PM-1660TL

You may just put a disconnect box on the machine.

I have disconnects on the walls for all my large equipment and then they have disconnects on the machines aswell. That is more of an industrial type setup though. If you really want a disconnect. One for your lathe can be had for maybe $30 if you can’t find one for that price let me know and I’ll send you one as I have a 30 amp one laying around that I don’t particularly need I was gonna put it on my grinder but haven’t decided yet so if you need it I’ll send it that way and buy a new one later.

You’ll still need your breaker but this is just an industrial on off switch. Fused ones are available aswell. Once again not needed but I fuse and breaker all my machines just because.
 
Ianagos said:
You may just put a disconnect box on the machine.

I have disconnects on the walls for all my large equipment and then they have disconnects on the machines aswell. That is more of an industrial type setup though. If you really want a disconnect. One for your lathe can be had for maybe $30 if you can’t find one for that price let me know and I’ll send you one as I have a 30 amp one laying around that I don’t particularly need I was gonna put it on my grinder but haven’t decided yet so if you need it I’ll send it that way and buy a new one later.

You’ll still need your breaker but this is just an industrial on off switch. Fused ones are available aswell. Once again not needed but I fuse and breaker all my machines just because.
Click to expand...

Could you please upload a picture of such a disconnect, please? Is that one of those levers that you throw?
 
erikmannie said:
Could you please upload a picture of such a disconnect, please? Is that one of those levers that you throw?
Click to expand...

This is similar to what I got

c6d4fea4ca300964b0c65bcdc6317f72.jpg
 
I work out of a very large warehouse & we use the circuit breakers in the breaker box to turn the lights on & off. I wonder why I can’t just use the circuit breaker for an on/off switch.

This article has something to say about that:

c3controls

The best electrical controls business on the planet!
www.c3controls.com www.c3controls.com

Simply put, A circuit breaker is not designed for as many cycles as a switch. Using it as an on/off switch risks prematurely wearing out the circuit breaker.
 
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erikmannie said:
I work out of a very large warehouse & we use the circuit breakers in the breaker box to turn the lights on & off. I wonder why I can’t just use the circuit breaker for an on/off switch.
Click to expand...

This was brought up in a VFD thread sometime back. Apparently circuit breakers are not made for frequent switching and using them as an on / off switch on a daily / semi-weekly basis will lead to a very short life span (compared to an actual switch).
 
Since I am so short on money, time & space, I think I will have the lathe unplugged while turning the RPC on, and then plug it in.

The warning (that came with my RPC) regarding starting the RPC with a load on it is interesting. If somebody has 3 phase service (from the power company), they can plug the machine into the wall & immediately get 3 phases, all with stable voltage.

In the case of an RPC, when it first starts you get 2 (natural) phases with stable voltage, but there is a short time in there where the manufactured leg must vary wildly (pun intended).

This manufactured leg probably starts at zero Volts when the RPC is turned on, as the RPC motor needs some time, albeit very short, to get going and do it’s thing. Also, the capacitors can’t possibly charge & discharge instantaneously.

So the wild leg during this very short period of time at startup could cause trouble ($$) in an expensive machine; even so, I am sure that a lot of people start the RPC with their machine plugged in and never suffer any ill effects.
 
So a few suggestions on the above discussion, first when you turn on the RPC, the wild leg is not powering anything on your lathe, it is only used when you run the motor. So there is no harm in powering up the RPC with the lathe connected, the transformer is connected to the line connections, it draws very little current. Breakers are not a good form of routine disconnect but can be used as a disconnect. There are also some variations as to the type of breakers used, so I do not see a problem using the breaker should you want to keep the RPC running and want to power down the machine. I do not see using the plug as a daily form of a disconnect as a practical solution, it will most likely wear out long before the supplemental breaker wears out.

As far as power disconnects, the easiest solution is to get a power disconnect switch and mount it on the side of the lathe cabinet. All 3 phases come in and go to the switch and then to the terminal strip power they are currently connected. You would need a 30-40A rated switch, they are an easy install. See example below, but in the meantime I would use the breaker on the RPC if you need to disconnect power to the machine with the RPC running. Otherwise I would just power up the RPC and just not run the lathe until the RPC is up and running which is almost instantly. A rotary panel mount power disconnect switch is around $30 plus shipping, example below.
motorsandcontrol.com

WEG Electric (MSW 40 P3 N-H), 40 Amp, Non-Fusible Disconnect Switch (Includes Handle Red/Yellow)

Large WEG Electric Stocking Distributor. WEG Electric (MSW 40 P-3 H), Non-Fusible Disconnect Switch (Includes Handle Red/Yellow), Door Mount, 3 Pole, 40 Amps
motorsandcontrol.com motorsandcontrol.com
Power Disconnect.jpg
 
@mksj Super helpful! I can trudge along with what I have until I get time & money for a disconnect.
 
I would be very surprised if your lathe didn't have a main disconnect built in. It will most likely be near where the power goes in. Mine is on the back of the left end of the lathe down low. Red handle. The electrical control box has the motor overloads so you will want to become familiar with them in case one gets kicked out and you have to reset it. I have a PM1440HD and that's where it has the main power switch and motor controls.
Watch Joe Pie videos of him using the lathe. He has installed a switch on the lathe to remotely start the RPC. You can hear it start just before he starts the lathe. He shuts it off when he is trying to talk because of the noise it makes. I don't think you need to disconnect the lathe when starting the RFC just don't try to start it at the same time or have the operating handle in the on position. The RFC will come up to speed very quickly, a few seconds. Your RFC probably has a magnetic pickup coil, if it's not 24V you can change it and add a little transformer so you can run small wires W/O conduit to a start/ stop station on you lathe. Takes 3 small wires. If you get more 3 phase machines you can just keep adding to the remote start stop wires, chaining them all together. The off circuit is series switched the on is parallel. Simple & cheap.
 
erikmannie said:
In the case of an RPC, when it first starts you get 2 (natural) phases with stable voltage, but there is a short time in there where the manufactured leg must vary wildly (pun intended).
Click to expand...
I put in a 10HP American Rotary RPC. The first time I hooked it up to one of my 3 phase machines I checked the voltage, 120-120-236 #$%^&????
When I turned on the surface grinder, I checked the operating current again, 120-120-122. ( or something close to this)
I don't get it. I don't need to get it. The mill, SG and lathe all run off the RPC with their own disconnects next to the machines. I use the on-off switches that came with the machine tools.

I sure do like your lathe Erik. That is one you will use for life. Don't worry about the money, you can always make more :)
 
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