What happens when Phase and Neutral are reversed ?

Read: What is ghost voltage?

Three pin North American polarized receptacle
Figure 1: Three pin North American polarized receptacle

Read: Earth resistance calculation for a single electrode

Non-polarized (a, c) and polarized (b) plugs
Figure 2: Non-polarized (a, c) and polarized (b) plugs

Read: High impedance in earth ground wire due to magnetic field

Three pin non-polarized and polarized two pin plugs
Figure 3: Three pin non-polarized and polarized two pin plugs

Read: Circuit breaker trip due to control circuit ground fault

Lamp outer metal will be at neutral potential when correctly wired
Figure 4: Lamp outer metal will be at neutral potential when correctly wired
Appliance with built-in overload can remain energized after overload trip. Shown is a garbage disposer overload
Figure 5: Appliances with built-in overload can remain energized after overload trip
Accidental ground fault can cause motor to turn ON if phase and neutral are reversed
Figure 6: Accidental ground fault can cause motor to turn ON if phase and neutral are reversed

Read: Stray voltage: How does it originate?

How to check for polarity in a receptacle?

Read: Open neutral condition

Socket tester can be used to check polarity
Figure 7: Socket tester can be used to check polarity

Read: Power quality check using multimeter

Summary

Read: Isolated ground receptacle