I am looking for a relay suitable for turning a 15A circuit on and off by using low voltage control wires, as follows:

- SPST would be find (i.e. something that just opens and closes continuity between line and load)

- the low voltage control can work either through shorting 2 contacts or providing a low voltage signal

- the whole assembly should fit in a standard single gang box that we can put a blank plate over

- the actual load is a towel warmer and will draw on a fraction of the 15A (I don't have the actual specs for that device, yet)

Would much appreciate any thoughts. Thanks.

Towel warmers usually indicate a better budget. On just about all towel warmers, we default to using ra2 with a simple power on/off. It will work with just about any control system. And you can automate it for them, ie monday-fri on at 7:30am - off at 9:30am.

Unsure of a low voltage controllable relay that fits single gang.

I have been using these relays for various types of power control projects over the years. They come in 12 or 24 vdc coils and will fit in a single gang box. You will want to protect the coil with a diode like a 1N4001 or equivalent.

[Link: mouser.com]

The relay from mouser should work just fine (and despite mouser's claim, it does not draw 30 amperes for the coil!), but I don't think you can do this legally in one gang.

High voltage and low voltage are to be in separate gangs, so you'll need a two-gang box with a divider. That's the way it's supposed to be, but that's actually silly because there's no way for the relay to control the high voltage without the high voltage wires connecting to the relay, that is, without high voltage and low voltage being in the same box. If you do this in one gang, any inspector or insurance inspector (after the fire) would have a valid argument that it was done incorrectly.

Sounds like control using relay power packs. Leviton is pretty easy to find most anywhere but other brands are available. Meant for line voltage in a box via a knockout and low voltage connected outside the box but plenty of options depending on what you need.

Specs are listed by model
[Link: leviton.com]

That takes care of the problem, but does the OP have to put this into an existing box? Can he even get to the outside of the box? That goes in the "complete description of the problem" category.

 As IRK suggested above; in situations like this, if there is anyway to utilize smart house controller to signal RadioRa, UPB, HLC or other PLC device, that's the way I'd do it.

The house is using Control4. We were initially going to use a Control4 switch for the towel warmer. The architect decided last minute that the towel warmer should be controlled only through the existing bathroom keypad. There is to be no visible switch - not even back at the distribution panel.

We established that a single gang blank plate is acceptable at one specific location along the wire path, and we have Cat6 wire that we can get to that location. Thus the search for a low voltage controlled relay switching line voltage in a single gang configuration.

My hope is to give the electrician a few relay options and let him figure out the best one for meeting code and making the solution maintainable.

My inclination is that a solution which ships with leads rather than terminals is our best bet. The Leviton looks promising, but sorting through all those skus it a bit of a task.

If you only need to switch one wire, why not hide a Bosch 12V relay somewhere? They cost about $4 and handle [email protected]

Don't let an architect dictate the functionality of the system.
Surely you can find a place in the closet, opposite wall, basement, etc. where you can mount a switch that can be controlled from a keypad.

Tell him it's a code violation to do it otherwise and if he wants to fight the AHJ then that's on him.

Are you sure he's an architect and not an I.D.?

the architect is not dictating the functionality. he is dictating the tradeoffs between aesthetics and functionality, which is what he is supposed to do! if there a place to hide the switch, we would all be happy.

 Is this a towel warmer that plugs in to an outlet? Or is it hard wired? If it's an outlet, you could just use a lamp module on the outlet. 

 Dude, I'm not trying to be difficult, but you can't tell me that there is no place in the whole house to put in a switch. It doesn't have to be close. You've got 75' before you have to upgrade to larger romex, and then...

I don't do C4, but in UPB world there are controllable recepts that would look just like regular receptacle but one (or both) outlets are controllable.

This is a tough situation because you have to force folks to do it correctly and legally and they don't seem to want to.



There's this joke: why can't an architect get into heaven? Because Jesus was a carpenter. Every GC I've ever told this to laughs because they know the truth -- the architect has vast ideas but only half-vast (say that out loud) understanding of what it takes to do his ideas.

Cooperate fully.  Propose to do exactly what the architect wants. COST the ripping up of the wall to get the LV section of a transformer on the outside of the existing box (we guess it's existing -- you don't say). COST all the labor involved.  COST out the labor you've put in on that function up to this point that will become a complete waste when you do what the architect wants. COST the redesign and the search for parts to do it. Point out apologetically that, as everyone knows, it costs much more to make a change like this late in the game, and you're sorry that you have to tell him how much more it will cost to implement this really cool feature.  But it WILL cost more and you will bill him for it and you expect to be paid the upcharge before you do the work.  After all, the architect has already shown that he is willing to spend more of the client's money after the client knows the price, and you have to insure that you get paid for any raise in price the architect feels he needs to introduce.


Idiot Deviant.  Yup.

"not even back at the distribution panel."

Why would that be a problem?