The LT/LTQ series from Shanghai Huali (Xingli) Fluid Control are smart variable-frequency electric actuators combining intelligent and VFD control with adjustable motor torque and speed: LT is multi-turn and LTQ is part-turn, with non-intrusive infrared commissioning and mobile APP support. Reference: Xingli LT/LTQ smart VFD electric actuator installation and commissioning manual.

Terminal Wiring

LT/LTQ comes in three wiring variants by control type — on-off, on-off with feedback, and modulating. Main terminals:

Wiring notes:

• Plug-in double-sealed wiring unit — no rewiring needed during maintenance
• Non-intrusive local operating station mounts on three faces and rotates 90°
• The 8 relay contacts are freely configurable; each can be set NO/NC with its own trigger condition
• Supply type is set in the menu: "AC-380" (three-phase) or "AC-220" (single-phase)

Panel and Operating Modes

Three operating modes:

• Local: panel open/close/stop keys work; choose "jog" or "self-holding". In jog mode the actuator stops when the key is released; in self-holding it runs to the end position or until stop is pressed
• Stop mode (OFF/inhibit): all operations inhibited; parameter setting must be done here
• Remote: follows remote signals; parameter queries only in remote or inhibit mode

Commissioning Procedure

Step 1: Enter setting mode

• Use ESC to switch the actuator to "inhibit"
• Press SET to enter the setup/query main menu with three items: Basic Settings, Advanced Settings, System Settings

Note: all parameter setting must be done in inhibit mode; queries only in remote or inhibit mode. After power-up the actuator restores its pre-outage mode.

Step 2: Basic settings

Basic settings has three sub-items — close setting, open setting, travel setting:

• Close setting: enter with SET, handwheel the valve to fully closed, press SET to save
• Open setting: enter with SET, handwheel the valve to fully open, press SET to save
• Travel setting: enter with SET; the system auto-computes the full-stroke encoder counts. LT/LT+WOG/LT+LZ use a 4-stage encoder (counts 0–131072), max output turns ≤300; LT+MT uses a 5-stage encoder (counts 0–1048576), max output turns ≤2400

Note: if the encoder count reaches its ceiling (4-stage: 131072; 5-stage: 1048576) before the valve reaches full open/close, the required output turns exceed the factory range — consult the manufacturer.

Step 3: Advanced settings (password 9123)

• Select Advanced Settings, press SET, enter password 9123
• Key parameters:

Step 4: Modulating control parameters

• Remote zero: 4 mA command calibration value (apply 4 mA, press OK to save)
• Remote span: 20 mA command calibration value (apply 20 mA, press OK to save)
• Feedback zero: 4 mA feedback calibration value (adjust until feedback reads 4 mA)
• Feedback span: 20 mA feedback calibration value (adjust until feedback reads 20 mA)
• Open/close inertia zone: if modulating overshoots, increase the inertia zone
• Micro-pulse energizing time: if modulating overshoots, decrease it

Step 5: Loop test and verification

• Handwheel the valve to mid-position and switch to local
• Stroke the actuator fully twice locally; confirm no abnormality
• Switch to remote for the DCS loop test
• Send 4 mA from the DCS — valve fully closed; 20 mA — fully open
• Send intermediate values and check feedback matches command
• Verify relay outputs (open indication, close indication, alarm etc.)

Common Faults and Remedies

Related reading: Universal Electric Actuator Wiring & Commissioning Guide; see also the Huali Xingli brand column.