Emerson Rosemount 700XA, Reference Manual

Page: 52 / 294

NOTICE
The grounding rod is not furnished.
Figure 4-4: Interior ground lug, lower enclosure
• Resistance between the copper-clad steel ground rod and the earth ground must not
exceed 25 Ohms.
• On ATEX-certified units, the external ground lug must be connected to the customer’s
protective ground system via 9 AWG (6 mm
2
) ground wire. After the connection is
made, apply a non-acidic grease to the surface of the external ground lug to prevent
corrosion.
• The equipment-grounding conductors used between the gas chromatograph (GC) and
the copper-clad steel ground rod must be sized according to your local regulations; the
following specifications apply in the US.
Length Wire
15 ft (4.57 m) or less 8 AWG, stranded, insulated copper
15 ft (4.57 m) to 30 ft (9.14 m) 6 AWG, stranded, insulated copper
30 ft (9.14 m) to 100 ft (30.48 m) 4 AWG, stranded, insulated copper
• All interior enclosure equipment-grounding conductors must be protected by metal
conduit.
• External equipment that is connected to the GC should be powered via isolation
transformers to minimize the ground loops caused by the internally shared safety and
chassis grounds.
• All process signal wiring should be of a single, continuous length between field devices
and the GC. If, however, the length of the conduit runs require that multiple wiring
pulls be made, the individual conductors must be interconnected with suitable
terminal blocks.
Installation and start-up Reference Manual
June 2022 2-3-9000-744
52 Emerson.com/Rosemount