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Table 5-2: 12 VDC battery power supply system maximum cable lengths
Model
Min. batt
option
voltage
(V)
12 VDC
12.00
analyzer w/o
feed-through
heater
12 VDC
12.00
analyzer with
feed-through
heater
Note: This wire size may require splicing in 12 AWG or 2.5 mm
cable to be able to fit screw terminals.
5.2.3
Other considerations
When the same power supply is used to power other devices in addition to the analyzer:
Avoid any ground loops.
Connect all devices in a star configuration.
Determine the operating voltage range for the devices. Devices must be tolerant to input
voltage fluctuations within their acceptable range. Input voltage to these devices can be
affected by the length of the cable connecting to the power supply.
5.2.4
Ground the analyzer
The analyzer must always be properly grounded.
In the field:
The analyzer has a grounding lug on the mounting neck of the enclosure. This lug should
be tied to a good earth ground with no smaller than 12 AWG wire.
The analyzer cannot be connected to any pipeline where cathodic protection exists. If the
system uses cathodic protection, the analyzer must be mounted on a section of pipe that
has been electrically isolated from the cathodic currents (see
In an indoor environment (office/lab/processing plant, etc.):
For installations in an office environment, ensure that a good earth ground to the analyzer
is established. Improper grounding can lead to erratic behavior. If the device is not
properly grounded, the user could have as much as 60 VAC (half line voltage) on the case
of the equipment due to capacitive coupling within the power supply. Refer to the power
supply manufacturer for specific grounding requirements.
5.2.5
Cathodic protection
If the sample probe is mounted to a section of pipe where cathodic currents may exist, put isolators in
the sample tubing between the sample probe and the analyzer. Any time that the sample probe is on
a section of pipe other than the one where the analyzer is directly mounted, tubing isolators should be
employed. See
Figure
5-1. It is very important that the probe ground and the analyzer ground be at
the same potential. If this cannot be ensured, tubing isolators must be used.
5.2.6
Wire the analyzer power connector
The power connector is located on the analyzer termination board. It can be removed for wiring.
This procedure assumes that the optimal length of the wires between the analyzer and the power
supply is used as per section
To wire the power connector:
1.
Remove the modular connector from the POWER terminal (J1) on the analyzer's terminal board.
2.
Observing polarity carefully:
a.
Insert the wire from the power supply's positive pin to the analyzer's positive pin (+).
b.
Insert the wire from the power supply's negative pin to the analyzer's negative pin (-).
3.
Re-insert the modular connector on the POWER terminal (J1) if the power wires at the other
end are not yet connected to the power source. If the power wires are already connected to the
power source, you can wait to apply power to the analyzer for analyzer startup in section
Startup.
4 4 | N G C8 20 0 A N D PG C 10 0 0 US ER MA N UA L | 21 01 51 0MN A H
Unit 10
12
14
AWG
AWG
AWG
see note
ft
78.28
49.44
30.97
m
23.86
15.07
9.44
ft
38.74
24.47
15.32
m
11.81
7.46
4.67
5.2.2 Operating voltages and cable
16
6 mm
2
4 mm
AWG
see note
see note
19.43
90.03
60.17
5.92
27.44
18.34
9.62
44.55
29.78
2.93
13.58
9.08
2
or smaller wires at each end of the
Figure
lengths.
2
2.5 mm
2
1.5 mm
2
37.42
22.92
11.41
6.99
18.52
11.34
5.64
3.46
5-1).
6
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Troubleshooting
