Danfoss VLT AQUA Drive FC 202 Design Manual page 86

How to Install
D-frame Cooling Fans
All frequency converters in this size range are equipped
with cooling fans to provide airflow along the heatsink.
Units in IP21 (NEMA 1) and IP54 (NEMA 12) enclosures
have a fan mounted in the enclosure door to provide more
airflow to the unit. IP20 enclosures have a fan mounted to
the top of the unit for more cooling. There is a small 24 V
DC mixing fan mounted under the input plate. This fan
operates anytime the frequency converter is powered on.
DC voltage from the power card powers the fans. The
mixing fan is powered by 24 V DC from the main switch
5 5
mode power supply. The heatsink fan and the door/top
fan are powered by 48 V DC from a dedicated switch
mode power supply on the power card. Each fan has
tachometer feedback to the control card to confirm that
the fan is operating correctly. On/off and speed control of
the fans is provided to reduce overall acoustical noise and
extend the life of the fans.
The following conditions activate fans on the D-frame:
•
Output current greater than 60% of nominal
•
IGBT over temperature
•
IGBT low temperature
•
Control card over temperature
•
DC hold active
•
DC brake active
•
Dynamic brake circuit active
•
During pre-magnetization of the motor
•
AMA in progress
In addition to these conditions, the fans are always started
shortly after mains input power is applied to the frequency
converter. Once fans are started, they run for a minimum
of one minute.
The following conditions activate fans on the E- and F-
frames:
1. AMA
2. DC Hold
3. Pre-Mag
4. DC Brake
5. 60% of nominal current is exceeded
6. Specific heatsink temperature exceeded (power
size dependent)
7. Specific power card ambient temperature
exceeded (power-size dependent)
8. Specific control card ambient temperature
exceeded
84
Design Guide
External Ducts
If more duct work is added externally to the Rittal cabinet
the pressure drop in the ducting must be calculated. Use
the derating charts to derate the frequency converter
according to the pressure drop.
Illustration 5.24 D-frame Derating vs. Pressure Change.
Frequency Converter Airflow: 450 cfm (765 m
(%)
Illustration 5.25 E-frame Derating vs. Pressure Change (Small
Fan), P250T5 and P355T7-P400T7. Frequency Converter
Airflow: 650 cfm (1,105 m
(%)
Illustration 5.26 E-frame Derating vs. Pressure Change (Large
Fan), P315T5-P400T5 and P500T7-P560T7. Frequency
Converter Airflow: 850 cfm (1,445 m
Danfoss A/S © Rev. 06/2014 All rights reserved.
(%)
90
80
70
60
50
40
30
20
10
0
0 0.5 4.9 13 27.3
Pressure Increase
90
80
70
60
50
40
30
20
10
0
0 0 0.1 3.6 9.8 21.5 43.4
Pressure Change
3 /h)
90
80
70
60
50
40
30
20
10
0
0 0.2 0.6 2.2 5.8 11.4 18.1 30.8
Pressure Change
45.9 66 89.3 115.7 147
(Pa)
3 /h)
76 147.1 237.5 278.9
(Pa)
69.5 152.8 210.8
(Pa)
3
/h)
MG20Z202