<5. Wiring>
5-6
IM 01W03D01-01EN
One-to-one Connection
When connect the FN310 and HART device in one-
to-one, connect as Figure 5.11.
2-wire
1 2 3 4
HART
Device
+
–
F0511.ai
4-wire
(Active)
F0512.ai
1 2 3 4
HART
Device
+
–
External
Power
Source
+
–
25
0Ω
4-wire
(Passive)
F0513.ai
1 2 3 4
HART
Device
+
–
External
Power
Source
+
–
Figure 5.11
FN310 Input Terminal Wire Connection
Diagram
4-20 mA Loop Connection
When connect FN310 to the 4-20 mA loop, connect
as Figure 5.12.
2-wire
F0514.ai
–
+
+
–
Distributor
1 2 3 4
+
–
25
0Ω
HART
Device
4-wire
(Active)
F0515.ai
–
+
+
–
Distributor
1 2 3 4
+
–
External
Power
Source
25
0Ω
HART
Device
4-wire
(Passive)
F0516.ai
–
+
+
–
Distributor
1 2 3 4
+
–
External
Power
Source
25
0Ω
HART
Device
Figure 5.12 FN310 Input Terminal Wire Connection
Diagram to 4-20 mA Loop
In the 4-20 mA loop, use a 250 ohm resistor. When
connecting the FN310 away from HART device,
use a junction box. When connecting the FN310
directly, connect to 4-20 mA loop by using splice
connector.
CAUTION
• Remove the battery pack before wiring.
Refer to subsection 8.3 “Replacing the
Battery Pack” for the battery pack removing.
• When wiring to 4-20 mA loop, switch off the
power supplies of the 4-20 mA loop.
NOTE
Strip the insulated cover of the input cable inside
the FN310 so as not to interfere with the battery
pack.
Wiring to Ground Terminal
Protect the cable of the ground terminal by using
heat-shrink tubing, etc. Use a ring tongue terminal
for M4 terminals with an insulation sleeve.
