Ransburg RMA-560 Single_Dual Purge Direct A13364 - Manual (Page 27)

NOTE
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 isolated
from all other functions 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 operated system, that ground will
be the target object.
The directed conduction of the electric charge,
through its array of wires, cables, and equipment,
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 electrical ground, which will allow
the charge to dissipate as fast as it accumulates,
it may store the charge. When its electrical stor-
age 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
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 discharge through the air as a spark. A spark
may ignite the flammable atmosphere of a spray
area. The hazard area extends 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 simple, but vital matter to be sure that all con-
ductive objects within the spray area are grounded.
All cabinets, housing, bases, supports, and stands,
which are not by design, insulated from ground, be
connected directly and INDIVIDUALLY to earth
ground. Resting on a concrete floor or being
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 insulated
braided cable 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 insulator, but all components of
the system up to the insulator MUST be grounded.
† Ransburg recommends that ground
connections to earth ground be 3/4” in-
sulated copper braided wire. Grounds
between assemblies within a machine
should be run 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 between
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 secured to an earth ground.
This may be achieved by the use of a standard
ground clamp (properly secured), by brazing or
by piercing the structural component enough to
assure connection. All ground connections should
be made to the most conductive metallic structural
ground available.
To be sure that everything is properly grounded,
the following steps should be undertaken at least
daily:
1. Inspect all ground wires. Look for good, firm
joints at all points of connection. Look for
breaks in the ground wire. Repair all defects
IMMEDIATELY!
2. Inspect the floor or grates for excessive
accumulation of dried coating material or
other residue. If there is any, remove it!
RMA-560 Single/Dual Purge Direct Charge - Installation
Ransburg
LN-9278-13 24