US240 switch meltdown

PaulD

Active Member
Had my first switch casuality in my new house. I have a number of US240 switches controlling wall outlets where I might put a lamp or other light load. Our housekeeper always turns on every light switch in a room when she is cleaning and then turns them out as she finishes a room. She is not fully familiar with the fact that the switches may only turn on the outlet in a dimmed mode. As a result, all the switch controlled outlets are hot but she may not realize that it may be in a dimmed condition.

Today, after she had turned on all the switches, she plugged a floor steamer into one of the controlled outlets and it fried the switch controlling the outlet. Switch was smoking and blackened the switchplate. Had to replace the switch as well as the rocker cover due to slight melting of the plastic rocker. In addition, there was another outlet controlled by the same switch which had a small lamp plugged in and the lamp remained on with no control from the switch. As a result, the switch failure mode allowed power to continue to flow to the outlets (not good). This compounded the problem because the floor steamer was still plugged in and trying to draw current which meant the switch was still trying to feed power to the outlet and getting hotter by the second. Fortunately, I was nearby and the housekeeper called me in to see the smoke coming from the switch. When I realized what was going on, I unplugged the steamer and the smoking stopped but the room now smelled like burning rubber. Obviously not good and this is a scenerio that my wife or guest could have created as well with bad results if they did not unplug the device creating the high load. I would have expected that the US240 would fail in an "open" condition for the power flow to prevent continued heating of the switch which might start a fire however, that is not what happened.

My lesson learned is to minimize the opportunity for someone to plug in a high current device into a outlet which may not be suitable for that type of device. My fix is to put a child proof insert into every switch controlled outlet which is only to be removed to plug in a dimmable device such as a light. I intend to put a label on each plug with something like "Lamp Only". Not a perfect solution but it is one I think will work in my situation.
 
wow, I am glad to hear no one got hurt, but I would get rid of the dimmer option all together, and just make it an on/off switch. This is way too dangerous, always assume the worst can (and will) happen.
 
wow, I am glad to hear no one got hurt, but I would get rid of the dimmer option all together, and just make it an on/off switch. This is way too dangerous, always assume the worst can (and will) happen.

I think it is against NEC to put a dimmer switch on a switched outlet for this very reason. Your safest bet might be to put in a UPB outlet and wire the US240 with no load and then link them. I believe the outlets are rated for a higher wattage.
 
wow, I am glad to hear no one got hurt, but I would get rid of the dimmer option all together, and just make it an on/off switch. This is way too dangerous, always assume the worst can (and will) happen.

After thinking about it more, I think that eliminating the dimmer option is the best option. Most of our lamps are three way switched anyway so we can still get a low light if we need one.
 
There is one room in my house that I wired this way and intend to keep it; however, it is the Master Bedroom and it is because we have no light fixtures otherwise. I figure I'd eliminate the switching outlet everywhere I don't have something plugged in and call it good. You make me feel like changing the plug to a non-standard plug so that only a lamp will fit. Perhaps to a Euro 220v. It would give me an excuse to shorten/hide the lamp wires as well.
 
I use Insteon in my home, but the idea is the same.

In my bedrooms where the house was originally wired with a switched outlet, I wired the switch to be a dummy and changed the outlet to be always on. I then installed an Insteon switch in the wall, and use a LampLinc module to control the lamp.

Cost might be higher, but now I have the ability to move the lamp around the room if we decide to rearrange - it's no longer tied to a particular ouetlet.

Controlling an outlet with a dimmer switch is definitely (as evidenced here) not a good idea...
 
I had a similar situation with a 240 and a Ceiling fan light. I had just installed the fan, and could not tell if the light was on or off from the pull switch. When I tugged on the pull switch, the lights came on and flickered. At that moment my wife walked in and told me that the box was glowing. Best I can tell, the cheap pull switch caused a situation the dimmer did not like.
 
Controlling ceiling fan lights shouldn't be an issue (I do this myself), unless you have special bulbs in there.
 
Controlling ceiling fan lights shouldn't be an issue (I do this myself), unless you have special bulbs in there.

Yeah, I've done dimmers on ceiling fans too. There was a hum at low speeds, but my understanding is the only risk is to the fan motor, not a risk of blowing up a switch or fire.
 
I was looking into building some of these, so I could control my fans in my house.

Just takes a "dim" in, and produces a proper "motor" signal. There was a few guys interested over on the HS forum. Didn't get enough interest to build a set.

No-Hum Fan Controller
 
I was looking into building some of these, so I could control my fans in my house.

Just takes a "dim" in, and produces a proper "motor" signal. There was a few guys interested over on the HS forum. Didn't get enough interest to build a set.

No-Hum Fan Controller

If you don't want to mess with a home grown solution that requires a two gang space, the Lightolier Compose Fan Controller is a true no hum three speed controller. It's still X10 unfortunately, but even without their firewall installed it works pretty reliably just in X10 compatibility mode.
 
Another option might be to "embed" an inline dimmer into the base of the lamp if there is room. I've thought about doing this with a couple of the Wife's lamps where the outlet is out in the open so the plug-in dimmer isn't visible to the guests/kids/wife.

Terry
 
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