Flowserve MX FOUNDATION Fieldbus Field Unit - Manual (Page 17)

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MX/QX FOUNdaTION Fieldbus Field Unit FCd LMENIM2330-01 – 08/11
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2. Prepare the cable and label all wires. See Section 2.6.2.
3. Install power and control wires in separate conduits.
4. Install and verify earth grounds. The cable shields should be tied together. Ground the fieldbus
shield only at one point. The MX/QX FF unit should not connect either conductor of the cable to
ground at any point in the network. Refer to Section 2.4 - Cable Grounding.
NOTE: Limitorque defines an effective local earth ground as a low impedance (less than 5 ohms) path
to either:
• A ground electrode placed in the close vicinity of the actuator, which is free of ground loop
currents. OR
• A safety ground that is free of ground loop currents running from the actuator back to the system
ground electrode. If the signal wiring is run on aerial cable where it may be exposed to high energy
electrostatic discharge (such as lightning), a low impedance path to ground which is capable of
high current must be provided a short distance from the actuator as described above. OR
• A power distribution grid identifying the impact of power isolation to a particular actuator or group
of actuators should be provided.
2.6.2 Network Cable Preparation
Care must be taken during cable preparation:
• When stripping the insulation, use wire strippers that do not nick the wire.
• Use crimp ferrules to prevent stranded wires from getting loose and shorting to other wires.
• Use vibration resistant wiring terminals that hold the ferrule securely.
2.6.2.1 Network Cable Connection to the MX/QX FF Unit
The field device is connected to the network through the MX/QX terminal block. The network cable is
connected to terminal block as shown in Figure 2.8.
NOTE: The MX/QX FF device is sensitive to polarity. The cables should indicate polarity and polarity
should be maintained through all connection points.
Figure 2.8 – Network Cable Connections to Terminal Blocks
Network data-FF1(-)
Network data-FF1(+)
Network data-FF1(-)
Network data-FF1(+)
Terminal block
3
4
5
14
13
A
B