SAI AI/MI Series Electric Actuators: Terminal Wiring & Commissioning

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.