Selection Of Transformer - Danfoss VLT Active Front End AFE 302 Operating Instructions Manual

Crane System Design
(%)
90
80
70
60
50
3 3
40
30
20
10
0
0 0.5
Illustration 3.1 D frame derating vs. pressure change
frequency converter air flow: 450 cfm (765 m
(%)
90
80
70
60
50
40
30
20
10
0
0 0
Illustration 3.2 E frame derating vs. pressure change (small
fan), P355T7-P400T7
frequency converter air flow: 650 cfm (1105 m
(%)
90
80
70
60
50
40
30
20
10
0
0 0.2
Illustration 3.3 E frame derating vs. pressure change (large
fan), P500T7-P560T7
frequency converter air flow: 850 cfm (1445m
10
4.9 13 27.3 45.9 66 89.3
Pressure Increase
3
0.1 3.6 9.8 21.5 43.4 76 147.1
Pressure Change
0.6 2.2 5.8 11.4 18.1 30.8 69.5
Pressure Change
Danfoss A/S © Rev. 05/2014 All rights reserved.
Operating Instructions
(%)
90
80
70
60
50
40
30
20
10
0
115.7 147
0
(Pa)
Illustration 3.4 F1, F2, F3, F4 frame derating vs. pressure
/h)
change
frequency converter air flow: 580 cfm (985 m

3.1.9 Selection of Transformer

•
•
237.5 278.9 NOTICE
(Pa)
Danfoss reviews/evaluates the LCL filter design for each
application especially when the new transformer is used.
3 /h)
152.8 210.8
(Pa)
3 /h)
25 50 75 100 125 150
Pressure Change
The output of the HT-transformer must be
specified for 630 V.
It is recommended to use 2 separate transformers
for 630 V and the 400 V and these transformers
should be physically separated. The 400 V
transformer must be close to or in the E-house to
have a short ground cable.
175 200 225
3
/h)
MG33X402