Instruction manual

20 RFT9739 Field-Mount Transmitter Instruction Manual
Power-Supply and Sensor Wiring
continued
Figure 4-4a. Grounding detail — typical
Figure 4-4b. Grounding detail — European installations
I.S. ground
terminals
Internal
case ground
terminal
Earth ground
Power ground
terminal
If national standards are not in effect, adhere to
these guidelines for grounding:
• Use copper wire, 14 AWG (2.5 mm²) or larger
wire size.
• Keep all ground leads as short as possible, less
than 1 ohm impedance.
• Connect I.S. ground terminals directly to internal
case ground terminal.
• Connect ground lead from power ground terminal
directly to earth ground.
• Follow plant standards, instead of this standard, if
a separate high-integrity intrinsically safe ground
scheme is used.
I.S. ground
terminals
Internal
case ground
terminal
Earth ground
Power ground
terminal
If national standards are not in effect, adhere to
these guidelines for grounding:
• Use copper wire, 14 AWG (2.5 mm²) or larger
wire size.
• Keep all ground leads as short as possible, less
than 1 ohm impedance.
• A factory-installed ground wire, connecting the
I.S. ground and internal case-ground terminals,
must remain in place.
• Connect ground lead from power ground terminal
directly to earth ground.
• Follow plant standards, instead of this standard, if
a separate high-integrity intrinsically safe ground
scheme is used.
• To achieve potential equalization and comply with
CENELEC standards for hazardous area
installations in Europe, connect the external
ground terminal to the appropriate ground
terminals within the hazardous area, using a
potential equalizing line.
• For hazardous area installation in Europe, use
standard EN 60079-14 as a guideline.
External ground
terminal