In central Chiller air conditioning systems, precisely controlling the chilled water flow through the coils of Fan Coil Units (FCU) or AHUs is crucial to maintaining thermal comfort and optimizing energy efficiency. The device directly responsible for opening and closing the mechanical valve based on signals from the central controller is the Actuator. The Honeywell MT4-230-NC model is an industry-standard solution, perfectly fulfilling flow regulation requirements with exceptionally high reliability.

What is the Honeywell MT4-230-NC Actuator?

The MT4-230-NC model is a Small Linear Thermoelectric Actuator belonging to Honeywell's renowned MT4 series. This device utilizes a direct 230V AC power supply, which is common in Vietnam, and is designed in a Normally Closed (NC) configuration. It is typically coupled directly with small control valves like the V5832/V5833 via a standard adapter to perform mechanical open/close strokes.

Design Features and Key Advantages

Thermoelectric Principle: Unlike standard magnetic motors, the MT4-230-NC uses thermal expansion wax. When powered, the wax element heats up and expands, pushing the valve stem smoothly without generating mechanical noise (Silent operation).

Ultra-Compact Size: Suitable for installation in tight suspended ceiling spaces, right above the FCU condensate drain pan without causing structural interference.

Visual Position Indicator: Equipped with a red position indicator ring, allowing engineers to easily observe whether the valve is open or closed from a distance without measuring voltage.

Significance of Normally Closed (NC) Configuration

In Mechanical and Electrical (M&E) design, selecting a Normally Closed (NC) configuration serves as a fail-safe mechanism. In the event of a whole-building power outage or a severed signal cable, the internal compression spring mechanism automatically returns the valve stem to a fully closed position (0% flow).

Practical impact: This prevents 7°C chilled water from continuing to flood into the FCU coil while the blower fan has stopped. Without this feature, the air surrounding the coil would drop below the dew point, causing condensation, dripping water that damages plaster ceilings, and a loss of static pressure across the entire central water network.

Installation Guidelines and Technical Notes

Installation Position: Never install the Actuator pointing upside down. Correct installation involves the valve lying horizontally or the Actuator pointing straight up to prevent condensation from dripping back into the power circuit board.

Adapter: The included adapter ring must be used if installing on third-party valve bodies to ensure the standard 2.5 mm stroke maintains firm contact.

Technical Specifications :

Buy Genuine Honeywell Actuators at DLK

DLK TRADING SERVICES CO., LTD is proud to be an authorized distributor of Honeywell actuators and control valves in Vietnam. We commit to providing full CO/CQ documentation for origin verification, assisting M&E engineers in calculating pulling force, and selecting adapters perfectly compatible with project design drawings.

Contact DLK TRADING SERVICE CO., LTD: 070 357 0101 | info@dlk.com.vn | https://dlk.com.vn/