Cable splice - Faults and links

Common faults

Fault origins can vary: blown fuse, power supply fault, failed solder joint, poor insulation, damaged cable, faulty slip ring or junction box in poor condition.

If an instrument connected to the electromechanical cable malfunctions, start by:

• checking the fuses
• testing the instrument directly with a test cable, without going through the electromechanical cable
• checking the visible condition of the connectors and the splice

If the instrument works correctly in direct connection, the problem is probably in the electromechanical cable + slip ring + splice + connectors chain. Then:

• check that the supply voltage is present at the wet-mate connector terminals
• check current flow, because a broken solder joint can show high resistance
• check the slip ring
• inspect the junction boxes
• test cable insulation with a megohmmeter

A mechanically correct but poorly insulated splice can work in open air and become unstable under pressure or after a few immersions. Checks must therefore be done methodically and recorded in the instrument logbook.

Useful links

• Electromechanical cable: Schlumberger Vector SA
• Electromechanical cable, reference 1-42P
• Scotchfil
• Scotch 23
• Scotch 33+
• Galvanized cable grip socket
• Claw-type cable grips SIMEL DA100
• Impulse cable, reference RMG2FS
• Sea Con cable, reference RMG-2FS
• Crosby
• Megohmmeter Fluke 1503
• Crosby closed spelter socket, reference G416
• Crosby open spelter socket, reference G417
• Wirelock resin
• Supplies: Radiospares online catalog
• 911plus CTD and LADCP operating procedure

Some of these links are old and may have changed since the original article was published. During final validation, the external links should be checked and broken references should be replaced by current manufacturer or distributor pages whenever possible.

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