Flintec FT-111 - Step 4 B: Digital Load Cell Connection (Only FT-111 D)

FT-111, User Manual Rev. 2.0.0, June 2022 Page 20 of 137
Warning: Always connect Sense pins to Excitation pins for 4 wire connection. Non-connected sense pins may
cause the wrong Excitation voltage measurement and create an accuracy and instability problem.
Warning: Connect the load cell cable shield to the housing (recommended to increase the EMC immunity
against disturbances) or shield pin of the load cell connector.
Step 4b: Digital Load Cell Connection (Only FT-111 D)
The digital load cell wiring should be made carefully before energizing to avoid FT-111D and load cells from
damages. The instrument cable between the instrument, LPK24 Lightning protection kit and junction box
must be shielded and convenient for high speed RS485 interface. The wire diameter of the instrument cable
should be selected for maximum 0,5 volt drop between Junction box and LPK24 lightening protection kit.
Pin number (J2)
Definition
Description
1
A
+ RS485 for DLC interfacing
2
B
- RS485 for DLC interfacing
3
Gnd
Ground
4
P
in
Power input (from LPK24)
5
P
out
Power output (to load cells via LPK24)
6
PE
Protective Earth
Table 4.1
Imported Note:
Since the supply voltage of the digital load cell is isolated, its Ground (0 VDC) should NOT be connected to
another ground or PE-Protective Earth!!!
Figure 4.7 FT-111D, LPK24 and DLC connection with junction box
Figure 4.8 FT-111D, LPK24 and DLC connection without junction box