Cart Stopped On Hill, Had to Rest with Tow Switch

[HiTechRedNeck]

kgsc is correct 3 phase ac is reason for lower heat..
Ac Motor theory more than i want to try to go into here..
Sufficient to say ac motors have taken over in industrial applications for a reason.
Cart is computer controlled.... technically a PLC (Programmable logic controller).
Not much that mortal man can do to change the basic operation. It Works or it dose not.
Some settings (speed,regen brake aggressiveness.error codes) and a few others are accessible with EZ GO scan tool (Unavailable-dealer only).

was hint to not push brake while powering up or changing from fwd to rev helpful ?

with EZ GO scan tool

[HiTechRedNeck]

here is a little help on ac motor operation (an why it runs cooler)
in a dc motor the speed of the motor is proportional to the voltage applied to it.
Higher voltage higher speed.
Current flow is proportional to voltage and resistance.
although resistance does change with speed and load in dc motor- for this discussion we will consider resistance as fixed.
so when you go faster with dc cart you have a much greater current flow throgh the motor. more current more heat.

in an ac motor the motor turns when the rotor(center part-Armature on dc motor)
trys to align with the stator(Wire windings attached to case).
AC motor speed is determined by the frequency of the ac power input and is not affected by current or voltage.
so a motor turning fast uses the same current as a motor turning slow.(not exactly power use does go up but not as much as with a dc motor)
since speed is not dependent on voltage- PLC controller can lower voltage and power-heat and still maintain rotational speed .
also allows regen brake function powerful enough to ELIMINATE mechanical brake
EXCEPT for parking/emergency brake.

please let me know if this is helpful--- will try to answer any questions

[radioman]

Originally Posted by HiTechRedNeck

here is a little help on ac motor operation (an why it runs cooler)
in a dc motor the speed of the motor is proportional to the voltage applied to it.
Higher voltage higher speed.
Current flow is proportional to voltage and resistance.
although resistance does change with speed and load in dc motor- for this discussion we will consider resistance as fixed.
so when you go faster with dc cart you have a much greater current flow throgh the motor. more current more heat.

in an ac motor the motor turns when the rotor(center part-Armature on dc motor)
trys to align with the stator(Wire windings attached to case).
AC motor speed is determined by the frequency of the ac power input and is not affected by current or voltage.
so a motor turning fast uses the same current as a motor turning slow.(not exactly power use does go up but not as much as with a dc motor)
since speed is not dependent on voltage- PLC controller can lower voltage and power-heat and still maintain rotational speed .
also allows regen brake function powerful enough to ELIMINATE mechanical brake
EXCEPT for parking/emergency brake.

please let me know if this is helpful--- will try to answer any questions

How is the AC generated and what frequency is it? Is it sine wave or distorted AC? How does it generate three phase AC? Does the speed ranges vary with the number of phases or all three applied at once? It is just a mysterious cart because not much information is available here.

[HiTechRedNeck]

Google 3 phase electric motor operation -- lots of info.
ac is generated by selectively switching voltage and polarity to motor output wires.
haven't put o-scope on output. probably not true sine wave but that really is not relevant
for troubleshooting or repair.
Speed of ac motor is determined by FREQUENCY of ac applied.
controller manipulates frequency to control motor rotational speed.


http://en.wikipedia.org/wiki/Synchronous_motor