21
It is recommended
that the drive be
used with Inverter Duty
or TENV motors.
Inverter duty and most
totally enclosed non-
ventilated (TENV) motors
can provide full rated
torque over an extended
speed range without
overheating. See Figure 5.
If external fan cooling is
provided, open ventilated
motors can also achieve
an extended speed range
at full rated torque. A box
fan or blower with a mini-
mum of 100 CFM is rec-
ommended. Mount the
fan or blower so the
motor is surrounded by
the airflow. See Figure 6.
Motors
and TENV
Inverter Duty
M
ax
im
um
Al
lo
w
ed
M
ot
or
To
rq
ue
(%
)
TEFC and Open Ventilated
Motors
Fan Cooled
100
60
70
80
50
30
40
10
0
20
90
Motor Speed (%)
40
0
20
60
80
100
FIGURE 5 – MAXIMUM ALLOWED MOTOR TORQUE VS. SPEED
Open Ventilated Motor
Fan or Blower
(100 CFM Min.)
Airflow
FIGURE 6 – OPEN VENTILATED MOTOR WITH EXTERNAL COOLING
