What is the name of the 3 phase switch I need

I have a phase converter that ranges from 3 - 7.5 hp. It is currently running a 3 hp jointer. I am in the process of acquiring a 5 hp 3 phase bandsaw. I have a one man shop and do not intend to ever have more than 1 machine on at a time. But for the sake of eliminating any chance of ever having both machines on at the same time and overwhelming the converter, I want to run out of the converter and into a switch that "redirects" the circuit to either machine. This would prevent both machines from being able to turn on at the same time. The switch would not necessarily need an "off" position.

After trying to find such a switch, I came across 3 phase rotary changeover switches, but I am not sure if they will accomplish what I am after.

Does such a switch exist, and what are they called?

You might be describing a manual transfer switch. These are commonly used in generator and UPS configurations to select the source of power for a common output. The manual two-position 3-phase transfer switches we use are simple make after break mechanical contacts.

thanks. I looked those up and they are larger / more expensive than I was expecting at $150+. Could these be considered a triple pole triple throw switch, as this is what I think I am in need of?

I would not go this route, but don't see why I could not theoretically use a junction box with 3 20a single pole double throw switches, one leg of 3 phase going to each, and switch them all at once manually. This could be achieved for $25, which is much closer to what I would have expected to pay for such a switch, unless the search results I am seeing are not what I am after...

Run the converter to a lug only 3phase panel.

The manual transfer switch would work but I wonder about the cost of materials and installation time being worth it. If you're the only person in the shop, why not put a sign over the ON switch of each machine reminding you to turn one off before turning the other on? And what are you going to do if you add another machine? Then it gets even more costly. I would use the reminders over a transfer switch and I'm an electrician. Just my two cents...

It sounds like you want to hard-wire each machine (or at least use dedicated plugs for each). If you don't think the reminders, or swapping plugs into a single 3-phase receptacle will work for you, you might find a deal on a reversing motor starter. Not sure if you're familiar, but it's typically a pair of starters with a common feed, a selector switch, and a common output (just with a phase swapped - depending on which starter is energized).

Wire your phase-converter to the input, remove the old 'reversing' output wiring, and split the respective starter's outputs to each of your 2 existing machines. Re-label the FWD-REV switch to reflect your machine selection. ....This doesn't expand very easily if you ever add another 3-ph machine.

Another alternative is to interlock the coil of one machine to the starter of the other. If one is running, the other won't start. It is a simple concept, but perhaps over-kill for a home shop and hard (for me) to briefly explain here. If you're interested, let me know and I'll see if I can explain or point you to good info resource.

Dustin,
you could always wire the machines through a 3 pole toggle switch like this

https://www.automationdirect.com/adc...rollers/30003D

I will probably go the "sign" sign route. I thought that it would be good insurance if the switch I was after was simple/cheap. thanks everyone for the responses.

One simple approach is to only put one receptacle on your phase converter. You would have to physically unplug one machine in order to plug the other one in.

Steve

You won't overwhelm your RPC. though a bit counterintuitive, running a motor off the RPC will actually increase the capacity a bit. It's common practice with hard starting machines on a marginal RPC to start a smaller motor then start the hard load.

Mike

My son in law wired my g0766 and it still doesn't make any sense to me how he managed to provide me with 220. He cut the plug off of the lathe's power cord and replaced it with something else.
I guess that's why he gets payed the big bucks:confused:
Said when I get my shed/workshop he'll do it different????

The cheapest solution here is also the best: don't worry about it. As Mike mentioned, a RPC can handle larger loads than it's idler motor rating, as long as the loads are within the starting capacity and are not started all at once.

I agree that you won't have a problem .. The Band-saw running without wood won't be enough to stop the 3hp motor from starting.

The only machine I ever forget to turn off is the planer, ( Cant hear it with DC running ) . Leaving saws running is much more obvious.