User's Manual

6-4 Aviat Networks
Chapter 6. Installing the INU and INUe
Node Card Maximums
The following guidelines should be used to determine maximum INU card/power
loadings for various node (INUe) configurations. Maximums are primarily determined
by operating temperature limits imposed on the DC converter modules in the NCC (and
NPC).
These card maximums apply up to the maximum ambient of 45
o
C (112
o
F). Higher
loadings may be permitted for lower ambients. Note that for cabinet-mounted INUs
the ambient temperature is the temperature within the cabinet.
INUe card loading maximums are:
• Five RAC 60 cards plus any three DACs
• Four RAC 6X cards plus any three DACs.
Note that:
• RACs should always be installed on the FAN side of the INU for best cooling
efficiency.
•A 2RU FAN
1
must always be used in an INUe with a high card loading. It provides
superior cooling compared to two 1RU FAN modules.
• Elevated ambient temperatures should be avoided. The 45
o
C (112
o
F) ambient
maximum must not be exceeded. Over-temperature operation is a primary factor
affecting long term component reliability.
PCC +24 Vdc Operation
The PCC is for use with standard +24 Vdc (-ve grounded) battery-backed power supply
systems. One PCC supports a maximum three IRU 600 RFUs, plus any combination of
RACs and DACs.
• The PCC +ve and -ve input terminals are isolated from chassis (ground). The -ve
input is grounded by the -ve grounded power supply connection.
• The PCC 20A fuse is fitted in the +ve input. It is a PCB mount type and is not field
replaceable.
• Reverse polarity protection is provided. The PCC will automatically recover from a
reverse polarity connection - the fuse will not blow. Over temperature thermal
protection is included.
• The PCC load maximum is 200 Watts. Use the power consumption data in the
preceding section to determine the maximum number of cards and RFUs that can be
supported.
• The PCC conversion efficiency is nominally 10%. To determine the power consumed
by the PCC, use a figure of 10% of the power consumed by the INU/INUe cards and
IRU 600 RFUs.
1+1 FD Standard Power (2xRFU) 104W N/A 104W
1+1 FD High Power (2xRFU) 104W 76W 180W
Configuration Power Sourced
from INU
Power Sourced
from External DC
Connector
Total DC
Power
1
A 2RU FAN is standard with an INUe, but an INUe can be fitted with two 1RU FANs.