Quarter-Turn Rotary Electric Valve Actuator
We supply 35–5,000 Nm quarter-turn rotary electric valve actuators that adapt to linear valves with an add-on LT Lifter, helping you eliminate duplicate stock.
Quarter-Turn Rotary Electric Valve Actuator
Item Number: HUS Quarter-Turn Series
Motion & Travel: 0°–90° Quarter-Turn Rotary (Standard) | Custom 180° / 270° / 360° Rotary (Optional) | 30–100 mm Linear Stroke (with LT Lifter)
Torque & Thrust: 35–2,300 Nm direct (up to 5,000 Nm with gearbox) | 2–45 kN linear thrust
Power Supply: 24V DC, 110V / 220V AC (1Ph), 380V / 400V / 440V AC (3Ph), 50/60 Hz
Control Modes: On-Off, 4–20mA Modulating, Non-Intrusive Intelligent (ICM)
Bus Protocols: Modbus, Profibus, HART
Temperature Range: ON/OFF: -20°C to +70°C | Modulating / ICM: -20°C to +55°C
Enclosure Rating: IP67 (Standard Weatherproof), Optional IP68 / Exd IIC T6 Gb
Mounting Standard: ISO 5211 direct mounting interface
Manual Override: Spanner / Push Hand Wheel Operation / Clutch Less Hand Wheel
- Certifications: IECEx, ATEX, ISO 9001, CE, SIL3
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Custom Actuator Housing Color
We customize quarter-turn rotary electric valve actuator housing colors (RAL/Pantone) with durable epoxy powder coating to match your corporate brand identity, system color-coding, or specific project aesthetic requirements.
Custom OEM Label
We offer private label solutions for distributors and OEM valve makers. Choose corrosion-resistant metal plates (stainless/aluminum) with laser-etched logos, or high-tack weatherproof industrial stickers.
18-Month Factory Warranty
Every quarter-turn rotary electric valve actuator includes an 18-month warranty from the shipment date, providing a 6-month buffer beyond industry standards for ocean transit, customs clearance, and warehouse stocking.
Description of HUS Series Quarter-Turn Rotary Electric Valve Actuator
HEARKEN HUS series quarter-turn electric valve actuators deliver precise 0°–90° rotary control for industrial ball, butterfly, and plug valves. Standard models provide direct output torque, extendable up to 5,000 Nm via modular secondary gearboxes. Fully IECEx and ATEX certified, the series delivers reliable flameproof and dust-ignition protection for demanding hazardous environments.
Specifications & Features
Wide-Voltage Power Supply
85–265V AC/DC Models: Auto-adapt across 110V, 120V, and 220V grids (AC or DC) on the same actuator without manual switches.
24V AC/DC Models: Run on either 24V AC or 24V DC on the same actuator.
Three-Phase Models: Support 380V/400V/440V AC (50/60 Hz) for heavy industrial lines.
- Motor Protection: Totally enclosed Class F motor with low rotational inertia and built-in thermal overheat protection.
- ±10° Travel Adjustment: Screws on the back let you adjust travel by ±10° without removing the quarter-turn rotary electric valve actuator from the valve.
- Split-Type Remote Mounting: Supports split-type configuration that isolates the electronic control module from the valve drive, designed for extreme temperatures, heavy pipeline vibration, and hazardous confined spaces.
- High-Torque Eccentric Planetary Drive: Runs under 50 dB and self-locks against back-pressure. By combining internal planetary gears with a high-power motor, it outputs up to 30% more torque than standard worm gear models in the same housing size.
