Maeda D3001, Operation Manual

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M A E D A Mini-Crawler Crane Section 4 – MOMENT LIMITER (OVERLOAD DETECTOR)
3/2019 MC305C-3 4-61
Display of Moment Limiter Error
Messages
The moment limiter performs self-diagnosis on
the moment limiter display unit when an error is
issued by the boom angle gauge, boom length
gauge, pressure sensor, or when a circuit is
opened or a connector is disconnected.
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 5-88.
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 extending operation
• Hook raising operation
• Crane slewing operation
• Boom raising 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 in green,
indicating normal operation status.
Fig. 4-168
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.
Fig. 4-169
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