Dual drive with shared line reactor question.

I've got a design under way that will have a 40hp motor and a 5hp motor on drives. The motors are mutually exclusive, they don't run at the same time, but both drives are powered up at zero speed at the same time, and the swich between stopping one drive and starting the other is just milliseconds. I'm thinking of putting both drives under one line reacotor (sized for the 40HP drive) and I can't forsee any problems... but I've never done that before and thought I'd ask the board about any bear traps to watch out for?

The reactor will have to be sized for the combined input current of both drives but otherwise you should be ok.

Watch out for voltage drop problems tho. Remember that a 5% line reactor drops 5% of its source voltage at rated current, a 3% reactor drops 3%, etc.

If you're only starting with 460V, you are going to be a bit low at the drive.

Thanks DickDV, I was hoping you would respond. That's pretty much what I thought. I was mainly looking to conserve some needed panel space but I had never done it this way before.

Just posting an update on this thread.

Once I got the dimensions and laid it out, this doesn't save any panel real estate at all. Using a shared reactor will require branch circuit protection before the reactor, then branch circuit protection to each drive after the reactor. The line reactor for the 5hp drive has virtually the same footprint as the breaker.

Also, two reactors + two breakers costs less than 1 reactor + three breakers.