Operation; Automatic / Manual Mode - ABB Contrac LME620-AI Operating Instruction

5

Operation

5.1

Automatic / manual mode

The servo motor triggered by the power electronics controls the axially fixed drive sleeve/nut
assembly via grease-lubricated spur gears. A ball bearing screw (see Figure Fig. 12) radially
fixed by an anti-twist arrester converts the rotary motion to a linear one.
A position sensor detects the current thrust rod position via mechanical reduction gearing
without backlash.
The motor brake locks the actuator in the current position if the power supply is cut off.
Fig. 12: Ball bearing screw with nut, cross-section
Manual mode allows you to move the actuator manually when the electrical power is off.
Caution - Risk of injury!
When pressing the hand wheel lock, restoring force from the valve may be present in the hand
wheel.
To prevent the hand wheel from turning unintentionally, hold the hand wheel with one hand.
1.
Important
Turning the hand wheel to the right causes the thrust rod to extend.
2.
3.
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Press the hand wheel lock.
Turn the hand wheel to move the part-turn actuator to the desired position.
Release the lock.
LME620-AI/-AN (Contrac)
Operation
M00308
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