Danfoss VLT AutomationDrive FC 360, Руководство по конструкции

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4.7 Special Conditions
Under some special conditions, where the operation of the
frequency converter is challenged, consider derating. In
some conditions, derating must be done manually.
In other conditions, the frequency converter automatically
performs a degree of derating when necessary. This is
done to ensure the performance at critical stages where
the alternative could be a trip.
4.7.1 Manual Derating
Manual derating must be considered for:
•
Air pressure–for installation at altitudes above 1
km.
•
Motor speed–at continuous operation at low RPM
in constant torque applications.
•
Ambient temperature–above 45
°
C (for some
types above 50
°
C), for details, see Table 4.15 and
Table 4.16 .
Enclosure size Power size
[kW]
Maximum output
current at 45 °C Maximum output
current at 50 °C
J1
0.37 1.2 1.2
0.55 1.7 1.7
0.75 2.2 2.2
1.1 3.0 3.0
1.5 3.7 3.0
2.2 5.3 4.1
J2
3 7.2 7.2
4 9.0 9.0
5.5 12.0 10.2
J3 7.5 15.5 13.1
J4
11 23.0 23.0
15 31.0 26.0
J5
18.5 37.0 37.0
22 42.5 40.0
J6
30 61 61
37 73 73
45 90 77
J7
55 106 106
75 147 125
Table 4.15 Derating at 380 V
Enclosure size Power size
[kW]
Maximum output
current at 45 °C Maximum output
current at 50 °C
J1
0.37 1.1 1.1
0.55 1.6 1.6
0.75 2.1 2.1
1.1 3.0 2.8
1.5 3.4 2.8
2.2 4.8 3.8
J2
3 6.3 6.3
4 8.2 8.2
5.5 11.0 9.4
J3 7.5 14.0 11.9
J4
11 21.0 21.0
15 27.0 22.6
J5
18.5 34.0 34.0
22 40.0 37.7
J6
30 52 52
37 65 65
45 77 76
J7
55 96 96
75 124 117
Table 4.16 Derating at 480 V
4.7.2 Automatic Derating
The frequency converter constantly checks for critical
levels:
•
Critical high temperature on the control card or
heatsink.
•
High motor load.
•
Low motor speed.
•
Protection signals (overvoltage/undervoltage,
overcurrent, ground fault and short circuit) are
triggered.
As a response to a critical level, the frequency converter
adjusts the switching frequency.
Specifications Design Guide
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