Manitowoc Grove GRT8120, Operator'S Manual

Page: 84 / 448

OPERATING CONTROLS AND FEATURES GRT8120 OPERATOR MANUAL
3-10
Published 3-22-2021, Control # 702-02
Momentary Limit Bypass Switch (Non-CE
Certified Cranes)
T h e R a t e d C a p a c i t y L i m i t e r ( R C L ) s y s t e m , w h e n
programmed accurately, will lock out the following crane
functions—boom up/down, telescope extend, and hoist up—
when a lift is attempted at or above crane capacity, or when a
two-block condition exists.
Locking out these functions prevents the overload or
two-block condition from worsening.
These same crane functions are locked out initially after the
crane engine is started and before the RCL system has been
programmed.
The Limit Bypass Switch (13, Figure 3-3) is a three-position,
momentary type rocker switch located on the right overhead
control panel.
During certain rigging work or to recover the crane, push and
hold the top or bottom of the rocker switch to bypass the
following limiter systems on the crane.
Push and hold bottom of rocker switch to bypass the
following limiter systems and their crane function lockouts:
• Anti-Two-Block System (boom up/down, telescope
extend, hoist up)
• 3rd Wrap Limiter System (hoist down)
The following indicators come on to indicate the limiters are
bypassed:
• Anti-Two-Block Indicator is flashing (7, Figure 3-6)
• 3rd Wrap Alert is flashing (Figure 4-68)
Push and hold top of rocker switch to bypass the following
limiter systems and their crane function lockouts:
• RCL System (boom up/down, telescope extend, hoist
up)
• Anti-Two-Block System (boom up/down, telescope
extend, hoist up)
• 3rd Wrap Limiter System (hoist down)
• Working Range Limiter (WRL) System
• Carrier Avoidance System
• -29°C Temperature Limiter System (optional)
The following indicators come on to indicate the limiters are
bypassed:
• Bypass 1 Pressed Indicator is on (Figure 4-206)
• RCL Bypass Active Indicator is on (Figure 4-206)
• RCL Shutdown Warning Indicator is flashing
(5, Figure 3-6)
• Anti-Two-Block Indicator is flashing (7, Figure 3-6)
• 3rd Wrap Alert is flashing (Figure 4-68)
• Working Range Limiter (WRL) indicator is flashing
(Figure 4-71)
• Low Boom Angle Alert is flashing (Figure 4-68)
• -29°C Temperature Limiter Alert is flashing (Figure 4-68)
All crane function lockouts are bypassed while the Limit
Bypass Switch is held in the actuated position.
Limit Bypass Set-Up Switch (CE Certified
Cranes)
T h e R a t e d C a p a c i t y L i m i t e r ( R C L ) s y s t e m , w h e n
programmed accurately, will lock out the following crane
functions—boom up/down, telescope extend, and hoist up—
when a lift is attempted at or above crane capacity, or when a
two-block condition exists.
Locking out these functions prevents the overload or
two-block condition from worsening.
These same craning functions are locked out initially after
the crane engine is started, and before the RCL system has
been programmed.
The Limit Bypass Set-up Switch (13, Figure 3-3) is a
three-position, momentary type rocker switch located on the
right overhead control panel.
During certain rigging work or to recover the crane, push and
release top or bottom of rocker switch to bypass the following
limiter systems on the crane.
WARNING
Overload Hazard!
The Limit Bypass Switch is used to override the RCL
system during some rigging activities.
When the Limit Bypass Switch is activated, the operator
must make sure that the crane is not overloaded.
Do not operate the crane with the RCL overridden during
normal operations.
WARNING
Overload Hazard!
The Limit Bypass Switch prevents the function lockouts
from activating.
When the Lift Bypass Switch is activated, the operator
must make sure that the crane is not overloaded.
Do not operate the crane with the RCL overridden during
normal operations.