Running 2 motors on 1 vfd

[Case_D]

I'm a bit illiterate when it comes to electricity, but I want to run another motor off my vfd. I have one setup on my belt grinder currently and want to run a disk grinder off it as well. I saw in another thread that I need some kind of switch for the vfd to switch between the two motors. What piece exactly do I need? I want it to run forward/reverse as well if that makes a difference

 

[Scaniaman]

I'm a bit illiterate when it comes to electricity, but I want to run another motor off my vfd. I have one setup on my belt grinder currently and want to run a disk grinder off it as well. I saw in another thread that I need some kind of switch for the vfd to switch between the two motors. What piece exactly do I need? I want it to run forward/reverse as well if that makes a difference

3 pole 2 position cam switch.

 

[Ken H>]

Looks like this switch will do what you need to do. https://www.amazon.com/dp/B08GS6S5CL/

For the above linked switch (wiring below) the power cable from VFD would connect to terminals 1, 5, & 9, and terminals 1&3 need jumping together, 5&7, and 9&11 terminals also jumpered together. Here is an enclosure for above switch: https://www.amazon.com/dp/B07FJYZLD3/

Motor #1 would connect to terminals 2, 6, & 10.

Motor #2 would connect to terminals 4, 8, & 12

Anybody see anything wrong with above wiring, please correct.

 

[Case_D]

Looks like this switch will do what you need to do. https://www.amazon.com/dp/B08GS6S5CL/

For the above linked switch (wiring below) the power cable from VFD would connect to terminals 1, 5, & 9, and terminals 1&3 need jumping together, 5&7, and 9&11 terminals also jumpered together. Here is an enclosure for above switch: https://www.amazon.com/dp/B07FJYZLD3/

Motor #1 would connect to terminals 2, 6, & 10.

Motor #2 would connect to terminals 4, 8, & 12

Anybody see anything wrong with above wiring, please correct.

Excellent, thank you. I think I can manage this

 

[Jrmysell]

Another option is just run a female plug from the back of the vfd and have male plugs off the motors and swap out that way. That's what I do and havn't had any options. Both grinders are mounted on a harbor freight cart for rolling around with the vfd mounted in between them

 

[SamB]

Ken H's instructions look correct. I'll add two notes:

The first is that you should take care to never change switch position while the VSD outputs are energised, as some VSDs can be damaged if the load is disconnected unexpectedly.

The second is that if possible you should use a motor with the same type and power rating for both machines. If you use different motors, your VSD will need to be configured to use V/F control mode and have the motor parameters set based on the larger motor. However in that case the VSD won't provide overload protection for the smaller motor and you could burn it out.

 

[AKShooter907]

Well, I realize this is an old post, but was wondering if folks have any additional resources for wiring these. The rotary switch,. While I understand the comment, or connection to the motors, I can't figure out were the load in would go. Nor do I see how to deal with the ground.

And maybe that's the clear signal I should just use the 4-prone plug instead, LOL. But just a quick inquiry to see if someone has a wiring guide, or diagram out there.

 

[12345678910]

Well, I realize this is an old post, but was wondering if folks have any additional resources for wiring these. The rotary switch,. While I understand the comment, or connection to the motors, I can't figure out were the load in would go. Nor do I see how to deal with the ground.

And maybe that's the clear signal I should just use the 4-prone plug instead, LOL. But just a quick inquiry to see if someone has a wiring guide, or diagram out there.

Compared to throwing switches, plugs can be a pita


The plugs sure do work "foolproof" but I went to the next size up in plug/receptacle just for overkill and last time I looked those plugs were $40 each

The rotary switch would work and it's physically larger so it's easier to wire.

however Toggle switches work too.
Double throw, tripple pole, Center position off


You don't have to switch the grounds, just wire them all solid to ground.

 

[Scaniaman]

The cam switches come with wiring diagrams. There is no spot for ground in them. Connect your grounds separately using a splicing connector, I like Wago.