Electric disconnects

[Rod Sheridan]

Hi folks,

Has anyone here installed a disconnect switch which serves a series of outlets or machines?

I'm looking to run a subpanel for the machines in my shop and would like to install an appropriate disconnect switch between the main panel and the subpanel.

Any recommendations?

Hi Jeff, yes I did that as the kids weren't allowed to use some machines unsupervised.

I used a Klockner Moeller switch that interrupted the 240 volt circuit to the machinery.
KM switch.jpg

[Rollie Meyers]

many years ago using a breaker as a disconnect was not a good idea. However I believe now pretty much all breakers are SWD which means switching duty

SWD rated breakers are most common in 15 & 20A single pole breakers, they are not all SWD rated.

When my shop was built, used two panels, one the back room has the lighting circuits, & receptacles for the back room, the other has all the shop receptacles & the air compressor with a back fed main breaker to shut off all power to the equipment, that panel did not require a hold down/ retainer kit for the back fed main because it was a panel that used bolt-on breakers, plug-in breakers do require a hold down kit when back fed.

[Jack Frederick]

I asked my electrician about this when I built the shop. He asked if I was going to do this every time I left the shop. I indicated that it would be used when I was away from from home at work or holiday. He said the breakers in the panel were sufficient for that use and I have used them that way without problems.

[Andrew Seemann]

I asked my electrician about this when I built the shop. He asked if I was going to do this every time I left the shop. I indicated that it would be used when I was away from from home at work or holiday. He said the breakers in the panel were sufficient for that use and I have used them that way without problems.

I turn off the 60A breaker for my machine subpanel every time I leave the shop for the day, with no problems for the last 7 years. The only load on the breaker when I turn it on and off are a couple of task lights with LED bulbs (probably 20 watts total) that I leave on so I can tell if the power is on to the machines. I anticipate that 60A breaker will last for many years to come.

[Curt Harms]

If I had intention to cut power from a typical shop, with a reasonable load connected, I would prefer to use a contactor, an electrical relay, using NO (normally open) contact.
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If someone's shop is such that lights are always on, using an appropriate contactor controlled by the lighting circuit seems like a good idea. No lights, no power to machines. I've also heard of using a keyed switch to control a power relay.