| Performance | Eccentric Planetary Drive | Standard Dual-Worm Drive |  |
| Gear Engagement | Multi-tooth engagement | Single-tooth engagement | |
| Efficiency | High | Low | |
| Torque Output | High | Low | |
| Control Range | 0°–360° | 0°–120° |
Control Types
| Model Type / Configuration | Key Features | Typical Uses | |
| HUS On/Off Type | • Full open and full close control using external switch signals. | Pump discharge shutoff, tank emergency isolation, and general water treatment lines. |  |
| • Top mechanical dial shows valve position clearly. | |||
| • Dry contact limit switches send open/close feedback. | |||
| • Supports optional potentiometer (0–1kΩ / 0–5kΩ) or 4–20mA feedback board. | |||
| HUS Modulating Type | • Continuous positioning via standard 4–20mA / 0–10V input. | Heat exchangers, temperature control, line pressure balance, and continuous throttling loops. |  |
| • 4–20mA active position feedback (basic error ≤±0.2%). | |||
| • Absolute encoder saves position during power loss without a battery. | |||
| • 4 push buttons on internal board for one-touch zero/span setup. | |||
| • Built-in stall cutoff, reverse-run delay, and signal-loss safety action. | |||
| • Supports optional Modbus communication. | |||
| HUS Intelligent (ICM) Type | • Dual control: supports both 4–20mA analog and switch/jog inputs. | Digital DCS/PLC networks, automated plants, and sites requiring non-intrusive setup with live diagnostics. |  |
| • Non-intrusive setup via remote control or external knobs (no cover opening). | |||
| • LCD screen shows opening percentage, control mode, and error text. | |||
| • Power-on auto self-check, dynamic braking, and 3-phase phase correction. | |||
| • Dry contact outputs for open, close, fault, high torque, and remote/local status. | |||
| • Supports optional Modbus, Profibus, and HART communication. |
Select Control Configuration & Get Direct Factory Pricing
Whether you need basic On/Off line isolation, 4–20 mA proportional throttling, or digital fieldbus integration, we supply factory-tested quarter-turn rotary electric valve actuators ready for direct valve assembly.
Applications
The HUS series delivers precise quarter-turn automation across diverse working conditions:
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Optional Accessories
| Add-on / Accessory | Description | Function / Typical Application |
| Space Heater | Internal anti-condensation heater with auto switch | Stops moisture buildup inside the housing in high-humidity or cold outdoor sites. |
| Potentiometer Feedback | 0-1 kΩ or 0-5 kΩ continuous resistance output | Provides real-time resistance position signals to external meters or control boards. |
| Mounting Brackets & Drive Adapters | ISO 5211 standard brackets, high-temp standoffs, and drive inserts | Adapts the actuator to ISO 5211 top flanges, rising stems, or custom valve shafts. |
Customization & Engineering Options
Custom Rotation Angles: 0°–120°, 0°–180°, and 0°–270° stroke options for 3-way/4-way valves and dampers.
Extreme Temperature Solutions: Low-temperature seals for sub-zero sites, plus extended brackets and thermal spacers for line temperatures above 100°C/180°C.
Private Label & Nameplates: Stainless steel plates, plastic nameplates, or printed stickers with custom brand logos, company model numbers, and serial numbers.
- Custom Housing Colors: Polyester powder coating matched to RAL codes for piping standards (blue, grey) or OEM brand colors.
LCD Display & Menus (ICM Intelligent Type)
The HUS ICM intelligent quarter-turn rotary electric valve actuator has an LCD screen on the control panel. It uses simple text, color icons, and pipe graphics to show live valve position and working data. You can set up the quarter-turn rotary electric actuator and change all settings with the cover closed.
