The installation of electric actuators must strictly follow the process of "safety inspection → positioning and fixing → connection and debugging". The core is to ensure accurate mechanical docking and standardized electrical wiring, and to avoid jamming or faults during operation. The following are specific operating steps applicable to common driving scenarios such as valves and dampers.
1、 Preparation before installation: 3 core checks
Equipment and working condition matching inspection
Confirm that the model, torque, and stroke (such as 0-90 ° angle stroke and 0-500mm straight stroke) of the electric actuator are consistent with the parameters of the controlled equipment (valve/damper) to avoid insufficient torque causing inability to drive or overload damage.
Check whether the protection level (such as IP65, IP67) and explosion-proof level (such as ExdIIBT4) of the actuator meet the on-site environment (such as humid and explosion-proof areas). If they do not meet the requirements, the compatible model needs to be replaced.
Preparation of accessories and tools
Accessories: Prepare compatible connecting flanges/couplings, bolts (strength grade ≥ 8.8), sealing gaskets (such as oil resistant rubber pads, metal winding pads), wiring terminals, waterproof sleeves, etc.
Tools: torque wrench (used to fix bolts), level gauge (used to calibrate installation levelness), multimeter (used to detect electrical circuits), insulation tape, screwdriver, etc. Explosion proof tools are required for explosion-proof scenarios.
Safety protection measures
Cut off the power and air supply (if any) of the controlled equipment (valves/dampers) and actuators, and hang a "Do Not Close" sign at the power switch to prevent electric shock caused by misoperation.
If there is a medium on site (such as chemical fluids, steam), the upstream and downstream valves should be closed first, and the medium in the pipeline should be emptied to avoid safety accidents caused by medium leakage during installation.
2、 Mechanical installation: 4-step precise docking
Positioning and fixing of controlled equipment
First, fix the valve/damper on the pipeline or equipment, ensuring that its installation position is level (calibrated with a spirit level), to avoid uneven force on the actuator due to its own inclination.
If the actuator and the controlled equipment are connected by a flange, it is necessary to ensure that the flange holes of both are completely aligned, and the parallelism error of the flange surface is ≤ 0.1mm to prevent jamming after installation.
Connect the actuator to the controlled device
When using a coupling connection: Place the coupling separately on the actuator output shaft and the controlled equipment shaft, ensuring that the coaxiality error of the two shafts is ≤ 0.05mm (which can be checked with a dial gauge), tighten the coupling fixing screws (torque according to the instructions), and avoid slipping during operation.
When using flange connection: Place sealing gaskets between the flanges, insert bolts and tighten them according to the principle of "diagonal uniform tightening" (torque reference manual, such as M12 bolt torque of 30-35N · m) to prevent medium leakage or flange deformation.
Fixed actuator body
Fix the actuator base on the preset bracket or foundation, and the bracket should be firm (with a load-bearing capacity of ≥ 2 times the weight of the actuator), and the actuator should not tilt after installation (with a horizontal error of ≤ 0.5 °), to avoid component loosening caused by vibration during operation.
If there is vibration on site (such as near the pump body), vibration damping pads (such as rubber pads) need to be installed between the actuator base and the bracket to reduce the impact of vibration on the internal gears and motors of the actuator.
Mechanical clearance inspection and adjustment
Manually rotate the handwheel of the actuator (or use a manual control lever) to drive the controlled equipment (valve/damper) to run in full stroke 1-2 times, check for any blockages or abnormal noises, and ensure smooth operation.
If there is a blockage, it is necessary to readjust the coaxiality of the two axes or the parallelism of the flange; If there is a deviation in the stroke (such as the valve not fully closed/fully open), the stroke limit position should be marked and calibrated during subsequent electrical debugging.
3、 Electrical wiring: 5 standard operations
Circuit detection before wiring
Use a multimeter to check whether the power circuit of the actuator (such as AC220V, DC24V) is powered off, and whether the signal line (such as 4-20mA control signal) has no voltage, in order to avoid short circuits during wiring.
Check whether the terminals inside the actuator junction box are intact, whether they are loose or oxidized, and whether the sealing rubber ring is intact (to prevent water ingress). If damaged, replace them before wiring.
power wiring
According to the electrical schematic in the actuator manual, connect the power cord (live wire L, neutral wire N, ground wire PE) to the corresponding power terminal. The ground wire must be reliably grounded (grounding resistance ≤ 4 Ω) to prevent leakage and electric shock.
If the actuator is a three-phase power supply (such as 380V), confirm that the power supply phase sequence is correct to avoid reverse rotation of the motor (the phase sequence can be adjusted after the test run).
Control signal and feedback signal wiring
When connecting control signals (such as 4-20mA analog signals and switch control signals output by PLC), shielded wires should be used for the signal lines, and the shielding layer should be grounded at one end (connected to the grounding terminal of the control cabinet) to avoid electromagnetic interference.
Connect feedback signals (such as 4-20mA position feedback and switch status signals output by actuators), ensure that the signal line is laid separately from the power line (with a spacing of ≥ 100mm), and prevent signal drift.
Wiring fixation and sealing
After tightening all wiring terminals, the exposed parts should be wrapped with insulating tape to prevent short circuits; Excess wires need to be sorted and fixed to avoid touching the moving parts of the actuator.
Tighten the junction box cover to ensure that the sealing gasket is tightly pressed. If the site is damp or has corrosive gases, waterproof sleeves should be installed at the inlet and outlet of the junction box to ensure proper sealing.
Electrical circuit insulation test
Use an insulation resistance meter (shaking table) to test the insulation resistance between the power circuit and the grounding circuit, with a requirement of ≥ 5M Ω (at room temperature and pressure). If the insulation resistance is too low, check whether there is a short circuit or moisture in the wiring, and eliminate the fault before proceeding to the next step.