# [EVDL] Overvoltage on DC motors



## EVDL List (Jul 27, 2007)

> Bob Bath wrote:
> > I'm operating an 8" ADC at 144, and it's rated to
> >96 or so. I've driven 10,000 carefree miles, and the
> >brushes show no sign of wear. I've been told to
> ...


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## EVDL List (Jul 27, 2007)

> S Collins wrote:
> > Bob Bath wrote:
> > > I'm operating an 8" ADC at 144, and it's rated to
> > >96 or so. I've driven 10,000 carefree miles, and the
> ...


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## EVDL List (Jul 27, 2007)

Hi Scott,

A lot of folks run higher voltage to the DC motor than
what is listed on the nameplate (rating). I am sure
you will get other responses. I don't have time now,
but just thought I'd give you a quick note.

It is hard for a beginner to tell which ratings to
heed.

Regards,

Jeff M




> --- S Collins <[email protected]> wrote:
> 
> > Bob Bath wrote:
> > > I'm operating an 8" ADC at 144, and it's rated
> ...


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## EVDL List (Jul 27, 2007)

Hello Scott,

This depends on what type of controller you are running. My motor is rated 
for 165 volts at 175 amps at 5000 rpm. A Zilla controller controls a 180 
volt battery pack which may be charge up to 204 volts when its apply to this 
controller.

Backing out of the garage at about 5 to 10 mph in a overall gear ratio of 
22.2:1, the motor ampere is about 80 amps at 40 motor volts, while the 
battery ampere is about 20 amps at 192 battery volts.

Most of my driving is at 25 mph city driving, so when I am at that speed, 
the motor rpm is kept at about 5000 rpm at a overall ratio of the about 
13.9:1, the motor ampere is 110 amps at 100 motor volts, while the battery 
amps is at 60 amperes at a battery volts of 175 volts.

So with my 165 volt motor, my motor voltage ranges from 40 to 100 volts with 
a 180 volt battery pack. I could have a 275 volt battery pack on this 
controller and motor voltage will be in the same range with this type of 
controller.

Roland




----- Original Message ----- 
From: "S Collins" <[email protected]>
To: <[email protected]>
Sent: Friday, November 23, 2007 2:21 PM
Subject: [EVDL] Overvoltage on DC motors




> > Bob Bath wrote:
> > > I'm operating an 8" ADC at 144, and it's rated to
> > >96 or so. I've driven 10,000 carefree miles, and the
> > >brushes show no sign of wear. I've been told to
> ...


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## EVDL List (Jul 27, 2007)

Thanks, Roland and others for replying.

Roland, so what you seem to be saying is that the DC
motor is NOT overdriven in voltage - that people rely
on the controller to limit the voltage.

So, it sounds like you should not allow the controller
to apply a voltage beyond it's rating - does that
capture it?

Scott



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## EVDL List (Jul 27, 2007)

Hello Scott,

You can program the controller, for maximum motor voltage and maximum motor 
ampere which will limit the amount of accelerator control you give it. If 
the battery pack voltage is less than the rating of the controller, you set 
the battery voltage at any limit, because it cannot go beyond the controller 
voltage rating.

I find it depends on motor sizes also. When I bench test the Warp 9 which 
was driving nothing, apply 12 volts to it, the maximum rpm it turn was about 
1500 to 2000 rpm. I did not have a rpm indicator on that one.

My large GE 11 also went to about 1500 rpm on 12 volts at no load. Put a 
100 amp alternator load on the pilot shaft and it would stay at 375 rpm at 
12 volt. Apply 24 volt to it went to about 800 rpm with the load.

Applying full 165 volts at no load, it climb to 6000 rpm and may have gone 
beyond that limit, if I did not apply any load to it.

My pilot shaft of this motor runs a accessory load which is a 
alternator-inverter and vacuum pump which can keep the motor running at idle 
with the transmission in neutral.

I normally do not have to idle this type of transmission, just let it go to 
0 rpm just like a manual transmission does.

Roland


----- Original Message ----- 
From: "S Collins" <[email protected]>
To: <[email protected]>
Sent: Friday, November 23, 2007 5:08 PM
Subject: Re: [EVDL] Overvoltage on DC motors


> Thanks, Roland and others for replying.
>
> Roland, so what you seem to be saying is that the DC
> motor is NOT overdriven in voltage - that people rely
> on the controller to limit the voltage.
>
> So, it sounds like you should not allow the controller
> to apply a voltage beyond it's rating - does that
> capture it?
>
> Scott
>
>
>
> 
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> Never miss a thing. Make Yahoo your home page.
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>
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