New 230V outlets..switched?

[Leon]

My Cabinet saw is portable and moved every time I use it.

[tmbg]

[Biff Steele]

Every 220 in my shop is not a 'plug' in the wall. Instead they are all a short length (14" or so) of flexible 12-3 coming out of the box on the wall. Makes unplugging easy.

It's near impossible for me to reset my planer knives without accidentally hitting the on-switch with my knee. It's just in a bad place so when I set the knife on top, kneel down to test it with the dial gauge, then get up off my knees, my left knee always hits the switch. I've never turned it on but I sure feel better knowing there is no juice present.

jb

[Don Dando]

If MY hands were in jeopardy, I'd open the breaker to the 220 leg feeding the outlets. If you current configuration doesn't allow that I believe I change it. Hands are a rather critical appendage! Keeping power off the machines when repairing or adjusting is only common sense to me.

Don Dando

[RB]

In this application the breaker will not be switching any current so its life should not be impacted. Also, breakers of 30 amps and less don't seem to be impacted when used to interrupt current. Switching larger breakers when carrying large currents can impact their life in my experience.

My personal preference when working on tools that need to be turned off for service is to place the plug on the tool where I can see it before and while my hand is at risk. Maybe I'm paranoid but unplugging it is far more certain than remembering to turn a switch or breaker off.

RB

Roy Smith wrote:

[Greg]

I like the plug in my pocket when I am setting up too ;-)

[Roy Smith]

I don't believe it's the current interruption that causes the wear, it's just the mechanical movement of the internal parts. Circuit breakers (unlike normal switches) are designed to interrupt currents many (like

100's) times their rated capacity. They're also designed to trip even if the external handle is mechanically held in the "ON" position. The design tradeoffs required to meet those requirements usually involve some kind of spring-loaded mechanism, which leads to a relatively high mechanical wear each time the machanism is cycled.

If the contactors can handle interrupting a 1000 A overload, the arcing caused by interrupting a 20 A load isn't going to be significant.

There's no doubt that that's the safest way to do it.