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Manual
MS-00809-0100-0470
Table 3-5
a 24 Vdc supply at the maximum power draw (55 W) while the analytical oven heats up
during start-up.
Table 3-5: American wire gauge (AWG)
Resistance per 1000 feet (in
ohms)
Voltage drop per 1000 feet at
2.5 A (in Vdc)
Maximum length (3 Vdc
power drop) in feet
Table 3-6: Metric wire size
Resistance per 100 m (in Ohms)
Voltage drop at 100 m at 2.5 A (in Vdc)
Maximum length (3 Vdc power drop) in
meters
3.14.2
Grounding precautions
Follow these general precautions for grounding electrical and signal lines:
NOTICE
Ground the gas chromatograph (GC) through the ground terminal on the left hand lower
side of the lower housing.
•
Metal conduit used for process signal wiring must be grounded at conduit support
points (intermittent grounding of conduit helps prevent induction of magnetic loops
between the conduit and cable shielding).
•
A single-point ground must be connected to a copper-clad, 10-ft. long, ¾-in. diameter (3
m long, 19.1 mm diameter) steel rod, which is buried, full-length, vertically into the soil
as close to the equipment as is practical.
NOTICE
The grounding rod is not furnished.
•
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
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.
Rosemount 470XA
and
Table 3-6
estimate the voltage drop and the maximum length of cable with
12
1.62
4.05
740
2.5
1.3
3.25
92
14
2.58
6.44
465
1.5
2.1
5.25
57
2
) ground wire. After the connection is
Installation
June 2023
16
4.08
10.21
293
55
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