56
Technical Data
CG Drives & Automation 01-6142-01r0
8.3
Operation at higher
temperatures
Most Emotron AC drives are made for operation at
maximum of 40°C (104 °F) ambient temperature. However,
it is possible to use the AC drive at higher temperatures with
reduced output rating.
Possible derating
Derating of output current is possible with
-1% / degree Celsius to max +15 °C (= max temp 55 °C) or
-0.55%/ degree Fahrenheit to max +27 °F
(= max temp. 131 °F).
Example
In this example we have a motor with the following data that
we want to run at the ambient temperature of
45 °C (113 °F):
Voltage
400 V
Current
72 A
Power
37 kW (50 hp)
Select AC drive
The ambient temperature is 5 °C (9 °F) higher than the
maximum ambient temperature. The following calculation
is made to select the correct AC drive model.
Derating is possible with loss in performance of
1%/°C (0.55%/ degree F).
Derating will be: 5 x 1% = 5%
Calculation for model 48-074
74 A - (5% x 74) = 70.3 A; this is not enough.
Calculation for model 48-090
90 A - (5% x 90) = 85.5 A
In this example we select the 48-090.
8.4
Operation at higher
switching frequency
Table 26 shows the switching frequency for the different AC
drive models. With the possibility of running at higher
switching frequency you can reduce the noise level from the
motor. The switching frequency is set in menu [22A],
Motor sound, see software instruction. At switching
frequencies >3 kHz derating might be needed.
Table 26
Switching frequency
Models
Standard
Switching
frequency
Range
FLD##-003 to FLD##-250
3 kHz
1.5–6 kHz
