Curtis 1243
GEN
2 Manual
44
The 1243
GEN
2 controller can protect the motor from damage due to overtemperature
by cutting back the motor speed. An estimate of the motor temperature is derived from
the resistance of the field winding. The controller measures field current, field PWM,
and battery voltage, and uses these measurements to calculate the instantaneous field
resistance. This value is filtered and compared to two setpoints: Motor Warm
Resistance and Motor Hot Resistance. If the field resistance reaches the Motor Warm
Resistance setpoint, the motor maximum speed will be limited to the programmed
Warm Speed. If the field resistance reaches the Motor Hot Resistance setpoint, the
controller will no longer drive but all braking functions will remain active. If this
motor protection feature is not desired, it can be disabled by programming the motor
resistance compensation parameter Off.
WARM SPEED
The
warm speed
parameter de
fi
nes the maximum drive speed output when the
motor
fi
eld resistance is at or above the Motor Warm Resistance setpoint. The
warm speed is adjustable from 0 to 100% of drive output.
MOT WRM x10 m
Ω
The
motor warm resistance
parameter de
fi
nes the
fi
eld resistance setpoint at
which a motor warm fault will occur and the maximum speed will be controlled
by the Warm Speed setting.
Note: The parameter value is in ten-milliohm units. If you want to program
the Motor Warm Resistance setpoint to 900 m
Ω
(0.9
Ω
), you would enter 90
for the
MOT WRM x10 m
Ω
value. The Motor Warm Resistance setpoint is adjust-
able from 100 m
Ω
(
MOT WRM x10 m
Ω
=10) up to the Motor Hot Resistance
setpoint.
MOT HOT x10 m
Ω
The
motor hot resistance
parameter de
fi
nes the
fi
eld resistance setpoint at
which a motor hot fault will occur and no drive output will be allowed. It is
adjustable from the Motor Warm Resistance setpoint up to 2500 m
Ω
(2.5
Ω
).
The value entered is in ten-milliohm units, which means the maximum Motor
Hot Resistance value is one-tenth of 2500 (i.e.,
MOT HOT x10 m
Ω
=250).
MOT
Ω
COMP
The
motor resistance compensation
parameter is used (programmed On) to
enable the motor overtemperature protection feature.
Motor Protection Parameters
3 — PROGRAMMABLE PARAMETERS:
Motor Protection Parameters