Wiring Of The Thermocouple Type J; Caution Regarding Wiring; Grounding - Mitsubishi Electric FX3G User Manual

FX /FX /FX /FX /FX
3S 3G 3GC 3U 3UC
FX -4AD-TC-ADP (4-channel Thermocouple Data Input)
3U
3.5.2

Wiring of the thermocouple type J

*1. To use a J thermocouple type, be sure to connect the thermocouple to these terminals. In addition,
select J type by turning on the type K/J selection special auxiliary relay.
*2. Keep the thermocouple away from inductive noise (commercial power, etc.).
*3. For FX /FX
3S
available.
3.6

Caution Regarding Wiring

• It is not possible to connect different types of thermocouples to 4 channels of TC-ADP. Be sure to use the
same type of thermocouple for all the channels.
• TC-ADP is not insulated between the channels. For this reason, be sure to use a non-grounded type
thermocouple.
• Be sure not to connect to the terminal "•".
3.7

Grounding

Grounding should be performed as stated below.
• The grounding resistance should be 100 Ω or less.
• Independent grounding should be performed for best results.
When independent grounding is not performed, perform "shared grounding" as shown in the following
figure.
Other
PLC
equipment
Independent grounding
Best condition
• The grounding wire size should be AWG22 to 20 (0.3 to 0.5 mm
• The grounding point should be close to the PLC, and all grounding wires should be as short as possible.
PLC User's Manual - Analog Control Edition
Terminal block
*1
Thermocouple Compensating
type J *2 lead wire
Shield
*3
24V DC
Class-D
grounding
L+, L-, ch: represents the channel number.
/FX Series PLC (AC power type), the 24 V DC service power supply is also
3G 3U
→ For details, refer to the User's Manual - Hardware Edition of the each PLC Series.
Other
PLC
equipment
Shared grounding
Good condition
TC-ADP
type J
Temperature
type J
compensating circuit
3k
ch
L+
L-
Temperature
compensating circuit
3k
ch
L+
L-
+5V
24+
24-
Other
PLC
equipment
Common grounding
Not allowed
2
).
3 Wiring
3.6 Caution Regarding Wiring
L-17
K
L
M