Gas Chromatograph Wiring - Emerson Rosemount 700XA Reference Manual

Reference Manual
2-3-9000-744
4.3

Gas chromatograph wiring

4.3.1 Wiring precautions
• All wiring, as well as circuit breaker or power disconnect switch locations, must
conform to the CEC or NEC; all local, state, or other jurisdictions; and company
standards and practices.
• Provide single-phase, three-wire power at 115 or 220 Vac, 50-60 Hz.
NOTICE
If you do not have a single phase, three-wire AC power source, you must purchase an
isolation transformer.
• Locate a power shut-off or disconnect switch in a safe area.
• Provide the gas chromatograph (GC) and any optionally installed devices with one 20-
amp circuit breaker for protection.
NOTICE
15 amps is the maximum current for 14 American Wire Gauge (AWG).
• Ensure that the 24 Vdc input power is compliant with the separated extra-low voltage
(SELV) standard by suitable electrical separation from other circuits.
• Use multi-stranded copper conductor wire according to the following
recommendations:
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4.3.2 Signal wiring
Follow these general precautions for field wiring digital and analog input/output (I/O)
lines:
• For shielded signal conducting cables, shield-drain wires must not be more than two
American Wire Gauge (AWG) sizes smaller than the conductors for the cable. Shielding
is grounded at only one end.
• Metal conduit or cable (according to local code) used for process signal wiring must be
grounded at conduit support points, because intermittent grounding helps prevent the
induction of magnetic loops between the conduit and cable shielding.
• A single-point ground must be connected to a copper-clad, 10 ft (3.05 m) long, 0.75 in
(19.0 mm) diameter steel rod, which is buried, full-length, vertically into the soil as
close to the equipment as is practical.
Rosemount 700XA
For power feed distances up to 250 ft (76 m), use 14 AWG (18 metric wire gauge
[MWG]), stranded.
For power feed distances 250 ft (76 m) to 500 ft (152 m), use 12 AWG (25 MWG),
stranded.
For power feed distances 500 ft (152 m) to 1,000 ft (305 m), use 10 AWG (30
MWG), stranded.
Installation and start-up
June 2022
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