3.2.4 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 and out the back of the unit or by combining
the cooling possibilities.
Duct cooling
A dedicated option has been developed to optimize instal-
lation of drive types in Rittal TS8 Units utilizing the fan of
the adjustable frequency drive for forced air cooling of the
backchannel. Please consult GE for more details.
The air out the top of the Unit could but ducted outside a
facility so the heat loses from the backchannel are not
dissipated within the control room reducing air-
conditioning requirements of the facility.
Back cooling
The backchannel air can also be ventilated in and out the
back of a Rittal TS8 Unit. This offers a solution where the
backchannel could take air from outside the facility and
return the heat losses outside the facility thus reducing air-
conditioning requirements.
Airflow
The necessary airflow over the heatsink must be ensured.
The flow rate is shown below.
Unit Size
protection
Door fan(s) / Top fan
airflow
Heatsink fan(s)
IP21 / NEMA 1
700 m
3
/h (412 cfm)*
985 m
3
/h (580 cfm)*
IP54 / NEMA 12
525 m
3
/h (309 cfm)*
985 m
3
/h (580 cfm)*
Table 3.1 Heatsink Air Flow
* Airflow per fan. Unit Sizes 5X contain multiple fans.
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 adjustable
frequency drive according to the pressure drop.
90
80
70
60
50
40
30
20
10
0
(%)
Dr
iv
e D
er
ating
0
25
50
75
100
125
150
175
225
130BB190.10
200
Pressure Change
Figure 3.16 Unit Size 61, 62, 63 and 64 Derating vs. Pressure
Change
Drive air flow: 985 m
3
/h (580 cfm)
3.2.5 Connector/Conduit Entry - IP21
(NEMA 1) and IP54 (NEMA12)
Cables are connected through the connector plate from
the bottom. Remove the plate and plan where to place the
entry for the connectors or conduits. Prepare holes in the
marked area on the drawing.
NOTE!
The connector plate must be fitted to the adjustable
frequency drive to ensure the specified protection degree,
as well as ensuring proper cooling of the unit. If the
connector plate is not mounted, the adjustable frequency
drive may trip on Alarm 69, Pwr. Card Temp
130BB073.10
Figure 3.17 Example of proper installation of the connector
plate.
Mechanical Installation
VLT AQUA 12-Pulse High Power Instruction Manual
3-14
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