| Display Screens & Status | Menu Setup | Startup Self-Check & Protection |
| Main Screen: Shows live valve position (0.0% to 100.0%), motor state (Run / Rest / Stop), working current (A), and animated pipe flow. Fully Closed Screen: Shows a red valve icon and a closed pipe line to confirm full shutoff. Fully Open Screen: Shows a green valve icon and an open pipe line to confirm full flow. Main Menu: Lets you adjust settings using the remote control or outer knobs without opening the cover. | Debug Menu: Sets zero and full open positions with one-button auto setup. Function: Adjusts run speed, deadband, motor brake, and signal-loss action (open, close, or stop). Signal Set: Selects control input: 4–20 mA analog, switch contacts, or fieldbus (Modbus, Profibus, HART). Query Menu: Reads out total run cycles, motor heat, and saved fault records. | Power-On Test: Checks system memory, input circuits, and signal converters every time power turns on. Fault Stop: If the system finds a problem, the screen shows the exact fault message and stops the motor until it is fixed. |
HUS + Lifter: Modular Linear Conversion
The LT series linear lifter (LT-1, LT-2, LT-3) is designed for the HEARKEN HUS quarter-turn electric actuator. Mounts directly to the base of the HUS quarter-turn rotary electric valve actuator and uses an internal screw-and-nut mechanism to convert the 90° rotary motion into linear push and pull thrust.
Combining the LT lifter with the HUS quarter-turn rotary electric valve actuator allows you to operate rising-stem linear valves—including globe valves, cage control valves, and linear diaphragm valves—without requiring a dedicated linear electric actuator.
How the HUS + Lifter System Works
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HUS + Lifter Advantages
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Typical Valve Applications
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Complete HUS Product Line
Need to automate other valve types? In addition to our electric actuator with linear lifter kits, the HUS range includes:
HUS Linear Series: Linear electric actuators for long-stroke and high-thrust control valves.
Looking for dedicated linear valve drives instead of bolt-on lifter kits? Browse the Linear Electric Actuator Catalog →
HUS Multi-Turn Series: Multi-turn electric actuators for gate valves, knife gates, and manual gearboxes.
- HUS Spring-Return Series: Mechanical spring-return fail-safe actuators that reset valves to safe open or closed positions during power loss, built for emergency shutdown (ESD) lines.
Ready to Automate The Valves with HUS Quarter-Turn Rotary Electric Valve Actuator?
Get direct factory pricing, 2D/3D CAD mounting files, and verified torque sizing support today.
HUS vs Other Hearken Quarter-Turn Electric Actuator Series
Compare mechanical builds, torque ranges, and control features across our quarter-turn electric actuator series to find the right model for your valve automation requirements.
| Features & Capabilities | HUS | HQT | HEA |
| Fully modular design for easy functional expansion and simple maintenance | ● | ● | ○ |
| Explosion-proof housing (Ex d IIB T4) with IP67 ingress protection | ● | ● | ○ |
| Worm gear drive with mechanical self-locking function | ● | ● | ● |
| Clutchless manual override for easier, safer field operation without switching levers | ● | ○ | ○ |
| Over-torque protection to protect the motor and valve during stall conditions | ● | ● | ○ |
| Integrated smart controls available to meet advanced process and bus requirements | ● | ● | ● |
| Splined output drive shaft to adapt to various valve stem connections | ● | ● | ● |
| Standard modulating models feature internal LED displays for fault codes and wider voltage options | ● | ○ | ○ |
| Higher torque & mechanical strength, with output torque up to 4,000 Nm | ● | ○ | ○ |
| High-speed fast-operating options available without reducing mechanical service life | ● | ○ | ○ |
Need Help Selecting Between HUS, HQT, and HEA Quarter-Turn Rotary Electric Valve Actuator?
