Flowserve MX Electronic Actuator SIL Safety IOM - Manual (Page 6)

Limitorque MX Electronic Actuator FCD LMENIM2350-01 – 9/13
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FLOWSERVE PROPRIETARY INFORMATION
Use or disclosure of this information is subject to the restrictions on the title page of this document
1.1 System Overview
The MXa Electronic Actuator is a smart, double-sealed, multi-turn actuator that employs an absolute encoder for
position and speed feedback.
The MXA motor is designed for high starting torque and low inertia to reduce valve position overshoot. If motor
maintenance is required, it may be removed from the actuator while the actuator’s oil lubricated gear case remains
sealed. The LimiGard™ feature (US patent #5,719,559) continually monitors the motor contactor, control relays,
internal logic circuits, and external command signals to detect possible malfunctions, while warning the user that
the actuator should be examined and repaired. Coupling the LimiGard features with built-in Partial Stroke testing
capability provides users with strong assurance that the Limitorque actuator will be ready for action when called
upon by its configured Safety Instrumented Function.
The double-sealed design provides a termination chamber that is separated and moisture sealed from the control
compartment. The terminal compartment contains provisions for connecting power, earth, and control wiring. Wiring
may be connected without opening the controls compartment, thus protecting the internal controls from exposure to
potentially damaging environmental factors.
The hand wheel provides backup for manual operation. When the declutch lever is placed in its manual operation
position, the output drive is coupled to the hand wheel and the valve position may be changed with it. The actuator
automatically returns to motor operation whenever the motor is energized.
The housing is cast aluminum with a powder-coating that is suitable for many harsh environments.
The following documents form a part of this document to the extent specified herein. Unless otherwise specified, the
issues of documents are those cited in the solicitation or contract.
For further details, refer to Instruction, Operation & Maintenance [IOM] manual for Limitorque MX Electronic Actuator,
LMENIM2306. The latest version may be found on the Flowserve web site at www.flowserve.com.
No. Description
1 Motor cover
2 Motor rotor
3 Wiring harness with plug-in connectors
4 Clutch ring on drive sleeve
5 Terminal block
6 Worm/worm gear set
7 Baseplate
8 Printed circuit board – power
9 Local control and configuration knobs
10 Liquid crystal display [LCD]
11 Absolute position encoder
12 Controls compartment
13 Motor declutch lever
14 Handwheel (manual override)
1
2
3
4
5 6 7 8 9
10
11
12
13
14
Figure 1.1 – MXa Electronic Actuator