Guardian 4389 Diagnostic Repair Manual page 58

SECTION 3.2
V-TYPE PREPACKAGED
PART 3
TRANSFER SWITCHES
OPERATIONAL ANALYSIS
UTILITY RESTORED, RETRANSFER BACK TO UTILITY
As the utility coil pulls the transfer switch to an OVER CENTER position, the switch mechanically snaps to
UTILITY. On closure of the main contacts to the utility power source side, Limit Switches XA1 and XB1 are
mechanically actuated to arm the circuit for transfer to STANDBY.
Figure 8. Utility Restored, Retransfer Back to Utility.
Page 3.2-8