220 VOLT GENERATOR GENERATOR

This means a neutral that was sized for 15 amps, but has 30 amps flowing through it, may start a fire inside the house walls. For safety reasons, neutrals do not have over-current protection (circuit breakers or fuses). This could put 30 amps through a neutral that is sized for 15 amps. This is bad because it is possible to have 15 amp (from black wire) plus 15 amp (from red wire) flowing through the same shared neutral. However, if you connect the same single phase 120 VAC to both phases in your homes circuit breaker box, then any circuits that share a neutral will NOT have opposite phases, and the current will not cancel out.

This means that a 15 amp load from black to neutral, and a 15 amp load from red to neutral, will have near 0 amps flowing on the shared neutral. This means that the current from the black wire when it gets to the neutral, will cancel the current from the red wire, when it gets to the neutral, as long as the two wires (black and red) are on opposite phases.

The reason there is 240 Vac in the black to red measurement, is that the voltage in the black wire is opposite phase compared to the red wire. In this case the black and red wire share one white neutral wire. The black wire with respect to the red wire will show 240VAC. The red wire will also measure 120VAC with respect to neutral. The black wire will measure 120VAC with respect to neutral.

Sometimes electricians will use a 3 wire, plus ground, romex cable with a black, red and white wire inside a single overall plastic jacket to supply power to several 120VAC loads. This means that if you have two circuit breakers directly next to each other vertically, and if you use a volt meter to measure the voltage across them (please be very careful) you will measure 240 VAC. Most house circuit breaker panels are setup for 240Vac made of two opposite phases of 120Vac.

220 VOLT GENERATOR GENERATOR

Here is the reason I recommended not connecting the same single phase 120VAC from your generator to both phases (L1 and L2) of your house's circuit breaker panel.

220 volt generator