Powerflex 70 Trainer

[hooter32]

I came across a spare Allen Bradley powerflex 70 vfd. There are several guys in the shop interested in learning how to program and troubleshoot these things. i was wondering how they set up the suitcase trainers. Is there a transformer or can it run off 120vac. I am also wondering what is the voltage on the smaller motor it turns. Has anybody ever set up one as a trainer/demo?

 

[Ken Roach]

I know you can set up the small PowerFlex 70's to run from single-phase 240V or 460V. There's a control power transformer in the demo that's wired up "backwards" where 120VAC is on the "Secondary".

Only the very small PowerFlex 4's can (in my recollection) actually be powered by 120V single phase.

The motors, though, need to be either 240VAC or 460VAC three-phase motors. You can certainly turn down the current limit to match whatever small motor you connect.

 

[leitmotif]

I have a suitcase type trainer using two GE circa 1985 drives. I have learned a lot from it and it has paid for itself many times over. I removed motor and mounted on simulated vehicle for use in teaching electric vehicle AC drive class. Bought from a fine gentleman on this list. I will leave it to him to identify himself and his willingness / ability to sell another.

Recommend this idea very highly.

HOWEVER
I think you guys may just be better off to set up your spare VFD for what your needs and wants are. Yes reading the manual and then figuring out how to wire it is a PITA but all good learning is hard at first = BUT it stays with you.


What is rating of VFD??
IF designed for 230 (460) 3 phase you can run off 230 (460) single phase but derate by 50%. Match motor voltage and rating to that of VFD (derated if needed).

Dont worry about all the bells n whistles in my opinion. Get it to run with basics ie stop start reverse and variable speed control -- make sure you have right size dynamic brake resistor (it may be built in). It may be handy to have a DC voltmeter to monitor DC bus voltage - I want to put one in on mine to better illustrate dynamic braking.

For load I think a hoist type affair is great. You can vary load, speed, direction, show motor freewheeling when in overhauling, show dynamic braking.

IF a V/F only unit ie without encoder and catch on fly DO NOT try to control when freewheeling or coasting just turn VFD off. So far I have gotten away with this mistake.

Dan Bentler