Technical Specifications
HUSS Type Specifications
| Model No | Torque (Nm) | Switch Time (Sec/90) | Motor Power (W) | Insulation level | DC24V (A) | AC110V (A) | AC220V (A) | AC380V (A) | AC440V (A) | Weight (Kg) | Manual Device |
|---|---|---|---|---|---|---|---|---|---|---|---|
| HUS0S | 20 | 10 | 8 | E | 0.2 | / | / | / | / | 1.2 | Spanner |
| HUS1S | 35 | 12 | 10 | E | 1.2 | 0.4 | 0.3 | / | / | 2.8 | Spanner |
| HUS2S | 100 | 8 | 40 | F | 3 | 0.65 | 0.33 | 0.26 | 0.21 | 8 | Spanner |
| HUS2S | 200 | 8 | 60 | F | 4.2 | 0.89 | 0.45 | 0.27 | 0.21 | 8 | Spanner |
| HUS3S | 350 | 8 | 90 | F | 6.8 | 1.7 | 0.8 | 0.9 | 0.7 | 13 | Spanner |
| HUS3S | 500 | 8 | 120 | F | 8.5 | 2 | 1.1 | 0.9 | 0.7 | 13 | Spanner |
| Model No | Torque (Nm) | Switch Time (Sec/90) | Motor Power (W) | Insulation level | DC24V (A) | AC110V (A) | AC220V (A) | AC380V (A) | AC400V (A) | AC440V (A) | Weight (Kg) | Manual Device |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| HUS1H | 50 | 10 | 18 | F | 1.6 | 0.8 | 0.4 | 0.2 | / | / | 3.2 | Push hand Wheel Operation |
| HUS1H | 70 | 15 | 18 | F | 1.6 | 0.8 | 0.4 | 0.2 | / | / | 3.2 | Push hand Wheel Operation |
| HUS2H | 100 | 8 | 40 | F | 3.5 | 0.73 | 0.33 | 0.26 | 0.32 | 0.21 | 11 | Push hand Wheel Operation |
| HUS2H | 200 | 8 | 60 | F | 4.2 | 0.84 | 0.45 | 0.27 | 0.35 | 0.21 | 11 | Push hand Wheel Operation |
| Model No | Torque | Switch Time | Motor Power | Insulation level | Rated current(A) | Weight | Manual Device | |||||
| (Nm) | (Sec/90°) | (W) | DC24V | AC110V | AC220V | AC380V | AC400V | AC440V | (Kg) | |||
| HUS2 | 100 | 20 | 20 | F | 2.2 | 0.8 | 0.6 | 0.28 | / | 0.26 | 12 | Clutch‑less Hand Wheel |
| 200 | 30 | 20 | F | 2.3 | 0.8 | 0.6 | 0.28 | / | 0.26 | 12 | ||
| HUS3 | 300 | 20 | 40 | F | 3 | 1.6 | 0.85 | 0.39 | 0.31 | 0.47 | 14 | |
| 450 | 30 | 60 | F | 3.6 | 1.9 | 0.9 | 0.4 | 0.32 | 0.47 | 14 | ||
| HUS4 | 500 | 40 | 90 | F | 8.5 | 1.8 | 0.95 | 0.46 | 0.4 | 0.54 | 22 | |
| 800 | 48 | 90 | F | 8.5 | 1.8 | 0.95 | 0.48 | 0.41 | 0.54 | 22 | ||
| 1000 | 48 | 120 | F | 10.5 | 2 | 1.1 | 0.5 | 0.42 | 0.55 | 22 | ||
| HUS5 | 1500 | 35 | 200 | F | / | 4.8 | 2.8 | 1.2 | 0.9 | 1.1 | 43 | |
| 2300 | 48 | 200 | F | / | 4.8 | 2.8 | 1.2 | 0.93 | 1.1 | 43 | ||
| HUS5+G | 4000 | 81 | 200 | F | / | 4.8 | 2.8 | 1.2 | / | 1.5 | 78 | |
| 5000 | 94 | 200 | F | / | 4.8 | 2.8 | 1.2 | / | 1.5 | 78 | ||
*For all types: if Choose ICM Type, the weight will increase by an additional 5kg
Need Actuator Performance Data & Technical Datasheets?
Access motor load specs, wiring diagrams, torque curves, and factory test certificates to confirm compatibility with your valve product line.
