Roland wrote

> > > Motors are inductive loads, where the ampere will rise with increase

> > > voltage

> > >

> > > Unlike resistance loads as a heater, where if you have a 240 v heater

> > > Element at 8 amps, it will become 4 amps at 120 v.

> > >

> > > A motor that it windings are rated for 240 v may use 10 amps where A

Motor

> > > Has its windings rated for 120 V may use 20 amps for the same hp. But

> > > using

> > > Different voltages on the same windings rated for some other voltage

The

> > > Ampere may increase as follows:

> > >

> > > Here is the results of a 180 VDC motor test I did using different

Voltages

> > > At no load:

> > >

> > > Battery Pack Actual Volts Amperes Rpm

> > >

> > > 12 12.6 5 634

> > > 18 18.9 6 1013

> > > 24 25.4 6.2 1390

> > > 30 31.8 6.4 1773

> > > 36 37.8 6.6 2143

> > > 42 44.5 6.8 2521

> > > 48 51.2 7.0 2985

> > > 54 57.5 7.5 3270

> > > 60 63.7 8 3715

> > >

> > > There is a maximum voltage and ampere rating you can go over on a

Motor.

> > > This is call the Service Factor (SF). If 115V motor has a rated SF of

115%

> > > And the motor has a ampere rating of 200 ampere for continuous running

> > > then

> > >

> > > 200A x 1.15 = 230 amps. The 115V motor can run on 115V x 1.15 = 132.25

V.

> > >

> > > On the label for the motor, there should be a Service Factor which may

Say

> > > SF 1.25 for a DC motor. I don't why the ADC and Warp motors do not

Have

> > > Motor label that list the specifications of the motor.

> > >

> > > My General Electric motor does. It list the DC motor as 165 volts at

175

> > > Amps at 32 HP with a SF of 1.25 meaning the over voltage can be about

208

> > > Volts and the over ampere can be 218 amperes continuous.

> > >

> > > Roland

Therefore what I need to know is .

If I chooses to go with 72 volts on my 30volt rated motor hoping to use less

Than half the amps to do the same job .. Will that really be what I get??

According to the above maybe not..

However..

Am I missing that some controllers actually decrease and control the

Actually amps delivered to the motor?

As I was told earlier here . They don't change the amount of amps .. Just

That amount of time that the amps are applied to the motor.. Or are some

Controllers different in that since.. ..

So if I understand what I am herring.. Then also if the actually amps are

Not changed .. If I open my controller up full to achive max speed the

Amount of amps will not be decreased and my poor motor will die If the amps

Raise and double when I raise the volts that I am considering to make my car

With 72 instead do 30volts..

Tanks Mitchell