COMPRESSOR SWITCH L1 and L2

[Clik]

I have a 5HP 240 Volt Air Compressor I'm hooking up.

The switch's connections are labeled L1 and L2.

The compressor instructions read Black to Black and White to White.

The wires in the wall outlet are one ground and two black wires but one of the black wires is marked with red paint.

If hots can be switched why would the electrician have marked one of the hots red?

Why would the directions read: Black to Black and White to White if they can be switched and it doesn't matter, as some say?

Do I need to determine which is L1 and L2? How?

 

[American Locomotive]

It is so you can identify which wire is which back at the breaker panel. Generally the wire should be red and black for 240v hot legs. In 4 wire 240v circuits, the white is neutral and cannot be interchanged with a hot leg.

But, many people just run standard 3 wire nm-b (2 hots, ground) which have white and black wires for 240v 3 wire circuits, and most cables only have white and black.

 

[yatg]

Why would the directions read: Black to Black and White to White if they can be switched and it doesn't matter, as some say?

Because those are poor directions. As long as you have 240v between your wires, whatever color they are, it doesn't matter which one you connect to L1 or L2 on your 240v motor.

 

[Bert_]

It doesn't matter. I hate electrician's who phase tape on single phase. What a waste of time

 

[The Cobbler]

at 240 you don't need to worry about it.
often those switches are used in 120 and the neutral is switched, then you would pair the terminals up

 

[Clik]

Thanks all.

 

[AntonLargiader]

That's a pretty petty reason to hate someone, for spending a few seconds to clarify which wire is which. I know you're not really serious there, but still. That electrician thought it might be handy to know in the future; what's the huge harm in that?

It doesn't matter. I hate electrician's who phase tape on single phase. What a waste of time

 

[Bert_]

That's a pretty petty reason to hate someone, for spending a few seconds to clarify which wire is which. I know you're not really serious there, but still. That electrician thought it might be handy to know in the future; what's the huge harm in that?

Your right that I don't really hate them. But phase taping on single phase is never useful. It's a waste of time. There is no phase rotation and they are both the same voltage.

 

[sberry]

It's due to the use of cord. I tape whites in panels when cable is used 240. Just a reminder and to avoid confusion for future diy types.

 

[pattenp]

Your right that I don't really hate them. But phase taping on single phase is never useful. It's a waste of time. There is no phase rotation and they are both the same voltage.

It's due to the use of cord. I tape whites in panels when cable is used 240. Just a reminder and to avoid confusion for future diy types.

For one thing the NEC requires the remarking of a white in a cable at the terminations when used as an ungrounded conductor. NEC 200.7(C)(1)