US2-40 - Can it be used for 1000W?

mjpcomp

Member
I know that the specs and guides state that the Simply Automated US2-40 is rated for 900W, but is that just to ensure that if installed in a normal box, that the heat dissipation is adequate?

Has anyone here tried using the US2-40 switches to control a 1000W load (open/large box with cooling)?

I have seen that the HAI dimmers (which look about the same, save for the fins) have a 1000W rating, but in a NORMAL (average size) box, are instantly derated to 900W...

Any feedback is appreciated... I'd like to construct some dimmers for a few work lights, but don't want to have to go out and buy 1000W dimmers if I can use a few of my US2-40s to accomplish the same task.

If the reason that the US2-40s are rated for 900W is simple because of heat/cooling, then that can be taken care of, but if it's the actual electronics within that have a cap/fuse to shut off at 7.5A, then that could be an issue.

If you have tried it with 900+W, please let me know. THANKS!
 
I had a 3 gang box with 2 ea US240 plus a fan switch. One of the US240's controlled a wall outlet. Housekeeper had all switches turned on and plugged in a 800W floor steamer into the wall outlet which fried the US240 controlling the outlet. Smoke was coming out of the switch. Fortunately I was home and housekeeper called it to my attention. Smoke stopped when I unplugged the steamer. Interestingly, the switch failed in the ON position and continued to feed power to the outlet even as it was smoking. Never saw any flames but heat melted the cover. Do not know what would have happened if I had not been there take care of the situation.
 
Housekeeper had all switches turned on and plugged in a 800W floor steamer into the wall outlet which fried the US240 controlling the outlet.

Did you ever measure the draw of the steamer to see if it might have had a high startup draw (or might be above 800W on average)? I know that when you place multiple dimmers in the same box, you need to derate them (3-gang box w/2 load dimmers means 700W each, according to the derating guide in the US2-40 manual), so in your case, it seems like 700W was the max "safe" draw per dimmer.

For the bad dimmer, did you get it replaced, or tossed it? Would have been nice to know if it was a failure at a component, or if it had been heat (due to overrated draw).

(Just reviewed manual again): The US2-40s are supposed to have over-draw protection (thermal @ 120F)... You may have had a defective switch?

(Paul - thank you for your response, I appreciate it)
 
800W is what is on the lable. Do not know start up current draw. I never intended anything but lamps to be in that outlet. Did not think about househeeper or anyone else plugging in a high watt device. As a result, I went around the house and put a plug (baby safety plug) in each controlled outlet that did not have a lamp plugged in. Also told wife and housekeeper to not remove any plugs and plug in anything but a light. Lots of other plugs to use without using one of the controlled outlets. My fault it happened in the first place. I should have considered that possibility.
 
As a result, I went around the house and put a plug (baby safety plug) in each controlled outlet that did not have a lamp plugged in.

Hmm... I should get some of those myself - just in case...

What ever happened to the dimmer that failed?
 
An outlet on a dimmer is a bad, bad idea - baby plugs or no baby plugs. It might even be a code violation.

Just my 2 cents.
 
An outlet on a dimmer is a bad, bad idea - baby plugs or no baby plugs. It might even be a code violation.

Just my 2 cents.

It definitely is. So is having a switch controlling a potential load which can be much greater than the switch rating. If you have a 15A outlet, you have to assume that a 15A device could be plugged into it. Only a 15A relay switch would be appropriate here.
 
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