The ML7420A actuators are designed for modulating control with controllers providing an analog output of 2...10 Vdc. They operate Honeywell’s standard valves in heating, ventilation, and air conditioning (HVAC) applications.
FEATURES
• Easy and quick installation
• No separate linkage and adjustments required
• Low power consumption and maintenance-free
• Self-adaption function
• Force-limiting end stops
• Manual operation knob
• 0(2)~10 Vdc input and 2~10 Vdc position feedback signal
• Direct/ Reverse action adjustable
• Stroke position on signal failure selectable
• Corrosion-resistant design
SPECIFICATIONS
Temperature Limits
Ambient operating limits -10~+50 ℃ at 5~95% r.h.
Ambient storage limits -40...+70 °C at 5...95% r.h.
Medium temperature Max. 150 °C (220 °C with
High-Temperature kit)
Signals
Signal input voltage y=0~10 Vdc or 2~10 Vdc
Ri=100 KΩ
Signal
source 1 KΩ max.
Position feedback signal x=2~10Vdc(fully extended)
Load 1 mA max.
Safety
Protection class III as per EN60730-1
Protection standard IP54 as per EN60529
Flame retardant housing V0 as per UL94
(with metal cable gland)
Material
Cover ABS-FR
Base glass fiber reinforced plastic
Yoke aluminum diecast
Checking Faulty Confirmation
If they replace just the actuator, then, they may be a problem with the valve stem(if it doesn't go down, then it is jammed). Maybe they can test valve stem open and close first, pull up and pull down. Normal valve can just push down until the bottom. If stuck in the middle that will be stuck issues. Base on their video actuator cannot push down. Something wrong with valve.