Kongsberg Simrad ST90, Reference Manual

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provide 000 individual transmit- and receiver channels. The Transceiver Unit also holds an
Ethernet switch and a large capacitor bank. An internal power supply is provided to supply
the required DC voltages to the Transceiver Unit.
Note
To extend the lifetime of the Transceiver Unit, you must keep the sonar room dry and clean,
and with sufficient ventilation.
The Transceiver Unit is fitted with a commercial heat exchanger. The purpose of the heat
exchanger is to provide a stable, clean and temperature controlled environment for the
electronic circuitry inside the Transceiver Unit. The heat exchanger also inhibits dust and
dirt particles from entering the transceiver. The heat exchanger is powered from 230 VAC
using a separate outlet.
Related topics
Simrad ST90, page 17
System units, page 23
Hull Unit
The hull unit is used to lower the transducer down below the ship’s hull when the ST90
system shall be used. When the ST90 system is turned off, the transducer is hoisted for
protection.
Caution
When the transducer is lowered, the depth of water under the vessel must be monitored
closely.
If the transducer hits larger objects or bottom, the transducer shaft may be bent, or - in
worst case - it can be broken off. A broken transducer shaft will cause water leakage
through the top of the shaft. If you suspect that the transducer shaft is seriously damaged
with holes, do not retract the transducer to its upper position.
To prevent serious damage to the vessel or the vessel stability, you must have a water
pump and a warning system in the sonar room.
If you forget to hoist the transducer before the ST90 system is turned off, the transducer
is hoisted automatically before the power is disconnected. The transducer is also hoisted
automatically if a serious malfunction occurs to the communication between the bridge
and the hull unit.
In the event of improper operation, the powerful electric motor on the hull unit may cause
serious damage to the equipment and/or injury to personnel. Therefore, before you start
Simrad ST90