44 Field Wiring Chapter 2
Reference Temperature Sensing with the VT1422A

The Screw Terminal and Spring Terminal Modules provide an on-board thermistor

for sensing isothermal reference temperature of the terminal blocks. Also provided

is a jumper set (J1 in Figures 2-7 and 2-8) to route the VT1422A's on-board current

source to a thermistor or RTD on a remote isothermal reference block. Figure 2-7

and Figure 2-8 show connections for both local and remote sensing. See “Connecting

the On-Board Thermistor” on page49 for location of J1.

VT1422A
Terminal Module Field Wiring
On-Board
Current Source
REM ON
BOARD
J1
HTI
LTI
HTS
LTS
Hnn
Lnn
Any Sense
Channel
Figure 2-7. On-Board Thermistor Connection
VT1422A

Terminal Module Field Wiring

On-Board
Current Source
REM ON
BOARD
J1
HTI
LTI
HTS
LTS
Hnn
Lnn
Any Sense
Channel
Figure 2-8. Remote Thermistor or RTD Connections