Rockwell Automation 900-TC32 Digital Temperature Controllers, Series B - Manual (Page 119)

Publication 900-UM007D-EN-E - January 2011
Configuration & Basic Operation 3-49
Figure 3.95 — CT Position for Single-Phase Heaters
Three-phase Heaters
When a 3-phase power supply is used, regardless of the types of connecting
lines, two current transformers (CTs) are required to detect heater burnout and
HS.
1. For Delta connecting power lines: Refer to the following diagram for
CT installation positions.
Note: Heater voltage fluctuations are not considered here. Take this into
account when setting the detection current.
Figure 3.96 — CT Installation Positions, Delta Connecting Power Lines
2. For Star (Y) connecting power lines: Refer to the following diagram
for CT installation positions.
Note: Heater voltage fluctuations are not considered here. Take this into
account when setting the detection current.
Figure 3.97 — CT Installation Positions, Start (Y) Connection Power Lines
CT
Load Load (such as a heater)
AC line
To controller
CT input
CT
Load
Load
To controller CT input
Load
Load (such as a heater)
AC line
AC line
To controller CT input
CT
CT
Load
Load
Load
Load (such as a heater)
AC line
To controller CT input
To controller CT input