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1.6.3 MOMENT LIMITER OPERATIONS
The moment limiter is a device for unexpected events. Operations relying on the device will rather incur
danger.
Pay sufficient attention during the operation not to cause auto-stop of the crane.
[1] PROHIBITED ACTIONS AFTER AUTO STOP
The following crane operations are prohibited after the crane has stopped automatically due to
overloading. These operations may cause overturning of the machine or breakage of the boom
and are very dangerous.
• Boom lowering operation • Boom raising operation • Boom extending operation
• Hook raising operation • Crane slewing operation
[2] RECOVERY OPERATION AFTER AUTO STOP
Be sure to switch the engine speed to low speed and perform crane operation carefully if the
moment limiter load factor is 90 % or higher.
Performing crane operation at high engine speed will swing the hoisted load and is very
dangerous, causing overloading and it may break the boom.
1. With load factor of “less than 90 %”
When the hoisting load is less than 90 % of the rated total load, the
working status lamp lights in green, indicating normal operation
status.
2. With load factor of “90 to less than 100 %”
When the hoisting load reaches 90 % of the rated total load
(pre-warning), the working status lamp changes from green to
yellow and the alarm sounds intermittently, notifying the operator
and those around that the hoisting load is close to the rated total
load.
3. With load factor of “100 % or higher”
When the hoisting load reaches 100 % of the rated total load by
continuing the crane operation after exceeding 90 % of the rated
total load (pre-warning), the working status lamp changes from
yellow to red and the alarm now sounds continuously. The
following crane operations will stop automatically.
• Hook raising operation • Boom extending operation
• Boom lowering operation • Boom raising operation
The audible message of “Peep, overloading” will be issued. Furthermore, the LED of “100 %” on the
moment limiter load factor display lights up.
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