# dual motor series connection



## GerhardRP (Nov 17, 2009)

glaurung said:


> Hi,
> I have now been "driving in" my dual motor on parallel and would like to try series.I could not find info about connections but i figured it would be like this.
> On parallel D2 goes to A2, +to D1 -to B1 and same to other motor.
> Series would be D2 to A2 on both, First motor + to D1 from B1 to second motor D1 and - to B1 second motor.
> ...


Looking at your profile to see if you have "garaged" this vehicle, I note that you joined this forum *exactly* one year ago today.
Can you describe or point to a description.
Regarding rotation direction, you need to reverse field relative to armature. If it runs correctly now don't change it.
Gerhard


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## major (Apr 4, 2008)

glaurung said:


> Hi,
> I have now been "driving in" my dual motor on parallel and would like to try series.I could not find info about connections but i figured it would be like this.
> On parallel D2 goes to A2, +to D1 -to B1 and same to other motor.
> Series would be D2 to A2 on both, First motor + to D1 from B1 to second motor D1 and - to B1 second motor.
> So basically like connecting batteries.


Hi Harri,

This is not the usual series motor terminal labels (A1,A2,S1,S2). Can you post a connection diagram from the nameplate or picture or something?



> If turning wrong way then alternate + and - cables and would turn right way.


No, polarity won't reverse a wound field motor. You would need to reverse the field connections.

major


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## glaurung (Nov 11, 2009)

Major, this is what official drawing has.
Harri


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## glaurung (Nov 11, 2009)

Gerhard, i should propably toast to my anniversary among you great people!
Well, it´s my day off so it has allready been done.It´s 3 a clock at night here.
I am now driving parallel and try to find series connection, all you said just missed me by a mile. I have learned a lot of batteries and some basics in a year,but most other things could be hebru and i would not notice.
Harri


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## GerhardRP (Nov 17, 2009)

glaurung said:


> Major, this is what official drawing has.
> Harri


 So, you have a dual Kostov 11...Should 
be hot. Tell us about the vehicle, batteries and controller, You should have a build thread and a garage entry.
Gerhard


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## major (Apr 4, 2008)

glaurung said:


> Major, this is what official drawing has.
> Harri


Kool  That's a hunk o' motor there 



glaurung said:


> Series would be D2 to A2 on both, First motor + to D1 from B1 to second motor D1 and - to B1 second motor.


Yeah, it looks like that would put them in series. Or you could wire it per the notes on the drawing. That would be the way to go if you need reversing contactors.

If you worry about getting them rotating against each other, try them one at a time with a 12V battery and then together with a 12V battery. That way you don't blow anything up, like your controller.

major


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## glaurung (Nov 11, 2009)

Thanks Major, lets see what happens when amps start rising.
I have been driving on nominal motor settings so far, 200v 500amp.
Gerhard, i have a build thread: Range ever build thread. I did garage it but cant remember the title, it is there somewhere.
Harri


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## MalcolmB (Jun 10, 2008)

Hi Glaurung

I'm curious about how well your motors share current in parallel. Just wondering if you've been monitoring amps independently and, if so, whether you've noticed any imbalance between the motors?

The reason I ask is that CroDriver said he had problems with one of his paralleled motors hogging the current, which led to that motor burning up. Of course, he was also pushing them a lot closer to their limit.


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## glaurung (Nov 11, 2009)

I dont have equipment to monitor that. And since i am still on test driving mode motors dont really too many amps. I will now douple the amps and change to series, just to get a feel of that. 
If i need max power on parallel i have to make some modifications to be sure that amps are equal so my Kostov doesn´t share Crodrivers fate.
I will post update on my build thread when i have tested new conficurations.
Harri


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## CroDriver (Jan 8, 2009)

Harri, I'm afraid that you don't have enough voltage to wire them in series, unless you have a really high voltage pack. 

I sent my motors back to Kostov to rewind them to 150V each so I can run them up to the RPM limit with my 330V pack. This is of course important for my racing applications since I want to get as much power as possible trough the whole RPM range. 

It might work for you without any modifications. Try it and you'll feel the difference


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## algea07 (Oct 1, 2010)

okay so i'm a noob at this but doesn't running 2 motors in series at 330v mean the first motor has 330v running through it, which is far more then what it's designed for.

i know people have done this. So am i wrong about how the voltage runs though the motor, or is it okay to do this to a motor for a short period of time, or if you make sure the rpm stays at a safe level?


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## glaurung (Nov 11, 2009)

Kostov dual11" motor is basically two motors together. Single motor is rated for 200v and 250 amp. So dual motor is therefore 400volts and 250 amps OR 200volts and 500amps, debending on how it is wired.Those are nominal amps that can be increased for a short time, allowing higher power if needed occasionally.
Think it as AA batteries, two side by side is 1.5v and two in a row is 3.0v.
Same power but in different voltage.
I have been driving in parallel now and with 200volts 1000amps limited to 160kw works fine.
Regards, Harri


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