Manitowoc Grove GRT8120, Operator'S Manual

Page: 116 / 448

OPERATING CONTROLS AND FEATURES GRT8120 OPERATOR MANUAL
3-42
Published 3-22-2021, Control # 702-02
Bridging 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.
The Bridging Switch is located inside a key-locked
single-door enclosure (Figure 3-22) attached to the outside
rear of the operator cab.
The switch is a two-position momentary rocker switch.
During maintenance or troubleshooting work, or to recover
the crane, push and release the switch to bypass the
following limiter systems and their crane function lockouts:
• RCL System (boom up/down, telescope extend, hoist
up)
• Working Range Limiter (WRL) System
• Carrier Avoidance System
The following indicators come on to indicate the limiters are
bypassed:
• Bypass 3 Pressed Indicator is on (only when pushed
and held) (Figure 4-206)
• RCL Bypass Active Indicator is on (Figure 4-206)
• Working Range Limiter (WRL) Indicator is on
(Figure 4-71)
• Low Boom Angle Indicator is flashing (Figure 4-68)
Upon pushing the Bridging Switch, the swing left/right
function pressure is reduced to 25%. The boom down, hoist
up, and telescope extend function speeds are reduced to
15% when actuated. Boom up, hoist down, and telescope
retract function speeds are not reduced.
Overriding the RCL with the Bridging Switch should only be
done in an emergency.
All crane function lockouts are bypassed until one of the
following occurs:
• Bridging Switch is again pushed and released.
• 30 minutes have passed since the Bridging Switch was
initially pushed, and controllers are in the neutral
position.
• Engine is stopped.
WARNING
Overload Hazard!
The Bridging Switch prevents the function lockouts from
activating.
When the Bridging Switch is activated, the operator must
make sure that the crane is not overloaded.
Do not operate crane with RCL overridden during normal
operations.
FIGURE 3-22
7649-36
1