Honeywell SYA14 Series Manual page 53

4.5.2 Protection of Machine Stop Contacts
The OSSD1 and OSSD2 outputs must be protected by an external 1.5 A max. fuse. It is
also recommended to connect 31 Vdc varistors in parallel with the FSDs relay coils.
•
Use of RC circuits accross the loads will prevent the light curtain from operating.
IMPROPER PROTECTION INSTALLATION
•
Never install varistor across the fail safe static output of the light curtain.
•
Always install varistors across the coils of the external safety relays.
•
Use fuses with the correct rating to protect the safety outputs.
Failure to comply with these instructions could result in death or serious injury
4.5.3 Connection to the machine control circuitry
It is necessary to connect the terminal 3 to the +24V to energize the relays K1 and K2
through the OSSD1 and OSSD2 outputs. The switching capacity of the static output
(0.5A/24Vdc) combined with the number of available outputs displayed by the equipment
(2 Normally Open outputs) means that the equipment may be connected to two external
relays with guided contacts K1 and K2 (usually called « Final Switching Devices » -
FSDs). These FSDs must be regularly controlled.
•
It takes 160 ms for the light curtain to restart after each beam release.
IMPROPER EXTERNAL SAFETY RELAYS PERFORMANCE
•
Use three independent stop circuit safety relays K1, K2 and K3 with mechanically
linked contacts (such as GE CR120 BP Machine Tool Relay or Telemecanique CA3-
KN31BD3 or CA3-DN31BD relay) to reliably detect a welded contact.
Failure to comply with these instructions could result in death or serious injury
107031-23 EN FR26 GLO 1199 Printed in France 53