RTHD and RTAC - Trane

Over/Under Voltage
Starter Module 1 Switch the line power off and run a separate 120 VAC control power to the
chiller controls. With the controls powered up (Chiller mode set to Stop),
measure the common mode input voltages to the Starter module as VDC and
verify they fall within the following:
Table 7. Starter Module Potential Transformer Input DC Voltages
Starter Module Input Minimum Acceptable DC Maximum Acceptable DC
Terminals
Voltage(VDC)
Voltage(VDC)
J5-1 with respect to ground +2.45 +2.55
J5-2 with respect to ground +2.45 +2.55
J5-3 with respect to ground +2.45 +2.55
J5-4 with respect to ground +2.45 +2.55
J5-5 with respect to ground +2.45 +2.55
J5-6 with respect to ground +2.45 +2.55
2 If any of the voltages are not within the acceptable range listed in Appendix A
Table 2, then disconnect all the external wires to the J5-1 to 6 terminals. Again
measure the voltages in Table 7..
If the voltages all fall within the acceptable range, then there is most likely an
error in the external wiring to the Starter module potential transformer inputs.
This includes the potential transformers themselves.
If any voltage is not within the acceptable range, then there is most likely a
problem with installation of the Starter module or with the Starter module
itself. Check the four wire LLIDs bus connection to the Starter module. Check
the 24 +/- 2.4 VDC power supply input. Insure the Starter module is grounded
via the mounting screws. If installation is correct, replace the Starter module.
RLC-SVD05A-EN 33