[ausev] Progress so far on 91 MR2 conversion, and a question

[Brian Lasseter]

On Mon, Feb 9, 2009 at 4:41 PM, John Flores-McLaughlin
<johnfm101 at gmail.com> wrote:
> Did you ever figure out why your motor blew?

It was overloaded.   To be more specific, to my recollection the
system pressure got too high, and the proper thing to do would have
been to shut off the motor, and then cycle it back on as the pressure
dropped.  (As the car itself does.)  But we didn't have the car's A/C
controls hooked up yet, the fans were not blowing on the evaporator or
condenser coils, the pressure sensor wasn't hooked up yet, and we were
not watching the A/C pressure.  So... the motor tried and tried to
compress the R134a further... until the magic smoke left the motor.

A proper controller to turn it on and off in regards to system
pressure would have been needed, and I didn't have that built yet.  I
now have a small transistor controller to turn on and off the
Masterflux A/C controller when the car's A/C pressure sensors sense a
problem (or when I press the A/C button on the dash to turn it off).
I would have needed a much larger version to control a high voltage DC
motor.

It was just easier and faster at the time to just buy a Masterflux A/C
unit.  That, and Revolt Custom Electric vehicles really wanted to get
their hands on one to try out.   :-)


TTFN,
Brian "Lasso" Lasseter

"No Sane man will dance."   -Cicero (106-43 B.C.)