commands.

Regarding LEDs under the lip on the stair tread; It's good option but I don't have access to the underside of the stairs so this would be pretty difficult without busting through the sidewall and ceiling of the closet below the stairs. That and I've already invested a lot time on the handrail and like the way it looks.

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Little bit off topic, but I like the look of that handrail and the lighting. Did you use a prefab rail, and route out a groove for the LED channel? Or did you build the whole rail from scratch?

It's a 16' prefab from Lowes. Getting it home in on my RAV4 was an interesting engineering project by itself.

To route the dados in the handrail, I build a sled with guides that ride on the sides of the handrail for my trim router and routed a 3/4" wide X 5/16" deep dado for the LED channel. I made some small blocks that are 3/4" wide X 5/16" high and the same length as the hand rail bracket where it attaches to the handrail. The blocks fit inside the dado and have 1/8" rabbets on their inside long edge to allow routing the wires that connect to the individual sections of LED strips. Power to the handrail comes in at the 90 degree handrail return on the second floor. It's a pretty clean setup with no visible wiring anywhere even when you look at the bottom of the handrail or at the 90 degree return.


I think your handrail looks great. I was only describing my setup as it takes so little energy I don't worry about turning it off.

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That looks great :+1:

They have been running constantly since 2015. I'm starting to see a small amount of color shift in some but for the most part they're holding up pretty good. They are so dim that during the day you can barely see them, but a night they are perfect.

Its been a while but I believe they are running at about 1% duty cycle.

Best of all, they have a very high WAF.

You probably already have this worked out, but...

One trick for this is instead of doing an ON, do a Set Level to the desired % with a specified duration of 0 - at least on drivers that will turn ON based on level changes (which are most, but not all, of them).

Per the zwave spec specifying duration of 0 is supposed to bypass any ramping rates. And in my experience it does on all switches I have done it on.

If it is still slow to turn on/get to brightness then, well it has to be the LEDs themselves.

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Yup, it's one of the things I tried. Unfortunately, the behavior was identical to using an on command after having set the dim level. I even tried turning it off be setting the level to 0 hoping that might result in a quicker "on" time but no luck there either.

At this point I'm convinced that the Jasco dimmers have some built in ramp duration that can't be overridden regardless of what parameters 7 and 8 are set to. The ZOOZ ZEN77 suggested by @neonturbo sound like it'll do the trick. Unfortunately, I'll be away for several weeks before I can give it a try.

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Have you considered the delay may be in the driver? When power is off the driver circuitry is not powered. Now when you apply a low %on time perhaps the driver electronics takes some time to get enough power to provide an output.

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While that's certainly possible and very likely there is some amount of LED driver delay, I would expect that the delay from an "on" command until the LEDs illuminate to be constant regardless of dim level.

So, let's say there was a 1 second power up delay (which strikes me as VERY long) in the LED driver itself, the amount of time it takes for the LEDs start to illuminate at 5% brightness should be the same as for 20%. But that's not what I'm seeing--at 20%, the LEDs illuminate in approx one second. At 5%, it's well over two seconds.