# 2 AC Controllers 1 motor?



## skullbearer (Jul 9, 2008)

neal said:


> First post guys, I've been all over this site trying to learn as much as possible from the knowledgeable members. I am considering an EV build. I am not an EE so please don't bash me. I like the efficiency and "percieved refinement" of AC systems but they are ^$. So my question is... Can I use 2 or possibly 3 Curtis 1238 84 V 500A AC controller each with a string of 84V battery packs and feed them to one motor ( assuming I can find the correct motor). Does 84V + 84V + 84V = 252V or is 84v + 84V+ 84V = 84V at a different AMperage. Thanks in advance guys....


In regards to your V vs A question at the end, the answer is _yes.

In series 84V + 84V + 84V = 252V at the same Amp, in this case 500A.

Or in parallel you would get 84V @ 1500A.


As for using two or more controllers, the huge issue with this is the controllers have to be in perfect sync with each other. If you connect two or three out of sync AC sources into a single pole, you are going to get craziness. Opposing sine waves will cancel one another and produce ridiculous heat, and you will have no or very little drive._


----------



## major (Apr 4, 2008)

neal said:


> First post guys, I've been all over this site trying to learn as much as possible from the knowledgeable members. I am considering an EV build. I am not an EE so please don't bash me. I like the efficiency and "percieved refinement" of AC systems but they are ^$. So my question is... Can I use 2 or possibly 3 Curtis 1238 84 V 500A AC controller each with a string of 84V battery packs and feed them to one motor ( assuming I can find the correct motor). Does 84V + 84V + 84V = 252V or is 84v + 84V+ 84V = 84V at a different AMperage. Thanks in advance guys....


Hi neal,

Short answer is no. DC controllers are just buck converters. So can not swing positive and negative on the output as would be needed for AC. And Curtis makes a 3 phase AC controller. Just buy that. Probably cheaper than 3 DC units.

Regards,

major


----------

