What is Grounding and Bonding? T&B.
Abstract: This article discusses the two types of grounded electrical
systems: a wiring system ground and an equipment ground. Grounding helps
protect electrical equipment and circuits from exposure to high voltages.
A wiring system ground consists of grounding a wire from the electrical
system. This reduces the voltage sustained on a circuit that might occur
from lightning or other dangerous voltages. A system with a grounded wire
will automatically open a circuit if a ground fault occurs in an ungrounded
conductor. The article explains which wire should be grounded depending
on the electrical system.
An equipment ground is the "bonding" of non-current carrying
metal parts and connecting it to system grounding electrode. This connection
provides a low impedance path for fault current to flow in case the over-current
devices need to open the circuit. This bonding together of metal enclosures
is required for grounded and ungrounded electrical systems.