Low Voltage Disposal Control

[clueless joe]

The switch for our Garbage Disposal is in an inconvenient spot. I was considering the following and want collective input about my idea:

I will buy a relay with contacts rated high enough to handle the disposal motor inrush. (calculating this is not something I know how to do) I would power the low voltage side with a leftover cell phone charger, through a doorbell switch which I would mount in a convenient and safe location. (safe means not where I could turn on the disposal by leaning on it accidentally) I would put the relay and charger cube under the sink, and be able to control the disposal with low voltage and low current. So what am I overlooking? Any input on specs for the relay?

Thanks Joe

P.S. I saw a TOH where they installed an Air Switch which inspired this idea. I would use that solution but I do not have a hole in my granite counter top to accommodate the air switch.

[JoeSpareBedroom]

Either way, you have to run a wire, right? Why not just do it right and run a little more AC wire, even if you need to use surface mount wire channel?

[John Gilmer]

Just run a 120 volt rated #12 cable from where the switch is now to where you want it.

It's not much more trouble to run #12 as to run low voltage wire. You are only going a few feet.

But if you insist upon a relay I believe there are special relays that effectively have the transformer built in. One design has a coil which is always energized but which has two potential flux paths. The higher "reluctance" path is via the armature when controls the load. The lower "reluctance" path has a few turns of wire which are connected to the low voltage switch. When you close the switch the low reluctance path has a "shorter turn" so the magnetic flux goes through the armature and turns on your motor.

But I still recommend you just put a 120 switch exactly where you want it.

[Joseph Meehan]

I don't like the idea.

1. you are now relying on a relay to break a circuit. If the relay fails, you have a problem. A switch is less likely to fail and if it does it almost always well fail open, not closed. I have had relays fail closed.
2. Why is it inconvenient. Will the new location meet the usual requirements for the switch. Frankly you want it to be inconvenient. You don't want to switch it accidentally or have a kid flip it. I really hated the way our builder put the switch next to the switch for the overhead light. Very bad idea. It has been flipped several times by accident, even after I painted it red.

I am considering putting in a more secure switch; some sort of momentary contact with a cover. Maybe I will add an additional standard switch that can act as a safety. Thinking about this there are some good ideas if I can find the right parts. One switch that would close the circuit for a limited amount of time like 60 seconds and a momentary switch to activate the disposal. ..

[Edwin Pawlowski]

A very complicated solution to a very simple problem. Buy a new disposal with the switch integrated in the stopper. Just a twist and it is on.

[Percival P. Cassidy]

We just got rid of one of those although it was working just fine. It was just so horribly INconvenient: there is no way to run the water and switch on the disposer, then gradually feed a large quantity of stuff through it. The only possible value I can see in such a thing is to prevent little children sticking their hands in a disposer while it's running.

Perce

[Percival P. Cassidy]

I have seen momentary-contact Decora-style switches that are specifically intended for garbage disposers.

Perce

[Edwin Pawlowski]

That is why they call it a batch feed. You put in a batch, let it go, then add more if needed. Frankly, I've never had more than what fits in a single batch at a time. They make different models for different people, but me, I'd only buy the batch feed type. If you have loads of stuff to get rid of, you should look into trash or a compost pile.

Also less chance of spoons ending up down in the disposal.

[Art Todesco]

[David Nebenzahl]

Art Todesco spake thus:

That sounds dangerous to me, not electrically, but mechanically. Maybe you don't have kids in the house.

All this talk makes me think how absurd it is that garbage disposals are installed as they usually are--that is, with a wall switch, often next to other switches that control lights, with absolutely no marking or difference of any kind to distinguish it from a light switch. (Like that TV commercial for Roto Rooter showing the guy fumbling for the disposal switch, with the sink all full of crap, but hitting a light switch instead.)

If I were writing The Code, I'd put something in there to make disposal switches clearly identifiable. They should probably be a whole 'nother type of switch, ideally some kind of momentary switch that can't be left on, and is far enough away from the sink to prevent any part of the body from contact with spinning blades.