Grounding; Power Supply Voltage And Load Resistance - YOKOGAWA EJX110A Installation Manual

5.4.3 Cable Connection RTD Terminal Box
Side
EJX multivariable transmitter RTD I/F is for 3-wire Type
RTD, Pt100.
Heed the following when wiring an RTD of the 2- or 4-wire
type.
NOTE
Please note that a temperature error will occur when
you use a 2-wire RTD because of wiring resistance.
Please do not ground the shield on the RTD side of
the cable.
CAUTION
Please use only the cables provided with this
instrument.
When wiring, be sure not to damage the cable's
insulation or its core.
All the cable cores must have sufficient insulation
around them.
Do not let the signal line contact the shield line.
Do not allow the shield line or the signal line to come
the earth potential voltage.
2-Wire 3-Wire
A
B A
Figure 5.18 The Method of Wiring for the RTD Side
Table 5.2 The Method of Wiring for the RTD Side
RTD Terminal
RTD Terminal A a
2-Wire White -
3-Wire White -
4-Wire White open
NOTE
The color display in the table shows the white line of
the cable.
The cable color could change depending on the cable
type.
Blue 1 and blue 2 allow changing places.
For 2-wire Type, connect either which is blue1 or
blue2, and give other side as OPEN.
4-Wire
a B b
B b A
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B b
Blue1 and Blue2 -
Blue1 Blue2
Blue1 Blue2
<5. Wiring>
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)
Figure 5.19 Ground Terminals
5.6 Power Supply Voltage and
Load Resistance
For 4 to 20 mA output only.
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
E–10.5
External
R=
0.0244
load
resistance
R (Ω)
250
0 10.5 16.6
Power supply voltage E (V DC)
Figure 5.20 Relationship between Power Supply
Voltage and External Load Resistance
47
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Communication
applicable range
BRAIN and HART
25.2 42
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IM 01C25A01-01E