Glossary of Terms - O

Ohm - The unit of measure for resistance.

Ohm's Law - Voltage equals resistance multiplied by current.

Oil - When relating to a liquid-filled transformer, refers to mineral oil.

Oil Fuse Cutout - A zero awaiting (expulsion) interrupter that is used under oil; expulsion Bay-O-Net; Cartridge Fuse.

Oscillogram - A record made of an oscillograph.

Oscillograph - A device used for recording and measuring the instantaneous values of a rapidly varying electrical quantity as shown by its corresponding waveform.

Overvoltage - A voltage above the normal rated voltage or the maximum operating voltage of a device or circuit. A direct test overvoltage is a voltage above the peak of the line alternating voltage.

Glossary Index