Furuno CH-270 - Manual (Page 106)

6. MAINTENANCE, TROUBLESHOOTING
6-2
6.3 Hull Unit Maintenance
6.3.1 Lubrication
Coat the raise/lower screw shaft once a year with Molytone grease. Also, grease the
raise/lower main shaft (upper part of the grease cotton retainer) twice a year.
6.3.2 Manually raising, lowering transducer
WARNING
Turn off the power at the ship's mains
switchboard before conducting the
procedure below.
Moving parts can cause bodily injury.
Hull unit CH-181
1. Turn off the breaker on the hull unit and unplug the connector on the motor lead wires
in the hull unit. (This will make raising and lowering of the soundome easier, because
the motor which works as a generator will be isolated from the load.)
2. Remove the top cover of the raise/lower drive assy. and attach the hand crank as
shown below.
Hand Crank
Unplug connector
on lead wires
Hull unit, top cover of raise/lower assy. opened
3. Turn the hand crank to check that the transducer rises and lowers smoothly, from the
upper to the lower limit positions. If the transducer cannot be raised smoothly, do not
use force; the shaft may bend.