Problem With Lutron RF Switch

[Little Bill]

I put in a Lutron wireless RF switch for a customer a couple of days ago. I will put a link to the switch below. I put it in a 2-gang box that contained another switch which was just a regular switch (might have been a 3-way, as I didn't notice). That left me with needing a 2-gang plate with Decora on one side and toggle on the other. I didn't have a plate with me and the customer said he would pick one up and put it on.

Now a few days later, he calls and said when he went to put the plate on the wireless switch was so hot he couldn't touch it. He took it loose and asked me to come back and check it. Since he's quite a distance away I want to only make one trip so I need to know if something is wrong in the wiring or in the switch itself. If the latter, I need to order a replacement. Anyway I just want to know what to look for when I get there.

Let me add that this switch doesn't require a neutral. I don't know if it uses the EGC or not. However, the house was wired before switches required an EGC. So there was no EGC in the box so the EGC from the switch isn't connected to anything.

So what could be making the switch get so hot?
ETA: The switch works about (4) 4' fluorescent lights

Here's a link to the switch. You can scroll down the page and find the PDF files for install and specs. If you're not familiar with the switch these files will explain. This switch is exactly the same as the Caseta.

https://www.1000bulbs.com/product/117305/LUT-PD5SDVWH.html

 

[MNSparky]

I put in a Lutron wireless RF switch for a customer a couple of days ago. I will put a link to the switch below. I put it in a 2-gang box that contained another switch which was just a regular switch (might have been a 3-way, as I didn't notice). That left me with needing a 2-gang plate with Decora on one side and toggle on the other. I didn't have a plate with me and the customer said he would pick one up and put it on.

Now a few days later, he calls and said when he went to put the plate on the wireless switch was so hot he couldn't touch it. He took it loose and asked me to come back and check it. Since he's quite a distance away I want to only make one trip so I need to know if something is wrong in the wiring or in the switch itself. If the latter, I need to order a replacement. Anyway I just want to know what to look for when I get there.

Let me add that this switch doesn't require a neutral. I don't know if it uses the EGC or not. However, the house was wired before switches required an EGC. So there was no EGC in the box so the EGC from the switch isn't connected to anything.

So what could be making the switch get so hot?
ETA: The switch works about (4) 4' fluorescent lights

Here's a link to the switch. You can scroll down the page and find the PDF files for install and specs. If you're not familiar with the switch these files will explain. This switch is exactly the same as the Caseta.

https://www.1000bulbs.com/product/117305/LUT-PD5SDVWH.html

The specs say it's rated for max 4 amps fluorescent when installed at the end of a gang. With it controlling four 4' fixtures, I'd say you are around 2.5-3 amps if each fixture has two 32w lamps. Is that accurate?

the closer you get to that max, the hotter it will get. I see this a lot with 600w dimmers that are around the max.

 

[Little Bill]

The specs say it's rated for max 4 amps fluorescent when installed at the end of a gang. With it controlling four 4' fixtures, I'd say you are around 2.5-3 amps if each fixture has two 32w lamps. Is that accurate?

the closer you get to that max, the hotter it will get. I see this a lot with 600w dimmers that are around the max.

To be honest, I didn't really look at the lights to see of they were 2 or 4 lamp. This is only a switch and not a dimmer if that matters.

Also, I don't know if a regular switch counts against the rating since it is not a dimmer or other electronic device.

 

[MNSparky]

If it's the switch in the specs you included, the 4 amp max would apply. It has internal electronics that allows it to be the master for remote switching. It's not going to be as robust as a normal single pole switch. The max amp rating also gets reduced if any of the removeable heat sink tabs on the sides have been removed.

My guess is you are somewhere close to, at or over the max amps. A call to the homeowner to ask how many lamps are being controlled would confirm this. That would cause the switch to be warm or hot. I would look for a higher rated switch to bring with you when you go.

 

[Little Bill]

If it's the switch in the specs you included, the 4 amp max would apply. It has internal electronics that allows it to be the master for remote switching. It's not going to be as robust as a normal single pole switch. The max amp rating also gets reduced if any of the removeable heat sink tabs on the sides have been removed.

My guess is you are somewhere close to, at or over the max amps. A call to the homeowner to ask how many lamps are being controlled would confirm this. That would cause the switch to be warm or hot. I would look for a higher rated switch to bring with you when you go.

Not that it makes much difference but what I'm saying is, I know what the switch amp rating is and know that it gets derated when other "like" switches or dimmers are in the box. What I'm saying is there is no other "like" device in the box, it's just a normal mechanical switch in with the RF switch.

I do agree I may be close or at the max, I'm just pointing out that I don't think the derating is involved since the regular switch does not have electronics or put off heat.
None of the tabs were broken off the switch.

 

[MNSparky]

Not that it makes much difference but what I'm saying is, I know what the switch amp rating is and know that it gets derated when other "like" switches or dimmers are in the box. What I'm saying is there is no other "like" device in the box, it's just a normal mechanical switch in with the RF switch.

I do agree I may be close or at the max, I'm just pointing out that I don't think the derating is involved since the regular switch does not have electronics or put off heat.
None of the tabs were broken off the switch.

Ok, sorry I read the original post wrong. Yes, you are correct, no derating needed if it's not ganged with another electronic switch. So I guess you'd be good for 5 amps then.

 

[JFletcher]

If it is that hot w/o the coverplate, it may have melted with it on. Is the box fill tight/overloaded? Those are only rated 3A in the middle of a box. I have to think a plastic or fiberglass box would hold heat more than a metal one too (no idea if that makes a difference). My money is on overload; 4 3 or 4 bulb fixtures would be pushing or exceeding 4A.

eta: I see the derating is with like devices. I'd measure the amperage it's operating at, but I still say overload; possibly something else on that circuit? Switched receptacle or a light elsewhere?

 

[Little Bill]

If it is that hot w/o the coverplate, it may have melted with it on. Is the box fill tight/overloaded? Those are only rated 3A in the middle of a box. I have to think a plastic or fiberglass box would hold heat more than a metal one too (no idea if that makes a difference). My money is on overload; 4 3 or 4 bulb fixtures would be pushing or exceeding 4A.

Box fill is fine, and it's just a 2-gang box.