Anti-Two-Block (A2B) Switch; Locking; Unlocking - Manitowoc Grove GRT655 Operator's Manual

GRT655/655L OPERATOR MANUAL

ANTI-TWO-BLOCK (A2B) SWITCH

If a single hoist rope has been reeved and two A2B switches
are installed, the unused A2B switch must be locked
(disabled) to allow all crane operations.

Locking

DANGER
Two-Block Hazard!
To avoid death or serious injury, keep load handling
devices away from the tip of the boom or boom extension
when extending the boom and when hoisting up.
If the A2B switch is locked (disabled), the hook block
could hit the main boom head or extension. Never lock an
A2B switch when a hoist rope is installed to that
attachment.
1. Remove A2B weight.
2. (A) Remove cap (1) from switch.
3. Pull lanyard (2) down.
4. (B) Secure lanyard (2) in this position using cap (1).
A2B switch is locked (disabled).
8684-1
Grove

Unlocking

Failure to reposition the A2B weight will prevent the A2B
system from functioning properly. No weight shall be
mounted on the A2B switch of the main boom when
working with the extension.
NOTE:
1. (A) Pull down lanyard (2) and remove cap (1). Switch is
unlocked (enabled).
2. (B) Install cap (1) on A2B switch.
8684-2
FIGURE 5-8
Published 3-23-2020, Control # 654-04
SET-UP AND INSTALLATION
WARNING
Always remove the switch lock (enable) before
installing an A2B weight around the hoist rope.
FIGURE 5-9
5
5-7