YOKOGAWA AXG1A Installation Manual page 38

Figure 4.4.4 Position of Protective Grounding Terminal
(Integral Type and AXW4A Remote
Transmitter)
Protective grounding terminals
Figure 4.4.5 Position of Protective Grounding Terminal
(AXG1A Remote Transmitter)
Protective grounding terminals
Figure 4.4.6 Position of Protective Grounding Terminal
(AXFA11 Remote Transmitter)
IMPORTANT
Improper grounding may result in an adverse effect
on the flow measurement. Ensure that the product is
properly grounded.
Protective
grounding
terminals
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<4. Wiring>
The electromotive force of the magnetic flowmeter
is minute and it is easily affected by noise, and the
reference electric potential is the same as that of the
measuring fluid. Therefore, the reference electric
potential (terminal potential) of the sensor and transmitter
also need to be the same as that of the measuring fluid.
Moreover, the potential must be the same as the ground.
The magnetic flowmeter is equipped with an grounding
ring that makes a connection with the charge of the
measured fluid for grounding and protects the lining.
Grounding rings are supplied with the products when
specified with dedicated optional code.
600 V vinyl-insulated cable
Cable cross section area:
2 mm 2 , and cross section
area larger than power cable
Grounding Resistance: 10 Ω or less (Class C requirements)
Note: When lightning protection performance by the built-in lightning
protectors is not required, grounding resistance 100 Ω or less
(Class D requirements) can be applied.
CAUTION
• The grounding should satisfy grounding resistance
requirement, 100 Ω or less (Class D grounding).
• For explosion protection type, the grounding must
satisfy the domestic electrical requirements as
regulated in each country.
In case grounding rings are not used.
In case grounding rings
(Available only for metal piping)
are used.
Figure 4.4.7 Grounding (Integral Flowmeter)
37
grounding ring
4
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IM 01E24A01-01EN