Can 2 grinders/motors be hooked up to the same VFD?

rtj1981

rtj1981

Joined
Dec 2, 2005
Messages
157
I'm looking to get another grinder and was wondering if I can put it next to my current one and use the same VFD. I thought I read somewhere you can't, but I can't remember where I read it or the exact reason why. Thanks.
 
I saw a thread were someone had 3 hitched up, they did it with a switch on the output side and just turned the switch to what ever machine they wanted to run
 
If your VFD has horsepower jumper settings, you have to use the same size motor for both.

I have plugs too.
It is slower than switching, but more flexible if I need to move anything.

I have the ability to have an unlimited number of plugs on standby, no limits to adding new equipment...

It would be nice to have a VFD on Every machine, but I will usually find something else to spend $ on.

If I need to test an used 3 ph motor that I just bought, I just have to wire it up to a plug and plug it in.
 
Patrice Lemée;8907299 said:
I have to look into what a switch would mean, cost wise. I am tired of using the plug setup. :(
Click to expand...
I have $20 invested in my setup.
$16 for a 3 Pole, Double Throw switch.
$4 for a cord grip to get the second motor wire into my VFD
 
Brian, anymore info on the wiring and such would be great. As I said on another post, I am so dense when it comes to anything electrical. :(
 
A 3 pole double throw switch has 9 terminals on it.

Instead of feeding straight from the VFD output to the motor, your 3 wires feed from the VFD to the 3 terminals in the center of the switch.
Three wires from each motor feed to the appropriate terminals on either end of the switch.
That's it, the whole deal...

In one position, one motor is fed power, in the other position the other motor is fed.
Ground does not feed through the switch.

I use an On-On switch rather than an On-Off-On switch just so power is always fed somewhere.

On my KBAC-27D, there is a blank switch hole for an auto/manual switch, and I just put this switch in that spot.
2 motor cords and a power cord feed in to the VFD, there's plenty of room.

The same could be built into an external box, if using a less friendly VFD.

I used a 15a switch from McMaster-Carr #7343K862
 
No problem man.
It's not a common switch, not something you find at the local home improvement store...

An electrical supply house might have them though.

I could probably take a picture tomorrow if needed, but it would just look like a bunch of wires on a switch...
 
Last edited:
Brian Fellhoelter Knives said:
No problem man.
It's not a common switch, not something you find at the local home improvement store...

An electrical supply house might have them though.

I could probably take a picture tomorrow if needed, but it would probably just look like a bunch of wires on a switch...
Click to expand...

Digikey is a good electrical supplier
this is in stock
free shipping if you spend $200, otherwise $ 8 flat rate charge shipping for anything.
(I hate paying shipping, but I cant drive anywhere for $ 8

They do have a Canadian site so Pat you have no border charges

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=S33T-ND



S33T-RO.jpg
 
Thanks for the offer Brian but no need for a picture. Sounds simple enough, even for me.:o

I have an electric supply store not too far from here. I'll give them a call tomorrow. If they don't have it I'll order one with your link 123.., thanks.

You guys rock! :thumbup:
 
You are indeed correct.

Mine say they draw about 6 amps.

I was just pointing out something that may not be obvious to everyone...
 
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