Generac Power Systems OG 2697 - Manual (Page 13)

When three-conductor wiring is used, two
0 volt circuits will often share the same neutral
wire. To avoid overloading the neutral, you
should either move BOTH of the circuits that
share the neutral or don’t move either of them.
When moving two circuits with a shared
neutral, they should be connected to adjacent
positions (one above the other) in the transfer
switch. That will assure that the two hot wires
are on separate phases and will maintain their
relationship to neutral.
Select a circuit you want to back up and
remove the power lead from the breaker.
Using UL Listed wire nuts, reconnect the
power lead to a matching breaker in the
transfer switch.
Make sure each circuit you move is protected
by the same size breaker in the transfer switch.
5 Amp circuits must be connected to 5 Amp
breakers and 0 Amp circuits to 0 Amp breakers.
For every circuit you move to the transfer
switch, connect the white neutral wire to the
neutral bar in the distribution panel.