Dimension
| HUS0S Quarter-turn Rotary Electric Actuator Dimensions | HUS1S Quarter-turn Rotary Electric Actuator Dimensions | HUS2S Quarter-turn Rotary Electric Actuator Dimensions |
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| HUS3S Quarter-turn Rotary Electric Actuator Dimensions | HUS1H Quarter-turn Rotary Electric Actuator Dimensions | HUS2H Quarter-turn Rotary Electric Actuator Dimensions |
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| HUS2 Quarter-turn Rotary Electric Actuator Dimensions | HUS3 Quarter-turn Rotary Electric Actuator Dimensions | HUS4 Quarter-turn Rotary Electric Actuator Dimensions F10-F12 |
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| HUS4 Quarter-turn Rotary Electric Actuator Dimensions F14 | HUS5 Quarter-turn Rotary Electric Actuator Dimensions | HUS5+G Quarter-turn Rotary Electric Actuator Dimensions |
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| HUS1S Intelligent Interation Quarter-turn Electric Actuator Dimensions | HUS2S Intelligent Interation Quarter-turn Electric Actuator Dimensions | HUS3S Intelligent Interation Quarter-turn Electric Actuator Dimensions |
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| HUS1H Intelligent Interation Quarter-turn Electric Actuator Dimensions | HUS2H Intelligent Interation Quarter-turn Electric Actuator Dimensions | HUS2 Intelligent Interation Dimensions |
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| HUS3 Intelligent Interation Quarter-turn Electric Actuator Dimensions | HUS4 Intelligent Interation Quarter-turn Electric Actuator Dimensions F10-F12 | HUS4 Intelligent Interation Quarter-turn Electric Actuator Dimensions F14 |
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| HUS5 Intelligent Interation Quarter-turn Electric Actuator Dimensions | HUS5+G Intelligent Interation Quarter-turn Electric Actuator Dimensions | |
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| HUS2H+Lifter Dimensional Drawing | HUS3+Lifter Dimensional Drawing | HUS4+Lifter Dimensional Drawing | ||
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| HUS2H+LT-1-30mm | HUS3+LT-1-30mm | HUS3+LT-2-60mm | HUS4+LT-2-60mm | HUS4+LT-3-100mm |
| HUS2H+ICM+Lifter Dimensional Drawing | HUS3+ICM+Lifter Dimensional Drawing | HUS4+ICM+Lifter Dimensional Drawing | HUS5+ICM+Lifter Dimensional Drawing |
 |  |  |  |
| HUS2H-ICM+LT-1 | HUS3-ICM+LT-2 | HUS4-ICM+LT-3 | HUS5-ICM+LT-3 |
Need Custom Drive Bushings or Extended High-Temperature Brackets?
Send us your valve stem dimensions (square, round-keyed, or flat-head) for custom drive inserts and mounting plate engineering.
HUS Quarter-Turn Series Purchase Guide
Sizing and selection guide for quarter-turn ball, butterfly, plug, and multi-port diversion valves.
Step 1: Rotation Angle & Travel | Step 2: Torque Calculation & Safety Factor |
| Standard Quarter-Turn (0°–90°): 2-way ball, butterfly, and plug valves. Extended Multi-Port Rotation:
| Actuator Torque = Valve Breakaway Torque × (1 + Safety Factor) Clean Water / Light Oils: Add 20% to 25% safety margin. Steam, Clean Gases & Compressed Air: Add 30% to 35% safety margin. Slurries, Viscous Media & High-Pressure Ball Valves: Add 40% to 50% safety margin. High Torque (>2,300 Nm): For large butterfly valves (DN300–DN600+) or high-pressure lines, pair the actuator with a worm gearbox for torque up to 5,000 Nm. |
Step 3: Mounting Interface & Fluid Temperature Brackets
| 1. ISO 5211 Direct Mounting | 2. Fluid Temperature & Bracket Selection |
| Flange Sizes: F05, F07, F10, F12, F14, F16 with double-square drive sockets. Custom Shafts: Custom drive bushings and brackets can be machined for round keyed shafts, square shafts, or special profiles (holes must be concentric with the outer circle). | Pipeline heat transfers to the actuator body during operation. Select mounting brackets based on fluid temperature:
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Step 4: Control Type & Ambient Temperature
| 1. Control Type | 2. Ambient Temperature Limits |
| Working Range:
Dehumidification Heater: When ambient temperature is below 0°C, install an internal dehumidification heater. |
Step 5: Power Supply & Options
| Power Supply Code (V) D: AC 220V (50/60 Hz) E: AC120 V (50/60 Hz) F: DC 24V G: DC 12V H: AC 380V (50/60 Hz) |  |
| Control method（K）： O :Open/Close M1 : 4 – 20 mA input/output M2 : 0 – 5V mA input/output M3 : 2 ‒ 10 V input/output ICM:Intelligent integrated control | |
| Enclosure & Options (B) Enclosure: Standard IP67 weatherproof; optional IP68 submersible. Dehumidification Heater (Option Code: H): Anti-condensation heating element (required when ambient temperature < 0°C). Fail-Safe Battery Pack (Option Code: B): Drives the valve to a preset Fail-Open or Fail-Close position during main power loss. | |
| Site Installation Notes Indoor Installation:
Outdoor Installation:
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*This information is for reference only, please consult our customer service for details.
