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South Bend Heavy 10L wire gauge size for power

upcondor

Aluminum
Joined
Jul 22, 2011
Location
Texas
Recently acquired a 1981 SB Heavy 10L, serial number 22022R. It has a Dayton 1 HP 3 ph motor on it. I am having to run power about 40’. The lathe will be operated with a VFD.

Can anyone help with breaker size and wire gauge size that I would need ?

Thanks,

Tom
 
Regular 12 ga wire with a 20 amp breaker should work just fine. I'm assuming that you are not talking extension cord, but a dedicated outlet with wire run from the breaker box.
 
Yessir, dedicated outlet. Thank you for the info.
Was hoping it was not going to be larger than 10 ga. which I had in stock.
12 ga sounds good.

Lucked out finding the lathe and looking forward to getting it cleaned, primed, & painted....

Definite upgrade from my 9A...

Thanks,

Tom
 
I had to check my serial number as I knew it was close to yours, mine is 22659R.

You could run that little motor on 14awg, but I would suggest paying just a little bit more up front and running 10ga, especially if you're going to the trouble of conduit or other nicer installation methods. You never know when your machines will change and you will wind up with a larger motor, or multiple machines, and have to upgrade later. I had to gut my old wiring and re-do everything when I got a 7.5hp lathe.
 
Well ended up communicating with some YouTube machinist and decided to go with a Lenze VFD. Brad Jacobs and Bar Z “Stan” both have very good videos on installation. Also upgraded to 10 gauge for motor side and also the entire circuit with 30 amp breaker protection. Trying to get this right the first time.

Thanks
 
Read the manual for the VFD you have chosen, it will probably specify an input overcurrent
protection less than 30 amps. Put a fuse in the VFD housing of the correct rating.
 
Ok thanks for info. Can the fuse be the same type used in an auto of the correct size ?

That's how I tend to do it. Fuse holder of the electronics type, visible from the outside, OR a callout
that there's a "FUSE INSIDE" so when it goes, you don't forget and try to troubshoot every other thing.
 
That's how I tend to do it. Fuse holder of the electronics type, visible from the outside, OR a callout
that there's a "FUSE INSIDE" so when it goes, you don't forget and try to troubshoot every other thing.

an automotive fuse won't have the appropriate voltage rating. while the current is the only thing that will heat and blow the fuse it needs to have the ability to avoid arcing in addition, to properly break the circuit. 12V fuses have a short gap, and while it probably won't sustain an arc, why not use a buss type, rated for the voltage?
 
an automotive fuse won't have the appropriate voltage rating. while the current is the only thing that will heat and blow the fuse it needs to have the ability to avoid arcing in addition, to properly break the circuit. 12V fuses have a short gap, and while it probably won't sustain an arc, why not use a buss type, rated for the voltage?

Agree, do not use the blade type. I was suggesting a 250 volt buss fuse in an appropriate holder. Even those
don't have the interrupt spec, but remember this is backed up with a standard breaker with the appropriate
sized wiring. The small fuse is there to protect the VFD from overcurrent, not the wiring. An unusual application
I suppose.
 
Wire your drum switch into the low-voltage controller for the VFD, do not place a power switch inline between the VFD and motor. This will allow you to retain the original operation of the machine.
 








 
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