Generac Power Systems PWRcell Reference Manual page 64

Section 8 PWRcell ATS
Utility Restored, Transferring Back to Utility – Generator Only Configuration
After the 15 second return to utility delay expires, the controller will open the Wire 23 circuit from ground. The transfer
relay de-energizes, the N.O. and N.C. contacts change state. Utility voltage is delivered to the utility closing coil (C1)
through Wires N1A and N2A, the normally closed contacts containing Wires N1A and 126, and limit switch (XA1). With
utility voltage applied to both sides of the utility closing coil (C1), the rectifier in the coil causes the coil to energize.
When the relay de-energizes its utility side contacts close, utility voltage is delivered to the utility closing coil (C1), via
utility voltage from N1A and N2A, the closed relay contacts, Wire 126, limit switch (XA1), and a bridge rectifier.
•
The C1 coil energizes and moves the main contacts to their "Utility" Position; the LOAD terminals are now
powered by Utility.
•
Movement of the main contacts to the "Utility" position actuates the limit switches. XA1 opens and XB1 closes on
the Standby source side.
NOTE: This is an example of Transfer Switch Operational Analysis. For troubleshooting use the operational analysis
with the appropriate wiring/schematic diagrams.
60
Figure 8-19. Utility Restored, Transferring Back to Utility
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Diagnostic Repair Manual