Importance of correct polarity with light fixtures

Electrical · Lights, Outlets and Switches · printed page 104 (PDF page 105)

Book index entries

Electric Light Fixtures – Importance of Correct Polarity Electric Polarity Importance on Light Fixtures Light Fixtures – Importance of Correct Polarity Polarity – Importance on Light Fixtures

Text in the illustration

correct polarity
only the button at the bottom of the light socket is hot - a person is much less likely to touch this than the collar
collar
light socket
neutral
hot
reversed polarity
the entire light fixture collar is hot and easily touched if the light switch is on (particularly as the bulb is being screwed in)

Generated explanation

The illustration compares correct and reversed polarity at two screw-base light sockets, with a bulb and insertion arrow above each socket. On the left, a green check identifies correct polarity: the hot conductor connects to the bottom center contact button and the neutral conductor connects to the threaded collar. On the right, a red cross identifies reversed polarity, with the hot conductor connected to the collar and the neutral connected to the bottom contact. The annotations explain that an energized collar is more readily touched than the bottom contact, creating a shock hazard when a bulb is screwed in with the light switch on.