common wire

American  

[kom-uhn wahy^uhr] / ˈkɒm ən ˌwaɪər /

noun

Electricity.

1. a separate or extra wire serving to supply a smart thermostat with continuous power from a heating or cooling system, without interfering with the signals that alert the system to turn the heating or cooling on or off.

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Etymology

Origin of common wire

First recorded in 1870–75

Example Sentences

The most common wire gauges used in U.S. residential buildings are 14, 12 and 10.

From Seattle Times

This bottle was a mere ordinary bottle, with a common cork in its neck, into which a common wire had been inserted.

From Project Gutenberg

When all the hooks are down, each call bell is connected between the lower common wire and the tip side of the talking circuit individual to the corresponding station.

From Project Gutenberg

The ringing buttons at each station are connected between the tip of the plug at that station and the upper common wire.

From Project Gutenberg

Ignoring at first the pilot relay and the pilot lamp, it will be seen that each of the tip-spring anvils of the jacks is connected to a common wire 1 which is grounded.

From Project Gutenberg