Fail Safe

Fail Safe Switch

The Fail-Safe Switch is used in all Unimax interlocks, available in one, two and three pole units as standard with larger switch banks available upon request. These positive-break, fail-safe, load switching controls may be purchased without any additional hardware.

This component was made famous as part of an iconic costume design in the blockbuster sci-fi film trilogy: Star Wars.

The switch components are housed in a Zytel flame retardant nylon 66/6 Copolymer with 25% glass reinforced case (compliant with UL94V-0). The large heavy-duty contacts are mounted on an actuator which is directly driven by a cam. The contacts open to a 4mm air gap, in compliance with VDE and other main isolation standards .Switches are rated 25A 250AC Manufacturer's rating UL / CSA approval 15A 480V AC.

Fail-safe features: The contacts are forced open by positive cam action. If the contacts weld the secondary contacts open and a shearing action then breaks the weld. Should a spring break, the contacts would still open, the design prevents any short-circuiting by a spring fragment.

INDEXED CAM SHOULDER SWITCH

Indexed Cam fail safe switches are equipped with a mounting collar drilled for two blind roll pins used to lock the switch in place with 3 operating positions 60 degrees apart. This switch is specific to the GW and SAF interlock ranges.

 SS switch type drawing

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  Switch block configurations

TYPE POLE PART NUMBER POSITION 1 POSITION 2 POSITION 3
SPST 1 SS/11 OFF OFF ON
DPST 1 SS/21 OFF OFF ON
2 OFF OFF ON
DPST 1 SS/22 OFF OFF ON
2 ON ON OFF
3PST 1 SS/31 OFF OFF ON
2 OFF OFF ON
3 OFF OFF ON
3PST 1 SS/32 OFF OFF ON
2 OFF OFF ON
3 ON ON OFF
3PST 1 SS/33 OFF OFF ON
2 ON ON OFF
3 ON ON OFF

 NON LOCKING ON/OFF SWITCH

Non locking fail safe switches have a dwell position of 15 degrees in which the switch is ON and 345 degree sector in which the switch is OFF. This switch is specific to the Hinge and Link systems.

 GW0 switch type drawing

  Switch block configurations

TYPE POLE PART NUMBER 356 SEGMENT 4 SEGMENT
SPST 1 GW011 OFF ON
DPST 1 GW021 OFF ON
2 OFF ON
DPST 1 GW022 ON OFF
2 OFF ON
3PST 1 GW031 OFF ON
2 OFF ON
3 OFF ON
3PST 1 GW032 ON OFF
2 OFF ON
3 OFF ON
3PST 1 GW033 ON OFF
2 ON OFF
3 OFF ON

 Special cam configurations available on request.