Generac Power Systems CorePower Repair Manual page 49

TRANSFER SWITCH
3. Set a VOM to measure AC voltage.
4. Connect one meter test lead to Wire N1 at the incoming
Utility sensing connector. Connect the other meter test
lead to Wire N2. Approximately 240 VAC should be
measured.
Results
1. If voltage was measured in Step 4 and the pin
connections are good, replace the circuit board.
2. If voltage was NOT measured in Step 4, repair or replace
Wire N1/N2 between connector and terminal block.
PART 3
Section 3.4
Diagnostic Tests
Page 47