some transformers unite the primary and secondary and they are not isolation transformers but autotransformers. all the energy is being conducted through the transformer core by induction not by electrical connection. this can be a technique of providing safety, so if you got yourself involved with the secondary windings you may feel a shock but the number of amps that can be delivered may be limited by the physical size, number of windings etc. this isolation means the pimary and secondary are separated and the power of the secondary is limited to what the transformer can transfer. you can verify that with a meter and you should see no connections between the primary and secondary windings. some transformers ( autotransformers) are not isolated. The transformer shows two windings so it appears that the incoming current and the outgoing current from the transformer are not electrically connected. The previous poster was right the ground shouldn't be a part of the circuit.

I believe the line that is drawn between the two switches indicates a mechanical link. The schematic seems a bit weird because at the top it shows two switches and they are united. In 110 volt AC wiring you may actually follow that white back into the inners of the panel and find it is grounded, however that white wire may have potential as it is a part of the electrical circuit. Usually any machine is grounded and if a hot wire rubs on the case and shorts then the fuse should blow rather than the frame becoming hot. I believe the variation on the line voltage coming in from the power company is tried to be within +/- 5%. You will also see 230V mentioned as well. Years ago, the voltage standard was 220V and 110V but now it is 240V and 120V and the numbers get used interchangeably. You show it with a ground symbol but if it is relying on the safety ground to work it is illegal - electrically the neutral and the safety ground are at the same potential so it will let the motor and light operate if this is the case, but like I said, it is not legal.Ģ40V will not damage your welder. In your circuit drawing: Is the motor a 220V or 110V motor? Is the bulb a 120V bulb? If so, then there should be a neutral line present (usually a white wire) to establish 110/120V for these devices. No neutral is involved but the safety ground is to be present. If there is a fault it will keep the device at ground potential so no shock hazard exists.Ģ20/240 volt circuits do not require a return, the current goes out one line and back on the other line.

It is never intended to carry operating current and will only carry current if there is a fault in device. The ground is also called the safety ground is is usually a bare or green wire attached to the metal frame of the device. The return line in electrical circuits is typically called the neutral in 120V circuits.

Vintage doall bandsaw parts