L-3 Communications Navigation Echosounder LAZ 5100 - Manual (Page 65)

Page 5-2
L-3 ELAC Nautik
Once the transducer has been installed, the system must be set up to take certain factors into
consideration. These are:
• Never paint the radiating surface of the transducer.
• Transducer installation depth beneath the surface.
• Transducer installation height relative to the lowest part of the ship's keel.
• Blocking depth, a setting to prevent false digital depth readings caused by resonance of
non-ELAC transducers. This setting need not be altered from ZERO if using ELAC
transducers.
• Frequency of the transducer.
• Installation position of the transducer, e.g. BOW, AFT, Pt., Stb, (if 2 transducers are
installed).
When a transducer is installed, i.e. before the ship is launched, measure the height difference
between the radiating surface of the transducer and the lowest part of the keel and the distance
between the waterline and the radiating surface of the transducer. These measurements are
needed to compensate the differences when the system is initially set up. The transducer
frequency can be found in the shipping documents.
Connect the system up in accordance with the connection diagram which can be found in chap. 6.
When cabling the system, take especial care that all signal lines are screened properly. The cable
from the transducer to the connection box must be laid in an iron tube. From the connection box to
the echo sounder there are three choices for a proper cable laying:
- the transducer cable is laid within an iron tube
- a double-screened cable is used as transducer cable, the inner screen is one-side
connected to the echosounder's ground, the outer screen is one-side connected to the
ship's ground.( see Figure 5- 1)
- the transducer cable is laid apart at least 500 mm from all other cables.
By no means a single screened cable must be laid together with any other cable.