[electricvolksie]

Hello,
Does anyone know if the DMOC 445 could run two ac24ls motors? I am trying to do a low as possible budget ev conversion on my freshly restored 78 VW bus. I've found some pretty cheap ac24's on ebay but its looking like one would be underpowered for my ~3500lbs after conversion bus.
Many thanks!

 

[dcb]

nah, generally a bad idea to run two motors on one controller, and the 445 is kinda weak for one motor as it is. If you have a 300V+ pack you can feed one ac24ls in wye with a 445 ok. You will need another 445 if you add another ac24ls. A complete set of leaf modules (or chevy volt modules) would be sufficient to drive 2 445s and 2 ac24ls (in wye), if you are lucky you can find one for a few grand.

Not sure how you are going to connect them to the drive-train though.

 

[electricvolksie]

Thanks for the reply dcb,
Speaking hypothetically if the 445 is compatible with the ac55 which draws 250 amps at ~312 volts and the ac 24 draws 150 at ~336 if the 24's were wired in parallel and connected directly (ie same motor encoder values). Would the dual setup limited at 250 amps give more power to the wheels(through trans) than a single ac24 while staying within the limits of the 445. Or is there other internal limitations of the controller? And further would a DMOC645 be a different story?
Sorry to push the subject!
And thanks again.

 

[dcb]

well, "it depends"...

dual motors on one controller is sub-optimal for a lot of reasons (i.e. field control), especially if you are using one motor per drive wheel. If they are locked mechanically it isn't as bad, but one independent motor per wheel is a nice setup, though keeping the trans is nice in many circumstances too for reasons.

445 vs 645
Maximum Motor Current 280A rms vs 414A rms
http://media3.ev-tv.me/DMOC645_User_Manual.pdf

in delta, my understanding is 400 amps is about as hard as you dare push the ac24ls, so that would be 230A in wye (sqrt(3) thing), so a single 645 is still going to be on the weak side pushing two wye/parallel ac24ls. And typically the 445 can be had for less and is sufficient for a single wye ac24ls. each motor would see 207 amps, so not too far off of 230 amps, so it is probably good enough though, and only if they are directly coupled (and have similiar thermal loading/etc). There are other configurations available as well (i.e. fields in series, overall in delta), but I don't know if the dmoc will like it, but it would retain the 400amp/phase characteristic and allow the dmoc 645 max potential.

Think about how you are going to connect the 2 ac24ls, through the transmission? one per drive wheel? chain? at1200 gearbox?

note, this says 250amps for wye max, so go figure
https://www.google.com/url?sa=t&rct...xylBmjh44YmUj-en8_tPIA&bvm=bv.145822982,d.amc

 

[electricvolksie]

My thought was a direct mechanical coupling like this one by evwest:
http://www.evwest.com/catalog/product_info.php?products_id=441

I'm still a little shaky on the wye/delta thing so to confirm
I've got this right:
Dual ac24ls motor with a dmoc445 -> not possible with either delta or wye
and with a dmoc 645 -> maybe possible with wye?

With that do you know how to tell if an ac24ls is wound delta or wye?

 

[dcb]

here is one way I think 2 ac24ls is possible with 1 dmoc 645, and there is every chance I have no idea what I'm talking about too.

since the 645 max amp is 414, and the max amp of the motor is 400 (assuming you want to push it hard), you can connect the fields of both motors in series, then connect that mess in delta. I have no idea if anyone has done this.
wye in parallel would get you a motor that wants up to 500 amps, and delta in parallel would get you a motor that wants up to 800 amps, and the 645 can only do 414 amps.

But that is all I'm gonna speculate about it. Would be interested to see how you source that motor coupling.

delta/wye is just moving some leads around, in this thread somewhere.
http://www.diyelectriccar.com/forums/showthread.php/azure-dynamics-ac24ls-motors-81166p2.html