User Manual

Cabinet description
Nortel Networks Confidential
1–6
PE/DCL/DD/0063
411–9001–063
Standard 12.07/EN September 2000
GSM/BSS V12
On each cooling unit there is also a controller display (red 7–segment display) that
indicates the internal air temperature. This controller display has two LEDs :
COOL/DELAY (red): lit when the internal air temperature reaches 40°C
(104°F).
HEAT (red): lit when the heater is on.
Technical characteristics
The ventilated air flow rate is 400 m
3
/hour (14.125 cubic feet/hour).
The maximum temperature of output air is +70°C (158°F).
With DACS
Figure 1–4 shows the S8000 Outdoor with an DACS climatic system.
The operating principle is the following:
The air damper opens to admit external air (incoming air being filtered) and
controls the inner cabinet environment by mixing appropriate amounts of outside
and recirculated air.
The twin blowers drive air down the rear duct and into the equipment enclosure
via slots at the rear. Returned air to the cooling system is routed through two sets
of holes in the base, with excess air being rejected from vents either located on
either side of the system (see Figure 1–5).
The internal temperature control is achieved by a high quality thermistor having an
accuracy of ±0.2°C (32,36_F) between 0°C (32_F) and 70°C (158_F).This device
is located in the left hand exit duct above a hole on the duct side ; this hole ensures
that the thermistor is constantly in a moving air stream, regardless of damper
position. Cooling system operational mode is solely dictated by the information
provided by the thermistor.
There are four operational modes:
Low temperature –40°C (–40°F) <Tcab <15°C (59°F)
The heater is energised, the damper closed to the outside and air is recirculated
via the holes in the base of the cooling system.
Medium temperature 15°C (59°C) <Tcab <40°C (104°F)
The heater is switch off, the damper remains closed and further heating of the
equipment enclosure is achieved solely by the internal equipment loading.