Convert a Dimmer to a On/Off Switch

[breef]

I want to run CF lights with an Insteon dimmer (2477D). Is it possible to convert this to an on/off switch so it doesn't allow dimming?

[paulbates]

The switch will need to be replaced with an on/off switch. The manual documents that the dimmer's design doesn't support fluorescent lighting.

If its one or 2 bulbs per switch,  it might be cheaper to go LEDs than pay for new switches

[onetrack97]

Yes, you can do it.

If, the load isn't too high.  You need to:

- disable local programming

- 100% level or 0%, nothing in-between;

- Set ramp rate to 0.1s

That said, LED's are way better anyway and you get to dim them.

[Brian H]

If the CF is sold as Dimmable or marked as OK with a dimmer controls maybe. Some may and some may not play nice. Even at 100% on. Triac dimmers probably will not work reliably.  As they still modify slightly the AC wave at 100%. The switch, CF or both maybe damaged. Best and safest bet is go to a relay type that is On and Off only.

You can also have issues if you go to LED bulbs and they are not specified as dimmable.  As I have tried some not rated to be on a dimmer with a dimmer and bad results.

[onetrack97]

A Triac fully on should be a sine wave except for potentially some notches at the crossover points.  I know CF lights have their own internal ballast but it won’t make much difference if the input has a little distortion.

[lilyoyo1]

There are many articles online concerning the use of dimmers with non dimmable loads even at full on. Regardless of the chances of something going wrong, is it really worth 50 bucks and using the proper equipment

[Brian H]

Maybe in theory. A triac feeding an non restive load may not be close to a sine wave and dimmers also have a minimum load for stability. Heck we even see combinations of dimmable LEDs and switches acting strange. So picking a combination that works sometimes takes experimenting.

I have also seen many posts on trying to use a dimmer at 100% not working  correctly.

No one is stopping someone from trying it. Just remember you are the one that may damage the dimmer switch, damage the load or have a very unstable setup.

 

 

[onetrack97]

Yep, can be done, I’m doing it.  But, I also have experience in ballast design and fluorescent lamp usage.  There are lots of caveats.

Now that LED bulb prices are so low, I’d just switch to LED instead of changing the switch.

[paulbates]

Another factor is physically monitoring the switch itself. If it feels hot after 15-20 minutes, that's not good.

Also note you lose 200 watts of load capacity for each additional insteon switch you gang directly side by side.  If its a 600W dimmer, it becomes 400W when next to one insteon switch, and 200W if sandwiched between 2 insteon switches. Hot running switches is a symptom of this problem. While this has become less of a problem as CF and LED bulbs need less and less power, but needs to be considered in your installation if you're pushing the switches specs.

Paul

[lilyoyo1]

Just because a person can do something doesn't mean they should. Especially when there are other (low cost) options to do things correctly.