The Bernard ST series actuators carry open/close limit switches, torque-limiting switches in both directions (against momentary overload), a mechanical position indicator and a handwheel for operation without power; each unit is adjusted, tested and inspected before shipment with long-life lubrication, and mounts in any orientation. This manual (Chinese, 5 pages) gives the complete field commissioning procedure.
| Step | Action | Key points |
|---|---|---|
| 1-1 Anti-condensation heater (option) | Power the heater as soon as the actuator arrives on site | Prevents condensation; recommended for all actuators |
| 1-2 Handwheel | ST series (except ST6) has motor-priority auto-declutch, direction marked on the wheel | ST6 has a clutch knob: align the arrow with the triangle (turn the wheel slightly if it will not engage); disengages automatically on motor start |
| 2 Electrical checks | a) supply data b) wiring c) valve to half-open by hand d) connect limit & torque switches, check function e) jog to verify rotation matches the order | If wrong, reverse the direction; verify the mechanical indicator before closing covers |
| 3 Cam-group limit setting | 4 independent cams: 1 = white, 2 = black (limit switches); 3 = brown, 4 = grey (auxiliary); press the screw with the cam-color collar, push down to unlock, rotate until the switch just actuates, release to re-lock | Cylindrical cam group needs no disassembly; ensure the screw reseats fully |
| 4 Torque switches | Factory-set to the ordered torque value; if it trips, check stem cleanliness/lubrication, stem-nut seizure, gland packing too tight | To adjust: open the limit-switch mechanism, turn the adjuster screw, read % on the scale; 100% = actuator reference torque |
伯纳德-ST系列调试手册.pdf (Chinese, 5 pages)
An industry resource for electric & pneumatic actuators, dampers and heaters: brand manuals, sizing guides and maintenance know-how. Global brands in, China manufacturing out.
