SCR - Viper Safety Relays
SCR-73-
i
The new generation of safety relays from IDEM
Single or Dual channel operation
The Viper Safety Relays range from IDEM are designed to meet the latest safety standards and
offer enhanced LED diagnostics and simplified wiring. Applications include safety interlock
switches, emergency e-stop devices, door guard monitoring.
The Viper Safety Relays range includes output expansion units that can be directly wired to
SCR-73-i safety relay to increase the number of safety output contacts. The expansion modules
are available with either immediate or time-delayed output contacts.
The SCR-73-i internal logic uses force guided relays to achieve cross monitoring, this ensures
that a single fault does not lead to the loss of the safety function and that all faults are detected
at or before the next safety demand.
Monitored Manual or Auto Start/Reset
7 NC safety output contacts
3 NO Auxiliary output contacts
Contactor feedback check
Easy diagnosis of status via 6 LEDs
24Vac/dc operation
Up to PLe, SILCL 3, Category 4
45mm DIN rail mounting
Emergency stop and guard interlock
monitoring
Output expansion units available to
increase number of outputs.
Functional Description
When the control line inputs are closed and the start/reset condition
has been met the safety output contacts close.
The safety relay outputs open when the inputs are de-activated or if
there is a power failure. When dual channel inputs are used it is not
necessary to synchronise switching of the input channels.
When operating in the monitored manual reset configuration the
reset button must perform a make-then-break action before the
safety relay will activate.
External device feedback contacts can be monitored via the reset
loop.
Block Diagram and Connections
A1
Power Supply
S21
Auto Reset
53-54
Safety Output Contact 5
A2
Power Supply
S22
Manual Reset
63-64
Safety Output Contact 6
S11
24Vd.c. Control Voltage
13-14
Safety Output Contact 1
73-74
Safety Output Contact 7
S12
Control Line
23-24
Safety Output Contact 2
81-82
Auxiliary Output Contact 1
S13
Control Line
33-34
Safety Output Contact 3
91-92
Auxiliary Output Contact 2
S10
Control Line
43-44
Safety Output Contact 4
101-102
Auxiliary Output Contact 3
