Service Manual
GSM-204-323
Horizonmacro outdoor temperature control
31st Oct 01
Tech. 3–2
Technical Description: Horizon
macro
outdoor
CONTROLLED INTRODUCTION
68P02902W02-A
Power supply enclosure temperature sensors
The power supply enclosure temperature sensors are located on the control and
alarm board (see Outdoor PSU control and alarm board (CAB)) and consist
of the following:
One 70 C sensor, providing sensing for a cabinet overtemperature alarm
when the non EMC enclosure temperature exceeds the planned level. The
alarm is generated by the control and alarm board, and passed as an
external alarm to the alarm module, where it is sent on to the OMC-R via
the BSC. Operation of this sensor will also reduce the TOPSM output
voltage as described in Outdoor PSU control and alarm board (CAB).
One 78 C sensor, which initiates disconnection of the battery contactor,
the comms contactor and shutdown of the TOPSMs. This will shut down
the BTS. If a shutdown occurs, there is no prior notification to the OMC-R.
TMS temperature sensors
The two TMS temperature sensors are located within the TMS unit (see
Thermal management system (TMS) Figure 3-2), in the returned recirculation
airflow from the EMC and non EMC enclosures. They have the following
functions:
Either sensor provides sensing for the TMS overtemperature alarm when
the TMS returned recirculation air temperature exceeds 68C. The alarm
is generated by the TMS control board, processed by the control and
alarm board, and passed as an external alarm to the alarm module, where
it is sent on to the OMC-R via the BSC.
The TMS temperature sensors also provide the TMS control board with
thermal data used in controlling fan speed and heater operation.
Cabinet restart
after shutdown
The cabinet is restarted when the overtemperature condition initiating shutdown
has reset.
The CAB re-enables the TOPSMs when the 78 C temperature sensor
has reset at 60 C.
The two 85 C temperature sensors reset at 55 C. This re-establishes an
earth point for the PSM internal detectors connected to the cabinet heat
sensors, which then reactivate the PSM outputs.
The cabinet then restarts as a normal power up.