Yokogawa ADMAG AXW - Manual (Page 24)

<4. WIRING>
4-5
IM 01E25D11-01EN
(3) Wiring the Remote Flowtube with AXFA11
Converters
Connect wiring as shown in the figure below.
I+
4-20mA out
Shortbar
I–
CURRENT OUT
AL+ AL– C SA A B SB
ALARM OUT
N/– L/+
POWER SUPPLY
EX2 EX1
EXCIT ATION
P– SI1+ SI2+ COM P+
PULSE OUT STATUS IN
SIGNAL
SO1+ COM SO2+
STATUS OUT
FUSE
2.5A 250V
AXFA11 converter
Converter
Remote
flowtube
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SA
A
B
SB
C
EX1
EX2
Taping*
A
B
Taping*
C
EX1
EX2
* Individually tape and insulate
the shields corresponding to
SA and SB on the remote
flowtube side.
Remote flowtube
EX2
Excitation
cable
EX1
A
B
C
AXFC dedicated
signal cable
Figure 4.1.9 Wiring Diagram
(4) Grounding
CAUTION
Be sure to connect the protective grounding of
the remote flowtube with a cable of 2 mm 2 or
larger cross section in order to avoid electrical
shock to the operators and maintenance
engineers and to prevent the influence of
external noise.
Connect the grounding wire to the mark.
The grounding should satisfy Class D
requirements (ground resistance, 100 Ω or less).
IMPORTANT
Improper grounding can have an adverse affect
on the flow measurement. Ensure that the
instrument is properly grounded.
The electromotive force of the magnetic flowmeter
is minute and it is easy to be affected by noise. And
also that reference electric potential is the same
as the measuring fluid potential. Therefore, the
reference electric potential (terminal potential) of
the flowtube and the converter also need to be the
same as the measuring fluid. Moreover, that the
potential must be the same with ground.
Be sure to ground according to Figure 4.1.10.
Refer to Figure 3.3.5 or 3.3.6 for wiring to the
flanges of remote flowtube when optional grounding
rings are not used.
• Class D requirements (ground resistance.
100 Ω or less).
600 V vinyl insulated
electric cable
(2 mm 2 or larger)
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With optional grounding
rings.
Without optional grounding rings.
(Available only for metal piping)
Figure 4.1.10 Protective Grounding Terminal Location
(5) Installing the Cover
Install the cover to the flowtube by turning it in the
direction of the arrow as shown below. Tighten
the cover locking screw counterclockwise using a
hexagonal wrench (nominal size 3 mm) to lock the
cover.
F0411.ai
Figure 4.1.11 Installing the Terminal Box Cover