1 Device series DC1-S…
1.8 Output reduction (derating)
22
DC1-S…20…, DC1-S…OE1 Variable Frequency Drives
05/21 MN040058EN
www.eaton.com
Examples showing how to apply derating factors
0.75 kW motor (230 V, 5.1 A), installation altitude of 2,000 m above sea level,
ambient temperature of 45 °C, wall-mounted in mechanical room, required
carrier frequency of 16 kHz (reduced operating noise).
a)
Selected variable frequency drive: DC1-S27D0FN-A6SCE1, rated operational
current of 7 A, carrier frequency of 8 kHz (default setting).
Required derating factors:
•
For the 16 kHz switching frequency:
35 %
•
For the 2,000 m installation altitude:
10 %
(1 % per 100 m above
1,000 m, 2,000 m - 1,000 m = 1,000 m, 1,000 m/100 m = 10)
•
For the 45 °C ambient temperature:
12.5 %
(2.5 % per kelvin,
45 °C - 40 °C = 5 K, IP66 degree of protection)
7 A - 35 % - 10 % - 12.5 % = (7 x 0.65 x 0.9 x 0.875) A =
3.58 A
The DC1-S variable frequency drive’s permissible continuous rated
operational current of 3.58 A is lower than the motor’s required rated
operational current (5 A).
b)
Selected variable frequency drive: DC1-S2011FB-A6SCE1, rated operational
current of 11 A.
Required derating factors:
•
For the 16 kHz switching frequency:
35 %
•
For the 2,000 m installation altitude:
10 %
(1 % per 100 m above
1,000 m, 2,000 m - 1,000 m = 1,000 m, 1,000 m/100 m = 10)
•
For the 45 °C ambient temperature:
12.5 %
(2.5 % per kelvin, 45 °C - 40 °C = 5 K, IP66 degree of protection).
11 A - 35 % - 10 % - 12.5 % = (14 x 0.65 x 0.9 x 0.875) A = approx.
5.63 A
￫
The DC1-S2011FB-A6SCE1 variable frequency drive meets the necessary
operating conditions.
￫
By using the default switching frequency instead (default
setting: 8 kHz), the motor can be operated continuously at an
altitude of 2,000 m (7 A - 10 % - 12.5 % = 5.5 A).
￫
Use a variable frequency drive belonging to a higher output
class and repeat the calculations in order to ensure that a
sufficiently high output current will be available continuously for
the required carrier frequency of 16 kHz.
Summary of Contents for DC1-S1011NB-A20CE1 1
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