OVERHEAT PROTECTION (AUTO-
MATIC THERMAL-CUTOUT: AHO)
When the temperature of the heat sink inside the
driver reaches approximately 176°F (80°C), the
motor output current is automatically shut off, the
alarm indicator on the front panel lights up, and the
"OVERHEAT ALARM" output signal (Pin '35) is
turned "ON" at connector CN1.
In applications where the sudden removal of motor
current could pose a safety problem (e.g. motor is
moving a weight against the force of gravity or a
spring), the AHO switch can be turned to the
"OFF" position to disable the function. If the tem-
perature of the internal heat sink reaches 176°F
(80°C) while the AHO function switch is "OFF",
the alarm indicator on the front panel will still light
up and the "OVER-HEAT ALARM" output signal
(Pin *35) will still be turned "ON" at connector
CN1 even though the A l -10 function has been
disabled. Current to the motor will not be shut off,
however.
If an overheat alarm occurs, review the application
requirements to make sure that they are within the
specifications of the
UI215GA
(Drive duty cycle,
ambient temperature, etc.), or apply forced air
cooling to the driver.
INTELLIGENT DRIVER
U1215GA
POWER •
READY •
TIMING •
ALARM •
RUN
STOP
A.C.D
A.H.0
FULL.
5 minutes
or less
Motor
running
MAX
MIN
E l l
ON
ON
HALF
Alarm
indicator
- * A H O function
override switch
Motor
stopped
with 50% current
cutback
T1 I _ T 2
The maximum recommended duty cycle (running
time vs. stopped time) for the motor and driver is
r4°
1 0
minutes or less
50% running, up to a maximum 10 minute cycle,
(i.e. up to 50% running would be up to 5 minutes
T
1
of "ON" time).
D
u
t
y
cycle = Ti + T2 x 100% < 50%
The Auto Thermal Cutoff (AHO) function is self
resetting. Once the driver has cooled sufficiently,
the motor may restart abruptly if the input signal
source is still active.
Precautions should
be taken
to ensure that the system is reset to protect
persons and property against unexpected mo-
tor activity.
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