NoteA hull unit may be provided as an option. It allows you to lower and hoist the transducer.
CautionWhen 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.
TipSN92HPX, 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 |
Lowering depth (m) |
Transducer cables (m) |
Maximum speed (knots) |
SN92H |
1.2 |
13 |
16 |
SN92HPX |
1.2 |
13 |
14 |
SN93H |
1.6 |
13 |
14 |
SN93HPX |
1.6 |
13 |
12 |
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 mechanical construction it shuts off the bottom of the installation trunk when the SN90 system is not used.
For more information, refer to the end-user documentation provided by the manufacturer.