O Definitions

Definition Categories

Off set

An off set in a vertical drain pipe (stack) is a change in direction in the pipe from vertical to an angle other than vertical then back to vertical. Off sets are most often used to run a stack around an obstruction (such as a wall or beam) that cannot be drilled or notched. An offset that is not more than (≤) 45 degrees from vertical is defined to be vertical.

Ohm’s law

Ohm’s law expresses the relationship between characteristics of an electric circuit.


An outlet is a connection point where electricity is taken for use. An outlet could be a receptacle, or a light fixture box, or junction box connected to an oven, or an air conditioning condenser disconnect box. Switch boxes, junction boxes, and panelboards are not outlets.

Overcurrent protection device

An overcurrent protection device is a device that automatically interrupts the flow of electricity if the current flowing through the device exceeds a design maximum amount. Common examples in residential electrical systems are fuses and circuit breakers.