User Manual

Cabinet description
Nortel Networks Confidential
1–2
PE/DCL/DD/0063
411–9001–063
Standard 12.07/EN September 2000
GSM/BSS V12
With ACUs
Figure 1–1 shows the S8000 Outdoor with an ACU climatic system.
The top and main compartments communicate through main compartment air inlets
and main compartment outlets (see Figure 1–2). The top compartment has
openings on the cabinet front panel that allow air to enter the cooling units and
openings on the rear of the cabinet that allow the cooling units to fan air out of the
cabinet.
Each ACU includes a compressor (ac–powered), an evaporator, condenser coils and
refrigerant lines, external and internal air blowers, 1000W heater (resistance plate
heater), digital controller, internal and ambient air temperature sensors, air filters,
EMI filters, ac/dc rectifier/alarm board and circuit breakers.
The internal temperature sensors are used to regulate the temperature inside the
cabinet. They are located on the climatic units, at the opening enabling air to pass
from the main compartment to the top compartment. The ambient air temperature
sensors enable the PCU to cut its dc power supply when the thresholds are exceeded.
These sensors are located above the BCF or CBCF compartment or below the
rectifiers.
The external air blower is to circulate the outside air across a condenser to extract
heat from the refrigerant and expel heat to the outside air. The internal air blower
circulates air through the BTS and over an evaporator to collect heat from the
electronics.
There are six LEDs on the front side of each cooling unit. These LEDs indicate the
alarms detected on the following type of failure (see Figure 1–3):
CTRL (orange): The controller display is alarmed.
FAN (orange): The fans for ambient air and internal equipment air are alarmed.
Each airflow path contains sensors to measure the air blower speed for an air
mover failure.
HP (orange): The pressure inside the compressor is controlled to sense a high or
low pressure for a compressor failure.
CS (green) : At cold start the LED comes on if the ACUs are well ac–powered.
dc (green) : The dc breaker is alarmed.
ac (green) : The ac breaker is alarmed.
These LEDs are lit when healthy and off on alarm.