5 grounding, 6 power supply voltage and load resistance, Grounding – Yokogawa EJX115A User Manual
Page 36: Power supply voltage and load resistance
<5. Wiring>
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IM 01C25A01-01E
5.5 Grounding
Grounding is always required for the proper operation of
transmitters. Follow the domestic electrical requirements
as regulated in each country. For a transmitter with a
built-in lightning protector, grounding should satisfy
ground resistance of 10Ω or less.
Ground terminals are located on the inside and outside of
the terminal box. Either of these terminals may be used.
Ground terminal
(inside)
Ground terminal
(outside)
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SUPPL
Y
PULSE
CHECK
ALARM
Figure 5.14 Ground Terminals
5.6 Power Supply Voltage and
Load Resistance
When configuring the loop, make sure that the external
load resistance is within the range in the figure below.
(Note) In case of an intrinsically safe transmitter, external load
resistance includes safety barrier resistance.
600
250
0
10.5 16.6
25.2
42
External
load
resistance
R (Ω)
Power supply voltage E (V DC)
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Communication
applicable range
BRAIN and HART
R= E–10.5
0.0244
Figure 5.15 Relationship between Power Supply
Voltage and External Load Resistance