VEVOR Manual Transfer Switch, 30-Amp 6-Circuit, Prewired Generator Transfer Switch Kit with NEMA L14-30P Power Inlet Box, Double-Throw Switch, NEMA 3R, Mechanical Watt Meter, for 7500W Generators
Dear Customer, Thanks for your inquiry.
The wire diameter of the 15a circuit is 2.5mm²=13awg, the wire diameter of the 20a circuit is 4mm²=11awg, and the wire length connected to the main distribution box is 130cm.
I have 4 circuits with 20 amps Breakers.and 2 with 15 amps. Can I change 15's to 20's Or connect 20 amp circuits to the 15 amp breakers in the transfer box?
We recommend checking if the load on the 20A line in the distribution box is lower than 15A. If so, you can directly connect the transfer switch. Changing the transfer switch to a 15A line would require replacing the cables and mini circuit breaker, which would be very troublesome.