one way to use a three way switch

[frizbeedog]

This is genius, I think this is one of the most creative ways of using a circuit to it's full potential. Does anyone see a violation here ? I don't.

Thanks, now I feel smart. :smile: That ain't so easy around here.

 

[jrannis]

I dont see a problem, When I did residential service work I would only stock 3 way Decora switches. It cut down on some inventory.
Ive seen 3 ways and 4 ways used on all kinds of master switching lighting circuits. Its not for me but some guys used to really get into that stuff.

 

[Minuteman]

Used a 3-way on the lights at a beauty shop and closed sign. One way, the lights are on, the other, the closed sign is on. Hey - it's what she wanted. :grin:

 

[acrwc10]

Oh! The Humanity!

Anyway,


One could argue (I know this because I have ) that it does not relieve any of the requirements of 210.23, since the circuits are still connected to the same OCPD. Other esteemed members disagreed with my argument.

HYJACK TIME
Well now I have to get my 2 cent's in on this one George, 210.23 Permissible Loads.
In no case shall the load exceed the branch-circuit ampere rating.
The load is only connected when the switch is connected, so at no time can both loads be connected at the same time. The same logic must apply to a transfer switch, if you use your way of thinking about it you could not use a transfer switch on a service because both are connected at the same time. So my friend from South Park Co. what say you to that?:smile:

 

[George Stolz]

The load is only connected when the switch is connected, so at no time can both loads be connected at the same time.

I am well aware.

I'm simply stating I don't think the code language has a hole in it for this practice.

Look at 210.23(A)(2):

(2) Utilization Equipment Fastened in Place. The total rating of utilization equipment fastened in place, other than luminaires (lighting fixtures), shall not exceed 50 percent of the branch-circuit ampere rating where lighting units, cord-and-plug-connected utilization equipment not fastened in place, or both, are also supplied.

We are told to examine the branch circuit OCPD, and the rating of the appliances involved, and compare. There are no allowances for interlocked equipment, as there are in, say, 440.33 exception 1.

I'm not saying there shouldn't be such an allowance, but there currently isn't one, to my knowledge.

The same logic must apply to a transfer switch, if you use your way of thinking about it you could not use a transfer switch on a service because both are connected at the same time. So my friend from South Park Co. what say you to that?:smile:

I'd say you have a valid point, but it would take a very flexible perspective to call the threeway switch described a transfer switch - two loads versus two sources.

I stood in there and argued this last time, so I think I'm probably going to leave it at that. I think that 210.23 should have an exception for interlocked equipment, IMO. Then everybody wouldn't be mad at me for thinking the way I do.

 

[iwire]

George IMO I do not have to count the load that is not connected. I do not need a loophole for what is IMHO straight forward common sense. :smile:

Much like I don't have to count the unused traveler as a CCC. (You already proved that )

 

[Dennis Alwon]

Sorry George, I have to disagree with you but more importantly who do you know that you were able to change your forum name.. Now I have to pause when I say your name. :wink:

 

[George Stolz]

Sorry George, I have to disagree with you but more importantly who do you know that you were able to change your forum name.. Now I have to pause when I say your name. :wink:

I was referred to for the 400th time in the third person as georgestoltz instead of just George or something along those lines, so I pulled some strings. Over time, we have referred a slew of people who had registered with their email addresses as their usernames to the Changer of Names, so I slipped mine into the stream too.

George IMO I do not have to count the load that is not connected. I do not need a loophole for what is IMHO straight forward common sense.

I knew you'd be coming.

One fellow's signature around here states that "nowhere in the NEC are the words 'common' and 'sense' in the same sentence."

I'd just as soon the NEC were very clear about everything, as much as they can. I think I've got a little room for this interpretation, IMO.

Much like I don't have to count the unused traveler as a CCC. (You already proved that :wink

I vaguely recall something along those lines. Did I submit a proposal to that or something (proved it the more publicly embarrassing way? )

 

[iwire]

OK lets try this.:smile:

How close to the building does the appliance have to be before I have to count it in the service calc?

If I have spare unused appliances in my garage do I have to count them?

How about if I store them in my basement?

Well those are both full so I store it in my kitchen. Now do I have to count it?

No, it does not count until I connect it, and the switch prevent both loads being connected at the same time.

Now maybe I would need a code section allowing me to connect both units and interlock them with a control circuit but that is not what the SPDT switch is doing, it is disconnecting one or the other appliance.

I vaguely recall something along those lines. Did I submit a proposal to that or something (proved it the more publicly embarrassing way? )

I think that section was less clear and I am thankful you put in that proposal. :smile: At least now we have something we can point to and say we have clue.

 

[George Stolz]

Good analogy. I'm still not budging.

No, it does not count until I connect it, and the switch prevent both loads being connected at the same time.

When you look at the appliance, plugged into the wall, is it connected to the premises wiring system?

It looks that way. Is it electrically? Arguably not, I suppose. But on the spot, with an inspector on site, I would have a hard time selling that argument, IMO.

Now maybe I would need a code section allowing me to connect both units and interlock them with a control circuit but that is not what the SPDT switch is doing, it is disconnecting one or the other appliance.

Are you showing me a chink in your armor?

I think that section was less clear and I am thankful you put in that proposal. :smile: At least now we have something we can point to and say we have clue.

I didn't remember that hardly at all, I just went and looked. As most of mine did, it had a nice fat "Reject" on it, but I'm with you, it's good to have something to point at.
View attachment 1655

 

[frizbeedog]

I'm simply stating I don't think the code language has a hole in it for this practice.


I think that 210.23 should have an exception for interlocked equipment, IMO. Then everybody wouldn't be mad at me for thinking the way I do.

Holes were meant to be filled by ingenuity.

...and no one is mad at you.

I've used this method only in existing situations. A safe way to meet a particular need. Wouldn't really consider it for standard practice.

George, If we had that exception, how many ways can you think of that it might be used and would you really want it to?

 

[quogueelectric]

Plus $20 in gas and an 1+ hours to and from supply house + waiting at supply house.

Are you telling me you dont stock basic switches on your truck for 50 bucks?? standard white ivory almond, decora white ivory almond??

 

[iwire]

When you look at the appliance, plugged into the wall, is it connected to the premises wiring system?

No, not if the SPDT is open to that appliance.

Are you showing me a chink in your armor?

No, I firmly stand fast on the use of the SPDT switch.

 

[masterinbama]

I use three ways all the time in darkrooms up is safe light down is work light

 

[jrannis]

installed for a short time in the 60s we used to see waterheater and clothes dryers next to each other on double throw switches

 

[acrwc10]

installed for a short time in the 60s we used to see waterheater and clothes dryers next to each other on double throw switches

Now that is a bad idea, if you forget to throw the switch back after doing the laundry it's a cold shower for the next morning.

 

[nyerinfl]

Are you telling me you dont stock basic switches on your truck for 50 bucks?? standard white ivory almond, decora white ivory almond??

The argument was for when you have the 3-way, but don't have the single pole. Obviously if you need a single pole, and were in posession of a single pole you wouldn't use a 3-way. You've never been on a call where you were missing something you probobly should've had so improvised?

 

[mdshunk]

On a related note, here's something I drew up a few years ago for a post on a DIY site as a replacement for those crappy ON-OFF-ON whole house fan switches:

 

[mattsilkwood]

Used a 3-way on the lights at a beauty shop and closed sign. One way, the lights are on, the other, the closed sign is on. Hey - it's what she wanted. :grin:

ive seen the same thing on an open closed sign

 

[iwire]

Nice Marc.

I did the same for an exhaust fan in Dads garage but I used two devices, never thought about using the single device you show.