Honeywell ML7425A, ML7420A SPECIFICATION DATA
ML7420 |
ML7425 |
GENERAL
The ML7420A / ML7425A,B actuators are designed for modulating control with controllers providing an analog output of 0...10 Vdc or 2...10 Vdc. They operate Honeywell’s standard valves in heating, district heating, ventilation, and air conditioning (HVAC) applications. Spring-return models provide a safety position at power failure.
® U.S. Registered Trademark
Copyright © 2007 Honeywell Inc. • All rights reserved
ML7420A/ML7425A,B
Electric Linear Valve Actuator
SPECIFICATION DATA
FEATURES
•Easy and quick installation
•No separate linkage required
•No adjustments required
•Low power consumption
•Force-limiting end stops
•Spring-return models (ML7425A,B)
•Manual operation knob
•Position feedback signal
•0...10 Vdc or 2...10 Vdc signal input selectable
•Direct / reverse action selectable
•Stroke position on signal failure selectable
•Corrosion-resistant design
•Maintenance-free
SPECIFICATIONS
Temperature Limits
Ambient operating limits |
-10...+50 °C at 5...95% r.h. |
Ambient storage limits |
-40...+70 °C at 5...95% r.h. |
Medium valve |
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temperature |
Max. 150 °C (220 °C with |
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High-Temperature kit) |
Signals |
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Signal input voltage |
y = 0...10 Vdc or 2...10 Vdc |
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Ri = 100kΩ |
Signal source |
1 kΩ max. |
Position feedback signal |
x = 2...10 Vdc |
Load |
1 mA max. |
Safety |
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Protection class |
III as per EN60730-1 |
Protection standard |
IP54 as per EN60529 |
Flame retardant housing |
V0 as per UL94 |
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(with metal cable gland) |
EN0B-0261GE51 R0707
ML7420A/ML7425A,B
Wiring |
1.5 mm2 |
Wiring terminals |
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Cable entry |
M20. Two additional knock- |
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outs M18 and M20 for |
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auxiliary switch and |
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potentiometer accessories |
Weight |
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non-spring return type |
1.3 kg |
spring return type |
2.4 kg |
Material |
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Cover |
ABS-FR |
Base |
glass fiber reinforced plastic |
Yoke |
aluminum diecast |
model number
supply voltage
power consumption
signal input 0(2) Vdc
signal input 10 Vdc
stroke
run time at 50 Hz
close-off force
spring return time
spring return direction
ML7420A6009 |
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ML7420A6017 |
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ML7425A6008 |
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ML7425B6007 |
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24 Vac ±15%; 50/60 Hz |
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5 VA |
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7 VA |
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12 VA |
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Actuator stem retracted. Two-way valve:”open”, three-way valve port A-AB:”closed” * |
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Actuator stem extended. Two-way valve:”closed”, three-way valve port A-AB:”open” * |
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20 mm |
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1 min |
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0.5 min |
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1.8 min |
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≥ 600 N |
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≈12 s |
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actuator stem extends |
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actuator stem retracts |
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at power failure |
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at power failure |
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* Factory setting; can be reversed by pressing the right-hand pushbutton (W3) located on the PCB (see Fig. 1).
OPERATION
General
The drive of a synchronous motor is converted into linear motion of the actuator stem via a spur gear transmission. The actuator stem is connected with the valve stem by a buttonkeyed retainer connection.
An integrated spring package limits the stem force to a factory-set value in either direction.
The actuator switches off precisely when the specified stem force is reached.
Manual Operation
Actuators without spring return are equipped with a manual operation knob used in case of power failure. Manual operation is permitted only after the power supply is switched off or disconnected.
To operate, push the manual operation knob down and turn clockwise to move the stem downward and counterclockwise to move the stem upward. If the actuator returns to automatic control, the manual operation knob unlocks automatically.
In the case of actuators with spring return, the manual operation knob is located under the cover.
Override Option
All actuators have an integrated override function (see also Fig. 3). When the override signal is applied, the actuator drives to the fully-open or fully-closed position, regardless of the controller signal.
Spring Return
The ML7425A,B spring return actuators provide a defined safety position of the valve in case of power failure.
The spring return actuators are shipped from the factory with a shipment stop (to lock the manual operation knob) in order to allow connection of the stem button retainer to the valve stem without power supply.
Electrical Installation
The actuators are delivered with a pre-installed cable gland M20 and two additional knock-outs for M18 and M20. Max. cable length/diameter for field mounting:
200 m / 1.5 mm2 or
100 m / 1.5 mm2 (ML7420A6017)
NOTE: To avoid malfunction, it is necessary to connect 24 Vac power and ground (see Fig. 3 on page 4).
Action
The direction of action can be reversed by pressing the lefthand pushbutton (W3) located on the printed circuit board (see Fig. 1), If the corresponding LED is lit, this indicates that the actuator stem will retract at a control signal of 0(2) Vdc (factory setting); if it is dark, the actuator stem will extend at a control signal of 0(2) Vdc.
Input Signal Range
The range of the analog input signal Y can be changed by pressing the right-hand pushbutton (W2) located on the printed circuit board (see Fig. 1). If the corresponding LED is lit, this indicates that the actuator is set for 0...10 V operation (factory setting); if it is dark, the actuator is set for 2...10 V operation.
EN0B-0261GE51 R0707 |
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