CG Emotron VFX Series, Instruction Manual

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CG Drives & Automation 01-5326-01r5 Technical Data 243
14.3 Operation at higher
temperatures
Most Emotron AC drives are made for operation at
maximum of 40 °C (104 °F) ambient temperature.
Frame sizes C69/D69/C2(69)/D2(69) are rated at 45 °C
(113 °F). 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).
* max +10 °C for sizes C69/D69/C2(69)/D2(69).
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 VFX48-074
74 A - (5% x 74) = 70.3 A; this is not enough.
Calculation for model VFX48-090
90 A - (5% x 90) = 85.5 A
In this example we select the VFX48-090.