Ransburg RMA Indirect A12869 - Manual (Page 35)

RMA-303 Indirect Charge - Installation
LN-9268-11.4 30
EQUIPMENT GROUNDING AND
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 and equipment .
When the voltage reaches the atomizer, it is
transferred to the coating material where, by
introducing a negative charge, it causes the
atomized fluid to seek the nearest positive
ground. In a properly constructed and oper-
ated system, that ground will be the target
object.
The directed conduction of the electric charge
through its array of wires, and equipment, is
accompanied by a variety of stray electrical
charges passing through the air by various
means such as: air ionization, charged parti-
cles 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
dissipate as fast as it accumulates, it may
store the charge. When its electrical storage
limit is reached , or when if is breached by
external circumstances (such as the ap-
proach of a grounded object or person, or
one at lower potential), 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 cable) it may ignite the flam-
mable atmosphere of a spray area. The haz-
ard area extends a twenty-foot radius. See
the NFPA-33 for definition and limitations of a
hazards 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, MUST be con-
nected directly and INDIVIDUALLY to earth
ground. Resting on a concrete floor or be-
ing attached to a building column may not
always be sufficient ground
.
In order to provide the best ground connection
possible, always attach a ground wire or insu-
lated braided cable to 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 and insu-
lator, but all components of the system up to
the insulator MUST be grounded.
Ransburg recommends that ground
connections to earth ground be 3/4” insu-
lated copper braided wire. Grounds be-
tween assemblies 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 then five (5) ohms of resistance be-
tween assemblies and the common point.
The resistance between the central point
and earth ground should be less than five
(5) ohms as well.
Where items are mounted directly on
structural components such as building
columns, the ground connection MUST
still be made. In many cases the structur-
al components may be painted or coated
with an insulated material and in all cases
the Ransburg equipment will be painted.
These coatings are insulating. The
ground connection must be as perfect as
possible. The indicated ground terminal
on the Ransburg equipment will provide
the necessary connection at on end but
the user must be sure that the other end is
secured to an earth ground . This may be
achieved by the use of a standard ground
clamp (properly secured), by brazing or by
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