Kongsberg Simrad SN90 Reference Manual page 28

Simrad SN90 Reference Manual
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 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 SN90 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 manual operation, read carefully through the relevant operating procedures.
You must familiarize yourself with the correct handling methods and the relevant safety
requirements.
Tip
SN92HPX, SN93HPX: The transducer housing provided for the hull unit can be fitted
with two hydrophones. A hydrophone is a vital part of a gear monitoring system. The
hydrophone receives the acoustic communications from the gear sensors and converts
these to electrical signals.
Both hydrophones point aft.
The hydrophones are connected to a catch monitoring receiver.
The SN90 system can be provided with one of the following hull units:
Hull Unit
SN92H
SN92HPX
SN93H
SN93HPX
SN92HPX, SN93HPX: Two trawl hydrophones are added for use with a catch monitoring system.
Both hydrophones point aft.
On some vessels, additional transducer protection is required. One example is vessels
working in arctic conditions. It is important for them to prevent ice from damaging
the transducer. A gate valve is then added to the hull unit installation. By means of a
26
Lowering depth (m)
1.2
1.2
1.6
1.6
Transducer cables (m)
13
13
13
13
Maximum speed
(knots)
16
14
14
12
381294/E