Configuration Setup
© PAT Revision E // SB // 09/03/02
190137_E
17
4.4 Anti-two Block (A2B) Switch(es)
All RT875CC cranes are provided with two different configurations of A2B switches.
Correct use of the A2B switches must be followed to prevent material damage and serious
or even fatal accidents. The applications under which these switches are used are
described below:
a. Main Boom A2B Switch
The main anti-two block switch is used in all main boom applications (movements and
lifts). This switch is used in conjunction with a chain and the weight around the main
hoist cable. A by-pass flag must be installed in the auxiliary boom nose A2B switch during
main boom operation.
Without the flag installed crane functions will remain locked out.
b. Auxiliary Boom Nose A2B Switch
The auxiliary anti-two block switch is used in auxiliary boom nose applications
(movements and lifts). This switch is used in conjunction with a chain and the weight
around the auxiliary hoist cable. A by-pass flag must be installed in the main boom A2B
switch during auxiliary boom nose operation.
Without the flag installed crane functions will remain locked out.
The anti-two block switch must be used in ALL Operations. Simultaneous two-
hoist working is prohibited in all circumstances.