4.3 MOMENT LIMITER (OVERLOAD PREVENTION DEVICE) M A E D A Crawler Crane
4-32 5/2020 CC1908S-1
OVERRIDE SWITCH
DANGER
The override switch has a function to disable
the moment limiter.
During the three minutes after this switch is
turned on, the crane will not be automatically
stopped by the moment limiter and is in a very
dangerous state. Any crane operation in this
state may result in dropping the hoisted load,
damaging the crane boom, and/or toppling the
machine and may cause a serious accident
resulting in death or serious injury.
Use this switch only when the moment limiter
has failed or during crane load testing. The
key for this switch should be removed during
regular crane operation.
The following operations in particular must
never be performed:
• Never wind up the hook to hoist a load while
this switch is turned on.
Even if the weight of the hoisted load
exceeds the rated total load, this will not be
detected by the moment limiter and could
result in dropping the hoisted load, damage
to the boom, or machine toppling due to the
winch wire rope breaking.
• Never hoist, lower the boom, or extend the
boom with this switch turned on after the
moment limiter has detected that the rated
total load was exceeded during crane
operation and automatically stops the
operation. This may cause boom damage or
machine toppling.
• Use the hook stowage lever when stowing
the hook. If the Override switch is turned on
to allow hook hoisting, the operation will not
be stopped automatically even if
overwinding occurs, and there is a risk of
damage to the boom and hook block,
damage to the wire rope, or dropping the
load.
Use the override switch only when the moment
limiter has failed or for crane load testing.
• ON (Override): Insert the key into the switch.
Turn the key to the "ON"
position once to cancel the
operation stop function.
• OFF (Auto): The key can be removed or
inserted at this position.
The machine status changes as follows when
the operation stop function is cancelled:
• The working status lamp illuminates in red.
• The switch box LED lights up.
• The buzzer sounds continuously.
• A message appears on the monitor.
• The speed of all machine operations is
reduced.
If the switch is turned to the "ON" position
once, the moment limiter function will remain
cancelled until three minutes have elapsed or
the engine key is turned "OFF", even if the
switch is returned to the "OFF" position.
However, this behaviour may vary depending
on the machine status.
To Next Page
Loading...
