Samlex America PSE-12275A - Manual (Page 9)

Page 8
AC POWER DISTRIBUTION AND GROUNDING
CAUTION! PLEASE NOTE THAT THE AC OUTPUT CONNECTIONS AND THE DC
INPUT CONNECTIONS ON THESE INVERTERS ARE NOT CONNECTED
(BONDED) TO THE METAL CHASSIS OF THE INVERTER. BOTH THE
INPUT AND OUTPUT CONNECTIONS ARE ISOLATED FROM THE METAL
CHASSIS AND FROM EACH OTHER. SYSTEM GROUNDING, AS RE-
QUIRED BY NATIONAL / LOCAL ELECTRICAL CODES / STANDARDS, IS
THE RESPONSIBILITY OF THE USER / SYSTEM INSTALLER.
Conductors for electrical power distribution
For single phase transmission of AC power or DC power, two conductors are required that
will be carrying the current. These are called the “current-carrying” conductors. A third
conductor is used for grounding to prevent the build up of voltages that may result in undue
hazards to the connected equipment or persons. This is called the “non current-carrying”
conductor (will carry current only under ground fault conditions)
Grounding terminology
The term “grounded” indicates that one or more parts of the electrical system are connected
to earth, which is considered to have zero voltage or potential. In some areas, the term
“earthing” is used instead of grounding.
A “grounded conductor” is a “current-carrying” conductor that normally carries current and
is also connected to earth. Examples are the “neutral” conductor in AC wiring and the
negative conductor in many DC systems. A “grounded system” is a system in which one of
the current-carrying conductors is grounded
An “equipment grounding conductor” is a conductor that does not normally carry current
(except under fault conditions) and is also connected to earth. It is used to connect the
exposed metal surfaces of electrical equipment together and then to ground. Examples are the
bare copper conductor in non-metallic sheathed cable (Romex ®) and the green, insulated
conductor in power cords in portable equipment. These equipment-grounding conductors
help to prevent electric shock and allow over-current devices to operate properly when
ground faults occur. The size of this conductor should be coordinated with the size of the
over-current devices involved
A “grounding electrode” is the metallic device that is used to make actual contact with the
earth. Other types of grounding electrodes include metal water pipes and metal building
frames.
A “grounding electrode conductor” is the conductor between a common single grounding
point in the system and the grounding electrode
“Bond” refers to the connection between the “grounded conductor”, the “equipment
grounding” conductors and the “grounding electrode” conductor. Bonding is also used to
describe connecting all of the exposed metal surfaces together to complete the equipment-
grounding conductors.