Rockwell Automation 440G-LZ Guard Locking Switch User Manual - Manual (Page 7)

Rockwell Automation Publication 440G-UM001A-EN-P — November 2013 7
Chapter
1
General Description
Guardmaster 440G-LZ
Overview This Guardmaster 440G-LZ guard locking switch functions by extending a
locking bolt from the switch through a hole in the actuator, thus
preventing the opening of a guard.
The locking bolt drive mechanism and logic ensure that the locking bolt
is allowed to extend only when the corresponding actuator is detected
within range.
The appropriate actuator is detected by RFID coding.
This version of the Guardmaster 440G-LC guard locking switch features
OSSD outputs that are enabled only when the locking bolt is sensed in its
extended position in the actuator, which happens only when the guard is
both closed and locked.
The locking bolt drive mechanism uses a bi-stable solenoid; as a result,
the switch consumes very little electrical power, with peak currents
occurring only briefly, upon start-up and after each movement of the
locking bolt.
Because of its bi-stable drive, not only does the device consume minimal
power, but it does not produce heat whether in its locked or unlocked
condition.
Despite the bi-stable design of the locking bolt drive, the device logic and
functionality are configured to replicate the functionality of a power-to-
release or power-to-lock solenoid-operated switch (depending on type).