Installing the transducer cables
When the transducer has been placed under its mounting location, the cables can be pulled through the steel conduit up to the Transceiver Unit.
Prerequisites
In order to do this task, the following prerequisites must be met.
•  All relevant work instructions, procedures and standards must be available.
•  The mounting ring has been installed.
•  The steel conduit is mounted with all installation work finalized.
•  All relevant drawings have been approved by the classification society.
•  All relevant personnel (skilled shipyard workers, ship electricians) and their tools must be available.
You must be equipped with a standard set of tools. This tool set must comprise the normal tools for electronic and electromechanical tasks, such as screwdrivers, pliers, spanners, a cable stripper etc. Each tool must be provided in various sizes. We recommend that all tools are demagnetized to protect your equipment.
The following tools and consumables are required.
•  Fish tape (wire pulling tool) with suitable length
•  Electrician’s tape
Context
All necessary precautions must be made to avoid damage to the cables while pulling them through the steel conduit.
Note
Make sure that all welding has been finalized before you pull the cables through the steel conduit. Heat may cause serious damage to the cables and the transducer.
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A Steel conduit
B Watertight seal
C Allow the transducer cables to move freely when the drop keel moves up and down. The cables can be placed inside or outside the drop keel depending on the keel design.
D Secure the cables here.
E Steel conduit
The transducer cables must be properly fastened at the bottom of the drop keel, and fully supported while lowering and hoisting the drop keel. Proper arrangements must be made to handle the cable slack when the drop keel is in its upper position. Depending on the drop keel design, the cable slack can be kept on the outside of the drop keel, or inside it.
The cables must be permitted to move freely when the drop keel is lowered and hoisted. It is important to avoid sharp edges or protruding elements, as these may cause damage to the cables. Observe the limitations for the cable minimum bending radius. Any damage to a cable may cause water ingression. Water follows the cable cores into the transducer, and causes damage that can not be repaired.
Note
Wherever the cables are unprotected outside the drop keel, use a flexible conduit for protection.
Procedure
1 Verify that the steel conduit has been finished, and that all welding has been finalized.
2 Lower the fish tape (wire pulling tool) down from the top of the steel conduit.
3 Fasten the end of the fish tape to the transducer cables using electrician’s tape.
4 Pull the cables carefully up through the steel conduit.
Continue until you reach the Transceiver Unit. Leave some slack close to the Transceiver Unit. Allow the transducer cables to form a service loop close to the transducer.
Note
Be careful! Make sure that you do not damage neither the outer surface of the transducer cables nor the Transceiver Unit connectors. If water leaks into a cable, it may damage the transducer beyond repair.
Wherever the cables are unprotected outside the drop keel, use a flexible conduit for protection.
5 If applicable, seal the top of the steel conduit with a Roxtec (or similar) multi-diameter cable sealing.
6 Inspect the transducer cables as closely as permitted.
a Verify that the transducer cables have not been damaged during installation.
b Verify that the steel conduit used to secure the transducer cables does not have sharp edges or protruding items that may cause damage.
c Verify that enough slack has been provided for the transducer cables to allow maintenance and replacements.
d Verify that the cables can move freely during lowering and hoisting of the drop keel.
e Verify that there are no sharp edges or protruding elements that may cause damage to the cables during lowering and hoisting.
f Verify that the cables are not bent too tightly under during lowering and hoisting.