Yokogawa ADMAG AXF - Manual (Page 39)

IM 01E20D01-01E 4-5
4. WIRING
For explosion proof type except TIIS, follow the
domestic electrical requirements as regulated in
each country.
IMPORTANT
When optional code A (lighting protector) is
selected, the ground should satisfy Class C
requirements (grounding resistance, 10
⍀ or less).
• The protective grounding terminals are located
on the inside and outside of the terminal area.
Either terminal may be used.
• Use 600 V vinyl insulation wires as the grounding
wires.
F0409.EPS
Protective grounding
terminals
Figure 4.1.8 Protective Grounding Terminal Location
IMPORTANT
Improper grounding can have an adverse effect
on the flow measurement. Ensure that the
instrument is properly grounded.
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 flowtube and
converter 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 connec-
tion with the charge of the measured fluid for ground-
ing and protects the lining. Be sure to ground the
flowmeter according to Figure 4.1.9.
F0410.EPS
600 V vinyl-insulated cable
(2 mm
2 or larger)
• Class D requirements (ground resistance,
100 ⍀ or less).
Optional code A (lighting protector): Class C
requirements (ground resistance, 10
⍀ or less).
• TIIS Flameproof type: Class C requirements
(ground resistance, 10 ⍀ or less) or class A
rquirements (ground resitance, 10 ⍀ or less).
• Explosion proof type except TIIS: Domestic
electrical requirements as regulated in each
country.
grounding ring
In case grounding rings
are used. In case grounding rings are
not used.
(Available only for metal piping)
Figure 4.1.9 Grounding
(6) Connecting to External Instruments
WARNING
Before wiring with external instruments, be sure
to turn off the magnetic flowmeter and any
external instruments.