240volt lighting ckt (single pole switch)

[winnie]

Doesn't this just apply to the switch itself and not the branch wiring?

I believe so. 240V l-l circuit must be supplied with a double pole breaker.

This is the difference between _controlling_ a load and disconnecting it.

The breaker supplying the load must disconnect it.

But if you are just controlling it the load might remain 'live'.

Jon

 

[mbrooke]

I believe so. 240V l-l circuit must be supplied with a double pole breaker.

This is the difference between _controlling_ a load and disconnecting it.

The breaker supplying the load must disconnect it.

But if you are just controlling it the load might remain 'live'.

Jon

Thats my thinking, the switch is not a disconnect...

 

[growler]

Is this done very often to just open the one “leg” of the 240 to turn the circuit off?

I often wonder why people are that cheap. For a little more money you can buy a double pole switch that will fit in the same box and open both legs.

I will admit that you should always find the breaker and cut that off and lock it out before working on a lighting circuit but some of us don't always practice what we preach.

 

[kwired]

Unless the 240 volts is derived from a 240Y416 circuit and the unswitched leg is grounded. (speaking of oddballs ... )

Oddball in North America, not so much to many other parts of the world.

 

[Dsg319]

I often wonder why people are that cheap. For a little more money you can buy a double pole switch that will fit in the same box and open both legs.

I will admit that you should always find the breaker and cut that off and lock it out before working on a lighting circuit but some of us don't always practice what we preach.

Exactly...

 

[electrofelon]

Exactly...

I would generally install I double pole switch, however if you get into three ways, existing wiring, OC sensors or other situations it may not be so practical.

 

[hbiss]

I would generally install I double pole switch, however if you get into three ways, existing wiring, OC sensors or other situations it may not be so practical.

True. But how many times do you find 240V lighting other than maybe outdoor parking lots. Usually it will be 277.

-Hal

 

[mbrooke]

I often wonder why people are that cheap. For a little more money you can buy a double pole switch that will fit in the same box and open both legs.

I will admit that you should always find the breaker and cut that off and lock it out before working on a lighting circuit but some of us don't always practice what we preach.

A little more money adds up. Plus I'd hate to work on a 6 terminal 3 way switch.

 

[tortuga]

When people buy old factories and convert them to cool fancy 'loft space' here the utility wont bother converting (240 delta) to 208Y120 unless the developer pays for a transformer..
So 240 Volt lighting is common in older industrial buildings here, I think a few commercial streets downtown have it for street lighting for some reason.

I'll never forget the first time I was troubleshooting 240V lighting with out knowing,

Out in the parking lot I had 208 to ground on one leg and a open on the other...
Turns out it was just a bad contactor but had my head scratching.
240 delta interesting stuff, I could go on forever.

The use of a a switch that has a marked "off" position for that application is not permitted by 404.20(B).

I have seen this violation often.

 

[Dsg319]

Thats my thinking, the switch is not a disconnect...

I can see a good point from both directions.
Either way it’s not a wiring method I would ever wanna do, just for the simple fact of who knows the next person that might change out a light fixture assuming all is de-energized.

I know a simple light switch shouldn’t be the only means of de-energizing a circuit (and should be checked) but I myself have been lazy before and relied on-less than safe and proper disconnecting/de-energizing means.

 

[growler]

I often wonder why people are that cheap. For a little more money you can buy a double pole switch that will fit in the same box and open both legs.

A little more money adds up. Plus I'd hate to work on a 6 terminal 3 way switch.

Ok if you were going to use 240V lighting and needed three way switches then the easiest and cheapest way to do it would be to use a two pole contactor with a 120V coil and use the switches to control the contactor. The wiring you would save would more than pay for the contactor.

Don't even consider the voltage drop of running the power conductors through all the extra distance for three way switches. But it could add up.

 

[kwired]

Don't even consider the voltage drop of running the power conductors through all the extra distance for three way switches. But it could add up.

Depends on circuit component layout, and may not add (at any one time) any more conductor to the total length from source to load in some cases.

 

[mbrooke]

How are contractors cheaper than a standard 3 way? Just use a standard 3 way and be done with it. Much cheaper.

 

[mbrooke]

I can see a good point from both directions.
Either way it’s not a wiring method I would ever wanna do, just for the simple fact of who knows the next person that might change out a light fixture assuming all is de-energized.

I know a simple light switch shouldn’t be the only means of de-energizing a circuit (and should be checked) but I myself have been lazy before and relied on-less than safe and proper disconnecting/de-energizing means.

When a person undoes the white splice, what happens when the noodle springs apart under load?

 

[Dsg319]

When a person undoes the white splice, what happens when the noodle springs apart under load?

I know all to well, it was afterwards I learned I became part of a series circuit lol.

I guess there’s somethings you just can’t prevent people from hazards but I like to try my best.

 

[mbrooke]

I know all to well, it was afterwards I learned I became part of a series circuit lol.

I guess there’s somethings you just can’t prevent people from hazards but I like to try my best.

Right, but my point is, unless breaker(s) are open the circuit could be live one way or another.

I know people will disagree, but to me a switch is not a disconnecting device. Its only purpose is just that: on or off, of a load.

 

[kwired]

Right, but my point is, unless breaker(s) are open the circuit could be live one way or another.

I know people will disagree, but to me a switch is not a disconnecting device. Its only purpose is just that: on or off, of a load.

General use snap switches are permitted to be the disconnecting means for many things in the code, they must open all ungrounded conductors when used as a disconnecting means.

 

[mbrooke]

General use snap switches are permitted to be the disconnecting means for many things in the code, they must open all ungrounded conductors when used as a disconnecting means.

Right, when used (applied) as a disconnecting means. In my mind a switch for lighting is control.

 

[romex jockey]

There are some instances like electric heat thermostats where breaking only one side is common. But I would not expect to see it with any kind of lighting circuit.

There's an awful lot of that in my area, never thought it was right.....

~RJ~

 

[kwired]

Right, when used (applied) as a disconnecting means. In my mind a switch for lighting is control.

So they act differently when used on lighting?

There are LOTO accessories that will work with them. Three way and four way sets maybe not a great idea to lock out, unless maybe you confirm the load is not energized and LOTO every switch in the circuit.