323,9
[12,8]
0
[0]
0 [0
]
0 [0
]
38
0,
7
[1
5]
16
9,
7
[6
,6
]
25
8,
7
[1
0,
2]
34
8,
7
[1
3,
7]
13
0B
B7
24
.1
0
Illustration 4.15 Terminal Location of Frame E9
NOTE
Note that the power cables are heavy and difficult to
bend. Consider the optimum position of the unit for
ensuring easy installation of the cables.
Each terminal allows use of up to 4 cables with cable lugs
or use of standard box lug. Earth is connected to relevant
termination point in the unit.
4.3.5 Cooling and Airflow
Cooling
Cooling can be obtained in different ways, by using the
cooling ducts in the bottom and the top of the unit, by
taking air in the back of the unit or by combining the
cooling possibilities.
Back cooling
The design of the active filter is built on a backchannel
cooling system where 85% of all heat is ducted via an IP54
segregated backchannel. This reduces the needed airflow
inside the enclosure and ensures less moist and dust
ventilation across vital components.
The backchannel air is normally ventilated via the plint
inlet and ducted out the top of the enclosure. The design
of the backchannel does, however, also allow air to be
taken from outside the control room and dusted back out
again. This is supported to ease stress on the control room
air conditioner and so conserve energy. To support back
wall inlet, the unit air inlet has to be blocked via an
optional cover and the air outlet ducted via an optional
top duct.
NOTE
A door fan(s) is required on the enclosure to remove the
heat losses not contained in the backchannel of the unit
and any additional losses generated from other
components installed inside the enclosure. The total
required air flow must be calculated so that the
appropriate fans can be selected. Some enclosure
manufacturers offer software for performing the
calculations (i.e. Rittal Therm software).
Airflow
The necessary airflow over the heat sink must be secured.
The flow rate is shown below.
Enclosure
IP21 / IP54
IP21/54
Frame size
D13/D9
E9, E7
Door fan
340m
3
/h (200 cfm)
340m
3
/h (200 cfm)
Heatsink
765m
3
/h (450 cfm)
1230m
3
/h (725 cfm)
Table 4.1 Heatsink Air Flow
NOTE
For the active filter, the fan runs for the following reasons:
1.
Active filter running
2.
Specific heatsink temperature exceeded (power
size dependent)
3.
Specific Power Card ambient temperature
exceeded (power size dependent)
4.
Specific Control Card ambient temperature
exceeded
Once the fan is started it will run for minimum 10 minutes.
External ducts
If additional duct work is added externally to the Rittal
cabinet the pressure drop in the ducting must be
calculated. Use the charts below to derate the unit
according to the pressure drop.
90
80
70
60
50
40
30
20
10
0
0
0.5
4.9
13
27.3
45.9
66
89.3 115.7 147
(%)
(Pa)
Pressure Increase
Filt
er D
er
ating
130BB932.10
Illustration 4.16 D frame Derating vs. Pressure Change
Air flow: 450 cfm (765 m
3
/h)
How to Install
VLT Active Filter AAF 00x
MG.90.V2.02 - VLT® is a registered Danfoss trademark
19
4
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