1-20. CRANE (CONT).
Overload Shutdown. The crane is provided with an overload shutdown (1) which prevents structural
overloading. Two block and overload conditions are sensed through line-pull of the hoist. A preprogramed
microprocessor that is constantly comparing boom angle, boom length and hoist line pull, activates solenoid valves to
prevent telescope out, lift up, lift down and hoist up functions when unit is overloaded or two-blocked. During an
overload condition, the cranes functions cease except for hoist down.