2 motors on 1 VFD question

DaveMartell

DaveMartell

Joined
Apr 22, 2010
Messages
235
I've got a KBAC 27D VFD and a 1HP 3phase motor

I want to buy a 1.5 HP 3phase motor for use on another machine but would like to use the current VFD to run both. Is this possible?
 
Yes it is possible if the VFD is rated for 1.5 HP.
The easiest way is to buy a 3 pole switch and put it between the motors and VFD.
Turn on the switch for the motor you want to run.
Dan
 
The VFD is rated for 1.5HP but there's a jumper inside that has to be set to either 1HP or 1.5HP......which would be chosen?
 
VFD's really don't like to have their loads disconnected, it can cause voltage spikes that will fry the VFD.

You can wire in a 3PDT switch, or a DPDT and keep a common conductor between the two. a 3pole barrel switch is your best bet.

Make sure it is never disconnected hot. Use the 1.5HP jumper and make sure you don't overheat the 1HP motor, it shouldn't be a problem but the VFD won't shut it down BEFORE it's gone.
 
Just bought a TECO FM50 for 3 H.P. I plan to use the switching box with the 3P2T switches. My current KMG grinder is running a 1.5 3ph motor and my EF-48 has a 1 HP motor and I plan to also connect a 1.5 HP motor for a 9" Disk Sander. From what I understand is that the 3HP FM50 should run either motor without any overheating issues. Is this correct or do I need to re-order the one rated for 2 HP?

Jeff
 
I just use plugs. One female and as many males as tools I have. When i want to change tools I just unplug one and plug in the other. I make sure they are off and stopped before I switch but other than that no issues. It can be kind of a pain but it is an easy way to do it. The 1.5HP VFD will run the 1hp and 1.5 easily. Mine is a 3hp and I have run .5-3hp motors on it. Some harder start tools did not like it ie my surface grinder. I ran that on a static converter until I got the Rotary.
 
I have the Teco FM50 203, that is the 3 hp model. I run two three horse motors and one 2 horse motor on it, no issues. No jumper to mess with. I use 3PDT on/on switches to select machine.
 
Dave, I used the multiple plug approach to connect my 1.5 HP Disk grinder and 2HP KMG to my KBAC-27. While it is perhaps less convenient than a switch, it is simpler and more difficult to mess up. -Doug
 
I went with the plugs too at first. Fine for a few days but it drove me nuts pretty fast. I "switched" to the switch and I love it. And it was much less expensive to booth. Easy enough as I got 2 machines running on it. Couldn't tell you how to do it with more than that though. Actually I don't even remember how I did this one. ;) Good luck.
 
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