The AI/MI series from Shanghai Automation Instrumentation (SAI) covers smart modulating actuators (AI) and on-off actuators (MI). The terminal strip uses a 47-wire design with rich functionality and supports Profibus-DP fieldbus communication. This article summarizes AI/MI terminal wiring and commissioning steps. Reference: SAI AI/MI series actuator manual.
Terminal Wiring
| Terminal | Function | Description |
|---|
| 1、2、3 | Three-phase supply L1、L2、L3 | 380V three-phase |
| E | Protective earth | Protective earth |
| 5、35 | Valve open command | Remote open signal |
| 5、33 | Valve close command | Remote close signal |
| 8、9 | Valve fully-open signal | Open feedback signal |
| 6、7 | Valve fully-closed signal | Closed feedback signal |
Wiring note: jumper terminals 4 and 36.
Commissioning Steps
- Pre-checks: verify supply voltage (380V three-phase) and terminal wiring; operate the handwheel to confirm the mechanism moves freely
- Phase sequence: after energizing, switch to local mode and jog to confirm rotation; if reversed, swap any two supply phases
- Enter setting mode: use the panel keys to enter the parameter menu (see the manual's menu structure)
- Close limit: run the valve fully closed and save the close limit in the menu
- Open limit: run the valve fully open and save the open limit
- Torque: set open and close torque values according to valve characteristics
- Analog calibration: adjust feedback to 4 mA fully closed and 20 mA fully open; also calibrate the 4–20 mA input correspondence
- ESD verification: simulate the ESD signal (terminal 25) and confirm the actuator moves to the preset end position
- Remote verification: switch to remote and verify control and feedback via DCS commands
- Fieldbus verification (if fitted): confirm Profibus-DP communication so the DCS can read actuator status and diagnostics
Related reading: Universal Electric Actuator Wiring & Commissioning Guide.
