5 grounding, 6 power supply voltage and load resistance, Grounding – Yokogawa EJX115A User Manual
Page 36: Power supply voltage and load resistance
 
<5. Wiring>
34
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)
F0525.ai
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)
F0526.ai
Communication
applicable range
BRAIN and HART
R= E–10.5
0.0244
Figure 5.15 Relationship between Power Supply
Voltage and External Load Resistance