Resident Electrician ???

Josh Dabney

Josh Dabney

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Here is my current situation.... Teco TM50 VFD hard wired on a dedicated 220v line.

I'm adding a disk grinder and want to use the same drive to control it. In the future I'd also like to add a horizontal grinder so I'd like to be prepared for that also.

With my limited knowledge of wiring I can think of 2 options

1. Wire a 220v outlet after the VFD and plugs on all of the motors and use a single, movable control box to house the Potentiometer and FWD-OFF-REV switch.

2. Wire a complete set of switches to change from KMG to Disk, then from Disk to Horizontal. The benefits being that each machine would have it's own set of controls and no plugs to mess with.


I'm curious if others have gone this route running multiple machines from a single VFD and how they approached the wiring and if they are happy with the set-up.

Thanks for any replies- Josh
 
I would suggest the plugs Josh . At first I hard wired all my shop equipment and ended up having to undo it all as I redesigned my shop and equipment location . So now every piece of equipment has it's own plug with long cords . Sure makes moving them alot easier .
 
Jack,
That is a very good point. Specifically because my shop itself is still a WIP to a large extent.

Thanks for sharing your opinion -Josh
 
I have exactly the same thing going on so I'm watching.
The plugs would not be at the outlet but after the VFD controller does it's voodoo and converts the single phase 220v to three phase 220v...
 
Tracy,
That is correct. VFD will be creating a "variable speed" Outlet. Just attach a cord and plug to each 3-Phase motor then Plug-n-Play.

I think I'm gonna go this route and stick with a single control box that can just be moved from one station to the other.

I built my grinder bench with this in mind and mounted the motor on the underside of the bench to save space.

-Josh
 
Josh this is exactly what I am going to do. I have a KMG that is fixing to come my way and just about have everything I need to build a disk grind also. I plan to put both on the same controler.
 
Hey Wade,
I don't think we've chatted before but I recognize ya from around town. Holiday today but everything I need for the disc grinder is in route to my house as we speak. I'm hoping to have it up and running in short order so I'll post some pics once I get it together.

-Josh
 
My father in law was the electrcal engineer for General Mills in Joplin. He is helping me with my wiring. I have asked about a couple of things and he has told me the same thing over and over. 220 is dedicated to one thing. No more. Hard wired or plug doesn't matter. 220 is dedicated to one thing. That is all I know. It has been drilled into my head. hope this helps.
 
JA,
I would agree with your father-in-law in the sense that you cannot run a series of 220v outlets from a single 220v breaker the way you would with 110v.
1- 220v breaker= 1- 220v power source that has a single outlet meaning that only item can be connected to that "dedicated" circuit.

I'm fairly sure this was his meaning about it being a dedicated 220

-Josh
 
Cap,
Thats what I had in mind for switching. I was thinking about splitting my motor wires between the vfd and motor.

Too add another motor for a horizontal I would then add another switch between the first switch and disc grinder motor.

Switch 1 = Power to KMG or Disc
Switch 2 = Power to Disc or Horizontal

Relativly simple to wire and use plus no plugs to fool with.

I already have my POT and FWD/OFF/REV wired in a small project box with flexible rubber conduit so I'm thinking that I can build a control box holder at each station and have variable speed on everything with one vfd and be able to switch between machines in less than a minute.


Hope this explains what I had in mind a bit better.
 
Josh Dabney said:
JA,
I would agree with your father-in-law in the sense that you cannot run a series of 220v outlets from a single 220v breaker the way you would with 110v.
1- 220v breaker= 1- 220v power source that has a single outlet meaning that only item can be connected to that "dedicated" circuit.

I'm fairly sure this was his meaning about it being a dedicated 220

-Josh
Click to expand...

I have 6 - 220 v outlets on one 20 amp breaker . I just don't run all the machines at the same time .
 
ONiell,
Good to know that others are doing just that. I had already planned to wire an outlet for an Evenheat on the same circuit as my grinder. I think most electicians would say this is a bad idea though.

-Josh
 
OK yes now I understand and yes as long as you are cutting power with a switch and it transfer over to the other he said he saw no reason it would not work. Sorry about the confusion.
 
Josh , you could still do the outlet idea with the rotary switch just in case you move things around later . soon I am going to change 2 motors in the shop and all I need to do is unplug the suckers .
easy peasey
 
Hi Josh - I think that you could simply use the rocker switch with your vfd and no other switches, since you can shut the power off with the VFD. That being said, a second switch inline on each machine would provide an effective emergency shutoff and help ensure that both devices did not somehow become energized. Also, it might help protect your machinery against a rogue VFD switch, which we've seen a few times.
 
ONiell,
I'm actually leaning toward hard wiring everything and going with the switches. Like many others my shop is part of the attached 2-car garage so when I got my KMG I built the bench big enough to hold the three items and placed it right by the garage door to keep grinding dust as far away from the door to the house as possible so I'm thinking that as long as we dont move to a different house I should be fine and have all my grinding needs in order at the flip of a switch.

Worst case is I end up having to un-wire and re-wire to move things around but my VFD is hardwired and mounted to the wall anyway so I'm thinking the convenience of flipping a switch is gonna be more valuble to me on a day to day basis than ease of moving the grinders.

I do really appreciate hearing everyones opinions so thanks alot to all.

-Josh
 
Cap,
I'm not sure about the "rocker switch" ? My VFD is mounted to the wall behind the bench in a sealed (Home made NEMA) box.

The DPDT switch seems to be the quickest easiest way to me. And like you said, No worries about powering up 2 machines at once accidentally or exposing my VFD to the elements to utilize it's switching capability.

-Josh
 
Hey Josh - I think I was just mis-reading your post above. The DPDT switch is the rocker switch that I was talking about. I think we're on the same page now.
 
AcridSaint said:
Hi Josh - I think that you could simply use the rocker switch with your vfd and no other switches, since you can shut the power off with the VFD. That being said, a second switch inline on each machine would provide an effective emergency shutoff and help ensure that both devices did not somehow become energized. Also, it might help protect your machinery against a rogue VFD switch, which we've seen a few times.
Click to expand...

I see where you are going Josh , but I am with Cap on the second inline switch for each motor . I put dpst 220 switches on every motor .
 
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