MAINTENANCE 4.9 EVERY 50 OPERATING HOURS OR WEEKLY 4.9.4 HYDRAULIC ACCESS LADDER - CHECK SAFETY SENSOR Legend for illustration Z 21532 (A) Access ladder in lowered position (B) Access ladder in upper position (Working position) (C) Stop bar (D) Manual actuator for fire suppression system (S84) Ladder control switch at the radiator door Switch positions: 0 - OFF 1 - Lifting the Ladder 2 - Lowering the Ladder (S22) Safety sensor, located on ladder pivot bracket Function of sensor (S22): Cut out of the pilot control system and actuation of the hydraulic slew brake with the ladder in lowered position. (S91) Monitor and control sensor Function of sensor (S91):
This sensor monitors the ladder position and con- trols the moving speed of the ladder. In case the sensor (S22) fails to function properly, the sensor (S91) prevents unintended movement of the ladder. (S33a) Emergency shutdown switch for engine Check Safety Sensor (S22) as follows: With the ladder completely lowered (position A) start the engine. Hold an iron part (screw driver) in front of sensor (S22). The ladder must not start to move. If the ladder starts to move, immediately remove the iron part from the sensor. G Inform the Service Staff about the malfunction of the lad- der sensor. G DO NOT operate the Excavator prior the failure has been eliminated and the sensors function properly.
343 WARNING