Installation Suggestions
Indoor Installation:
For explosive gas atmospheres, order an explosion-proof model.
Specify in advance if installed in flooded pits or wet areas.
Reserve sufficient space for wiring, handwheel operation, and maintenance.
Outdoor Installation:
To protect against rain and direct sunlight, install a protective cover or choose IP67 or higher enclosure protection.
Reserve clearance for wiring, handwheel operation, and servicing.
Ready to Configure HUS Quarter-turn Rotary Electric Valve Actuator for Your Valve Packages?
Direct factory manufacturing with custom drive bushings, private labeling, and tested torque safety margins.
✓ ISO 5211 Direct Mounting
✓ OEM Private Labeling & Custom Colors
✓ Factory-Direct Wholesale Pricing
✓ OEM Private Labeling & Custom Colors
✓ Factory-Direct Wholesale Pricing
⚡ Technical verification and custom price sheets within 24 hours
FAQ About HUS Series Quarter-Turn Rotary Electric Valve Actuator (Convertible to Linear with Lifter)
Q1: Can HUS rotary electric valve actuators mount directly to standard valves without extra brackets?
Yes. HUS series quarter-turn electric actuator as an iso 5211 electric valve actuator matching standard F05 to F16 flange patterns and double-square sockets. If your valve top flange follows ISO 5211, our rotary electric valve actuator bolts straight on as an electric actuator for plug valve, ball, or butterfly valve assemblies. For non-standard valve stems, we provide custom drive inserts and adapter plates.
Q2: What is the risk of selecting an electric actuator without adding a media-specific safety factor?
Sizing an quarter-turn electric actuator purely based on the manufacturer’s dry catalog torque often leads to motor stalling during operational pressure surges, line scale buildup, or dry friction after long idle periods. Sizing with our recommended 20% to 50% margin ensures consistent breakaway thrust and extends internal gear life.
Q3: Can we calibrate HUS actuators without opening the cover in wet or dusty areas?
Yes, but only with the ICM smart model.
The ICM smart model lets you set open/close limits, running speed, and control settings directly from the outside using external control knobs or a handheld remote. This keeps the actuator housing fully closed and protected against water and dust (IP67/IP68).
The Modulating and On/Off models cannot be set up without opening the cover:
HUS Modulating models have a circuit board inside the housing with a 4-digit LED screen and four setting buttons. You must take off the top cover to adjust settings and set up the input signal.
HUS On/Off models use mechanical limit switches inside the housing, so you must also take off the cover to adjust the travel cams.
Q4: What happens if the command signal drops or power is cut on a HUS rotary electric actuator?
On Signal Loss: Configure the rotary electric actuator in the setup menu to Fail-Open, Fail-Close, or Fail-Hold (Stop).
On Power Loss: The self-locking worm gear mechanically locks the valve in its last position. For emergency fail-safe shutoff during blackouts, external battery backup packages are available.
