Application examples for conventional PSRclassic safety relays
102597_en_03
PHOENIX CONTACT
5.5
Two-hand control
According to EN 574, the simultaneity of two-hand control devices must be monitored to be
< 0.5 seconds. The time is reliably checked and evaluated by corresponding category type
III modules.
Two-hand control devices are localized safety equipment. The operator must keep his/her
hands on the control device during dangerous machine movements.
Figure 5-24
Two-hand control design
Manual control
e.g., emergency stop button
Control device
Input command
Synchronous actuation
Initiation of the 1st
input signal
Initiation of the 2nd
input signal
Cessation of the
input signals
1st hand
2nd hand
.
Synchronous
actuation
Time period for
simultaneous actuation
Time
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