Towfish Setup 3-53.3.4 GroundingIt is important that the TPU be well grounded to minimize potential hazards to theoperator and electrical interference from other equipment. A good ground for thesystem is a low impedance, well conducted path to the sea water. Always checkthe quality of the electrical ground. Check that the AC power source ground has novoltage potential with respect to the vessel hull.3.4 Towfish Setup3.4.1 General Rigging Notes and CautionsGrease the waterproof connectors when attaching the connectors at the towfish.Avoid putting excessive grease on the male pins. The silicone grease serves animportant lubricating and corrosion protection function. Use a high quality,nonconducting grease such as Dow Corning DC-4.When connecting the tow cable, make a general inspection of the towfish. Checkthat the retaining screws securing the towfish nose cone and tail section assembliesare tight. Check the tail fins and tow bracket assembly to be sure the retainingscrews and bolts are secure. Tail fin tether cables should be tight to the end of thetail cone. It is important to make sure tail fins are straight and true.Attach the shackle end of the safety cable to the bail grip on the tow cable near thetow cable shackle and clevis pin end to the safety cable tab on the top of thetowfish near the tail. The safety cable must be taut enough so that drag, or thelikelihood of snagging, is not increased, but loose enough so that it does notinterfere with the functioning of the tow shackle.CAUTION Always avoid putting excessive silicon grease on the Subconmale pins. Apply a light coat of grease, and never put grease into thefemale connectors.NOTE The tow cable and not the safety cable must take up the strain of thetow loadCAUTION Serious damage to the towfish electronics may occur if thetowfish is operated on deck for periods longer than fifteen minutes.Between periods of operation, let the sonar cool for fifteen minutes. In hightemperature climates, protect the towfish from direct exposure to the sun prior to andduring operation.
