Emerson Micro Motion MVD Direct Connect, Installation Manual

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Installation Manual 25
Installation
3.10 Grounding
The sensor/core processor assembly (see Figure 2-1 and Figure 2-3 ) or the sensor alone (see
Figure 2-2 and Figure 2-4 ) must be grounded. To ground these components, see the sensor
installation manual.
If your installation includes a remote core processor (see
Figure 2-2 and Figure 2-4 ), it must
be grounded. To ground the remote core processor:
• The core processor has two internal ground screws: one 4-wire ground screw and one
9-wire ground screw. Do not use the 4-wire ground screw. The 9-wire ground screw
may be used (see
Figure 3-13 ). To access the 9-wire ground screw, remove the core
processor end-cap (see Figure 3-2 ).
• Use copper wire, 14 AWG (2,0 mm 2 ) or larger, for grounding.
• Keep all ground leads as short as possible, less than 1 ohm impedance.
• Connect ground leads directly to earth, or follow plant standards.
If your installation includes the MVD Direct Connect I.S. barrier (see Figure 2-3 and Figure
2-4 ), the barrier is not grounded. Do not ground the barrier.
Figure 3-13 Core processor 9-wire ground screw
Note
This step is required for all MVD Direct Connect installations.
CAUTION!
Improper grounding could cause measurement error. To reduce the risk of measurement
error:
• Ground the meter to earth, or follow ground network requirements for the facility.
• For installation in an area that requires intrinsic safety, refer to the appropriate Micro
Motion approval documentation.
• For hazardous area installations in Europe, refer to standard EN 60079-14 if national
standards do not apply.
9-wire ground screw