Danfoss VLT FC 102 Series Design Manual page 40

Introduction to VLT® HVAC D...
Sizing examples for nominal power rating
2 2
Example 1
•
PM motor size: 1.5 kW / 2.9 A
•
Line power: 3 x 400 V
Adjustable
Frequency Drive
P1K1
P1K5
Table 2.10 Sizing Data for 1.5 and 2 hp [1.1 and 1.5 kW] Adjustable Frequency Drives
The current rating of the PM motor (2.9 A) matches the current rating of both the 1.5 hp [1.1 kW] adjustable frequency
drive (3 A @ 400 V) and the 2 hp [1.5 kW] adjustable frequency drive (4.1 A @ 400 V). However, since the power rating of
the motor is 2 hp [1.5 kW], the 2 hp [1.5 kW] adjustable frequency drive is the correct choice.
Power
Current
Table 2.11 Correctly Sized Adjustable Frequency Drive
Example 2
•
PM motor size: 7.5 hp [5.5 kW] / 12.5 A
•
Line power: 3 x 400 V
Adjustable
Frequency Drive
P4K0
P5K5
Table 2.12 Sizing Data for 5 and 7.5 hp [4.0 and 5.5 kW] Adjustable Frequency Drives
The current rating of the PM motor (12.5 A) matches the current rating of the 7.5 hp [5.5 kW] adjustable frequency drive
(13 A @ 400 V), not the current rating of the 5 hp [4.0 kW] adjustable frequency drive (10 A @ 400 V). Since the power
rating of the motor is 7.5 hp [5.5 kW], the 7.5 hp [5.5 kW] adjustable frequency drive is the correct choice.
Power
Current
Table 2.13 Correctly Sized Adjustable Frequency Drive
38
Design Guide
Typical [kW] Typical [hp] at
460 V
1.1 1.5
1.5 2.0
Motor
2 hp [1.5 kW]
2.9 A
Typical [kW] Typical [hp] at
460 V
4.0 5.0
5.5 7.5
Motor
7.5 hp [5.5 kW]
12.5 A
Danfoss A/S © Rev. 06/2014 All rights reserved.
Continuous Intermitted
[A] [A]
(3x380–440 V) (3x380–440 V)
3.0 3.3
4.1 4.5
Adjustable Frequency Drive 2 hp [1.5 kW]
2 hp [1.5 kW]
4.1 A @ 400V
Continuous Intermitted
[A] [A]
(3x380–440 V) (3x380–440 V)
10.0 11.0
13.0 14.3
Adjustable Frequency Drive 7.5 hp [5.5 kW]
7.5 hp [5.5 kW]
13 A @ 400 V
Continuous Intermitted
[A] [A]
(3x441–480 V) (3x441–480 V)
2.7 3.0
3.4 3.7
Continuous Intermitted
[A] [A]
(3x441–480 V) (3x441–480 V)
8.2 9.0
11.0 12.1
MG11BC22