N

N - Abbreviation for nano

Nano (N) - Prefix to unit of measure meaning 10-9

NEMP - Abbreviation for nuclear electromagnetic pulse

Neutral - Having neither positive nor negative electric charge. The neutral wire is generally bonded to earth ground at a building service entrance, but unlike the ground wire, the neutral wire also carries load current.

Noise - A signal frequency that may be riding on top of the power line sine wave. A number of systems use the power lines to carry signals and data to other locations. Attempts to filter out the "noise" may disrupt the current or future operation of these systems. Although it is seldom needed, it is wiser to provide line conditioning filtering immediately in front of sensitive equipment.

Normal mode voltage - Voltage appearing between the phase wires and neutral of the power system wiring.

NRTL - Abbreviation for Nationally Recognized Test Laboratory, one example of which is the Underwriter's Laboratories, Inc. (UL).

Nuclear electromagnetic pulse (NEMP) - Pulses of energy caused by nuclear explosions and intense solar activity. NEMP transients are much quicker (a faster rise time) than commonly occurring transients. Also called electromagnetic pulse (EMP).

O

Outage - A total break in the supply lasting from several milliseconds to many hours. Also referred to as a blackout or power cut.

Overvoltage - Sustained increases in the supply voltage, lasting more than a few seconds.

P