Reversing grinder direction?

[gi_984]

I have a 3 phase Rockwell Delta 7 inch pedestal grinder. Picked it up from a high school auction. Only issue is it runs backwards. It has a 4 wire plug:

X- Black
Y-Red
Z- White
Ground-Green

I should only have to switch the Black and Red wires to reverse the motor correct?

It has been years since doing any electrical work and just need a sanity check from the group to make sure I'm not overlooking something obvious.

 

[JimDawson]

You are correct, interchange any 2 of the power wires! Either that or turn the grinder upside down)

 

[gi_984]

Hi Jim, thanks for the sanity check. It was one of those moments where I was just going to do it and stopped to realize it wouldn't hurt to ask. I had a image of a motor with smoke coming out of it!
Turning it upside down is always an option. Kind of hard to hold the HSS bit in one hand and the grinder in the other.

 

[Ulma Doctor]

i wire every 3 phase plug like this:

green is ground, attach it first.
white goes directly opposite of green, attach it second.
red and black are the wires i switch to reverse motor direction.
i will install the wires in the plug and test rotation-
if your luck is anything like mine, the motor will be running backwards
(even if i don't trust my initial feelings and use reverse psychology , that choice is invariably incorrect too :banghead
you'll simply swap the red and black respectively, reassemble the plug and you are done!!!

 

[gi_984]

I actually wrote that down in my shop notebook. I reversed the wires and presto! Runs great.