Generac Power Systems PWRcell Reference Manual page 61

Transferring to Standby – Generator Only Configuration
12 VDC is delivered to the transfer relay through Wire 194 and back to the controller through Wire 23. When the five
second engine warm-up timer expires, the controller will take Wire 23 to ground which will energize the Transfer Relay.
The N.O. and N.C. relay contacts will change states. This will connect generator voltage from E1 through wire 205 at
relay connector 6 to E2A relay connector 4. The voltage will go through the N.C contact of XB1. Voltage from both E1
and E2 will be available at the C2 coil. This voltage will pass through the rectifier in the coil and the coil will energize.
Generator voltage is now delivered to the standby closing coil (C2), via generator voltage E1 and E2, the now closed
relay contacts, Wire 205, the limit switch (XB1), Wire B, and a bridge rectifier. The standby closing coil energizes and
the main current carrying contacts of the transfer switch are actuated to the "Standby" position.
•
As the main contacts move toward the "Standby" position, limit switch XA1 closes (Utility Coil). When the
contacts are in the "Standby" position, a mechanical interlock actuates XB1 to its open position. When XB1
opens the C2 coil de-energizes.
•
Generator voltage is now available to the LOAD terminals (T1 and T2) of the transfer switch and 120 VAC is also
supplied to the controller on Wire T1 for the battery charger. (220 VAC on T1 and T2 50 Hz only.)
NOTE: This is an example of Transfer Switch Operational Analysis. For troubleshooting use the operational analysis
with the appropriate wiring/schematic diagrams. XA1 and XB1
Diagnostic Repair Manual
Figure 8-16. Transferring to Standby
Section 8 PWRcell ATS
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