Section 4 – MOMENT LIMITER (OVERLOAD DETECTOR) Mini-Crawler Crane M A E D A
4-70 1/2019 MC405C-3
The result is displayed on the "Rated total load
Display" of the moment limiter display unit by an
error code to notify the operator of the error.
Immediately stop the use of the crane when an
error code is displayed.
See "Moment Limiter Error Causes and Actions
to Be Taken" on page 5-94.
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.
Prohibited Actions After Auto Stop
DANGER! 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
Recovery Operation After Auto Stop
DANGER! 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 slew 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.
Fig. 4-180
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, notifying the operator and those around
that the hoisting load is close to the rated total
load.
Fig. 4-181
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
Fig. 4-182
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