Fused dimmer module?

[Jonlarimore]

This is not a complaint, just a question:

Is it not possible to protect a solid-state power-controlling device from over-current destruction?

The reason I ask is that a family member just accidentally destroyed an Insteon plug-in dimmer module by plugging a vacuum cleaner into the dimmer’s extension cord to its Christmas lights. No biggie - I just bought a replacement and he learned a lesson.

Am I right in guessing that a twenty-cent thermal fuse would react too slowly to protect a triac and that’s why these dimmer modules are not fused? And that there’s no other practical fusible device which might protect them? Because … replacing a fuse might be considerably cheaper than buying a new dimmer … 😉

P.S. yes, I know I might have avoided the issue by plugging the dimmer into the extension cord rather than vice-versa, but for several reasons in this instance that just wasn’t doable. Also of course “If it hurts when you do that, don’t do that”. 🤣

[BLH]

The old 2456D LampLinc and 2856D Icon Lamp Module.
Did have a wired in 5S4A fuse from the line input pin to the board. In a shrink tubing insulator.
If the presently sold 2457D2 LampLinc modules. I have not seen it but it possibly could be surface mounted and I have missed it.

[INSTEON John]

If the presently sold 2457D2 LampLinc modules. I have not seen it but it possibly could be surface mounted and I have missed it.

BLH, you are corrent in that there is no fuse in the present Lamp Modules. To protect the electronics of the Lamp Module, there is an in-rush resistor that also operates as a fuse in case the electrincs of the module fail and there is an over curent condition.

The furse in the original LampLinc modules, rated at 4A also protected the load output. It was there but not necessary for the UL standard used at that time.

John

[Jonlarimore]

So apparently it is possible to use a replaceable fuse to protect Insteon dimmer module electronics. In that case I would suggest that any future updates to them include a user-replaceable (externally accessible) fuse.

[INSTEON John]

So apparently it is possible to use a replaceable fuse to protect Insteon dimmer module electronics. In that case I would suggest that any future updates to them include a user-replaceable (externally accessible) fuse.

Jonlarimore, the North American UL and CSA test for dimmers is very harsh on the units under test. Six testing samples must turn on and off the load rated at 150% of max for 100 cycles lasting between 6-10 cycles per minute (UL 1472-2006 section 5.3.1.4). Then those same samples have to survive 10,000 cycles at the full rated wattage (Test 5.4.1.1) All these tests are without failure. There is a test with 30Amps of power where the unit under test must not catch fire!

John

[Jonlarimore]

Thanks for that interesting info, John, but of course my initial suggestion still applies in that an externally replaceable fuse would be a highly desirable and inexpensive update to Insteon dimmer modules.

I’m.sure those modules have passed all the tests you mention, but accidentally plugging a vacuum cleaner into one will obviously still fry it (and has), and an 89-cent fuse is a lot cheaper than a $50 dimmer. 😉

[BLH]

It would be a race between the overload blowing a fuse and the triac controlling the loads current rating.
Too fast a opening would be premature blowing and too slow a triac shorting.
From what I saw in the old 2456D. Its timing curve would probably not protect from an inductive load like a vacuum motor.