Can you use a 48V 10kW Motor with a 72V VEC500?

[TTrotter]

Hi Alan,

New member question please? Would be good to get confirmed too please? :-)

For other reasons, I've had to upgrade my project (a David Brown tractor conversion) from 48V to 72V. I've now got a 72V VEC500 controller to replace the 48V VEC500 I had, but do I need to replace the 48V HPM-10kW motor with a 72V one too? Or, can the 72V VEC500 controller be programmed to run the 48V motor?

Thanks in advance for your replies.

[Bikemad]

Hi andto the forum.

Your 48V 10kW motor should still work OK with the 72V VEC500 controller, although the maximum rpm of the 48V motor could theoretically be 50% higher with a 72V battery than the 72V 10kW motor (assuming the programming software will allow it).

If you intend to utilise the higher motor rpm, it's probably a good idea not to exceed 6,000 rpm for the Rated motor speed (rpm) setting to ensure the magnets bonded to the rotor are not subjected to excessive centrifugal/centripetal forces which would be experienced at higher motor rpm.



Your account has also been Confirmed. 

Alan
 

[TTrotter]

Thanks, Alan.

I was concerned that the phase resistance is different for each motor  - "Phase Resistance (Milliohm): 3.1/48V; 6.0/72V; 18.0/120V", so almost half the resistance on the 48V motor compared to what the 72V controller might be expecting. Hopefully the controller self compensates, or can be programmed to support this.

Will give it a go at low speed - low load and see how it goes...

Cheers.

[TTrotter]

Just closing this thread off: I went ahead and tried the 72V VEC500 controller (running at 72V) with the 48V 10kW motor and it seems to work fine - so far so good anyway.

Btw, I didn't need to buy a 72V VEC500 controller after-all. As I tried reprogramming my 48V VEC500 controller, changing it to 72V, and it works fine too.

So happy camper