Q5: Are HUS electric actuators suitable for outdoor, coastal, or high-humidity environments?
Yes. HUS quarter-turn electric actuator housings are manufactured from high-grade aluminum alloy treated with hard anodizing and exterior polyester powder coating, paired with 304/316 stainless steel fasteners for corrosion resistance. For high-humidity locations subject to day/night temperature swings, an optional internal space heater prevents condensation buildup in the electrical chamber.
Q6: Can you supply custom OEM branding and private labeling for valve manufacturers?
Yes. Operating as a dedicated quarter-turn actuator OEM supplier, we support full private labeling for valve OEMs and distributors, including custom laser-engraved nameplates, specific RAL paint finishes, and custom wiring configurations. Standard production orders ship within 15 to 25 days, with 100% torque, travel, and seal tests conducted prior to dispatch.
Q7: Can a HUS actuator switch between standard On/Off isolation and 4–20 mA continuous modulating in the field?
Only on HUS models with the ICM smart module, where you can change between On/Off and 4–20 mA modulating modes right in the LCD menu using the outer knobs or remote, with no need to open the cover. HUS models (On/Off or Modulating) use fixed internal hardware and cannot switch modes in the field, so you need to pick the exact control type when placing your order.
Q8: Does the HUS 3-phase electric actuator protect against wrong power wiring (L1/L2/L3)?
Only HUS 3-phase models with the ICM smart module have automatic phase correction, where the internal board checks incoming power lines and corrects rotation so the motor always runs the right way even if wires are mixed up during installation. Standard HUS On/Off and Modulating 3-phase models do not have this feature, meaning wrong phase wiring will make the motor run in reverse (opening instead of closing) until two power lines are manually swapped.
Q9: What is the fastest operating speed available for the HUS quarter-turn rotary electric valve actuator?
The HUS series offers high-speed models with 90° travel times of 1s, 2.5s, 3s, or 8s for applications that require fast valve opening and closing.
Q10: Is the HUS modulating actuator rated for continuous duty in heavy modulating loops?
Yes. HUS modulating actuators meet the EN 15714-2 Class D continuous modulating standard, rated for up to 1,800 starts per hour (S4/S5 heavy-duty cycle). The motor and drive gears run cool under high-frequency signal changes without thermal tripping.
HUS Series Quarter-Turn Rotary Electric Valve Actuator Technical Troubleshooting & Maintenance
| Symptom | Probable Cause | Action |
| Motor does not turn | 1. Lost phase or incorrect line voltage. 2. Motor thermal switch tripped. 3. Manual push-wheel engaged in manual position (for push-handwheel models). | • Check incoming terminal voltage against the nameplate. • Allow motor to cool down for auto-reset. • Release handwheel back to automatic mode. |
| Valve seat leaks at full close | 1. Close limit set too early. 2. Pipeline scale or debris caught in the seat. 3. Output torque or thrust is too low for line pressure. | • Re-adjust 0% close limit to ensure full seat contact. • Flush line to remove trapped debris. • Verify line differential pressure against actuator torque/thrust rating. |
| 4–20 mA feedback does not match position | 1. Potentiometer drive gear loose or out of line. 2. Zero / Span calibration shifted. | • Tighten feedback drive gear set screw. • Run auto setup in the Debug Menu to re-learn 0% and 100% limits. |
| Actuator oscillates around setpoint | 1. Electrical noise on control wiring. 2. Control deadband setting is too tight (<0.5%). | • Run shielded twisted-pair wire with ground grounded at one end only. • Increase deadband to 1.5%–2.0% in the setup menu. |
| LCD screen does not light up | 1. Blown internal power fuse.
2. Loose wiring terminal on power input. | • Check and replace the internal glass fuse. • Check and tighten incoming power wire terminal screws. |
[HEARKEN] VALVE AUTOMATION & OEM SUPPLY
