# 288V with a WarP 9"?



## jpontius (Feb 7, 2008)

Hey guys, 
I'm fairly new to the EV things, and have been doing a lot of reading/drooling. One thing I'm a little bit confused about is the voltage rating for DC motors. At the following link, a roadster has been built with a WarP 9" motor at 288V. Isn't this motor rated up to 144V? Is there not really a maximum voltage for dc motors? Basically, I don't understand how this is not bad for the motor. I do understand that at this higher voltage, a smaller current is used to produce a given amount of power, when compared to a 144V system. I understand that excessive current can lead to excessive motor temp, but I guess I don't really understand the potential risk of using a higher voltage. Enlighten me!

http://www.evalbum.com/1479


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## Hi Torque Electric (Dec 23, 2007)

Hey JP

The Warp9's have a brush advancement of 12.5 degrees and the ADC9's have a 10 degrees. Netgain's official maximum voltage is 170 volts and due to the 10 degree setting on the ADC, it might have a slightly lower max. People running higher voltages limit the motor to that voltage or they flash over as they can not commutate it. Here's a link to some pics I took of Waylands motor after a race where he was over 160 volts to the motor. As it's something that doesn't happen all the time even for the racers it's a hard animal to get data from bt IMO RPM's and current also play a role in when / if it will happen or not, anyway this is why you better limit your voltage to the motor.

http://hitorqueelectric.com/gallery/v/ouch/Woodburn+flashover/


The Zilla controller can be programed to limit voltage and is a popular high voltage / current controller, which also can set a max RPM for the motor so they don't do this:

http://hitorqueelectric.com/gallery/v/ouch/Blown+Commutators/

Hope this helps
Jim Husted
Hi-Torque Electric


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## jpontius (Feb 7, 2008)

thanks a lot. that makes sense. So what that guy is doing is probably a bad idea? 


from what i gather, the ADC FB1-4001 and WarP 9" seem to be the most powerful common motors for EVs. What are some other high-power options? (assuming sufficient battery/controller source)

Also, am I wrong in thinking that AC induction motors offer more potential power than DC? Is this why companies like Tesla Motors and Wrightspeed use the AC systems to produce 185kW systems? I just haven't seen any power ratings this high for any single DC motor systems.


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## BHall (Aug 1, 2007)

Even though the voltage to the motor is limited, I am seeing where higher voltages are advantageous http://www.evalbum.com/1001. Play with voltages here http://www.evconvert.com/tools/evcalc/ not sure how this page actually figures it in regarding limited voltage to the motor, but higher voltage gets a little more range. And I would be willing to bet it helps during acceleration too. Maybe someone with experience running high voltage will chime in.

Brian


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## Mastiff (Jan 11, 2008)

You could go with a Warp 11 motor if you wanted higher voltage:
http://www.beepscom.com/product_p/mo-00-08311.htm

They're pretty big at 11" but it says it goes up to 192 volts, that's 48 volts higher than a 144 volt system.

Or you can go with an AC system, they're usually in the 300 volt range, I've seen some AC motors at http://www.metricmind.com/index1.htm that go up to 900 volts and 150KW  that's 200 Horsepower.


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