Ransburg RMA Direct A12867 - Manual (Page 39)

RMA-303 Direct Charge - Installation
LN-9266-11.3 36
EQUIPMENT GROUNDING /
SAFETY RECOMMENDATIONS
In electrostatic coating systems, the flow of
high voltage power from the power supply to
the atomizer is insulated from ground and iso-
lated from all other functions equipment. When
the voltage reaches the atomizer, it is trans-
ferred to the coating material where, by intro-
ducing a negative charge, it causes the atom-
ized fluid to seek the nearest positive ground.
In a properly constructed and operated system,
that ground will be the target object.
The directed conduction of the electric charge,
through its array of wires, cables, and equip-
ment, is accompanied by a variety of stray
electrical charges passing through the air by
various means such as: air ionization, charged
particles in the air and radiated energy. Such
charges may be attracted to any conductive
material in the spray area. If the conductive
material does not provide a safe drain to elec-
trical ground, which will allow the charge to dis-
sipate as fast as it accumulates, it may store
the charge. When its electrical storage limit is
reached, or when it is breached by external
circumstances (such as the approach of a
grounded object or person, or one at lower po-
tential), it may discharge its stored charge to
the nearest ground. If there is no safe path to
ground (such as a ground wire or braided ca-
ble) it may discharge through the air as a
spark. A spark may ignite the flammable at-
mosphere of a spray area. The hazard area
extend from the point of origin up to as much
as a twenty-foot radius. (See the NFPA-33 for
definition and limitations of a hazard area.)
It is a simple, but vital matter to be sure that
all conductive objects within the spray area
are grounded. All cabinets, housing, bases,
supports, and stands, which are not by de-
sign, insulated from ground, be connected
directly and INDIVIDUALLY to earth ground.
Resting on a concrete floor or being at-
tached to a building column may not al-
ways be sufficient ground.
In order to provide the best ground connection
possible, always attach a ground wire or insu-
lated braided cable t the terminal indicated by
the ground symbol and then to a proven
ground. Always check ground connections for
integrity. Some items, such as rotators and
paint stands, may be supported on an insula-
tor, but all components of the system up to
the insulator MUST be grounded.
NOTE - Ransburg recommends that ground
connections to earth ground be 3/4” insulated
copper braided wire. Grounds between as-
semblies within a machine should be ran to a
central point within the machine using #18
insulated stranded copper wire minimum. All
connections should be mechanically sound
and have less than 5 ohms of resistance be-
tween assemblies and the common point.
The resistance between the central point and
earth ground should be less than 5 ohms as
well.
Where items are mounted directly on structur-
al components such as building columns, the
ground connection MUST still be made. In
many cases the structural component may be
painted or coated with an insulated material
and in all cases, the equipment will provide
the necessary connection at one end, but the
user must be sure that the other end is se-
cured to an earth ground. This may be
achieved by the use of a standard ground