Ransburg RMA Indirect A12869 - Manual (Page 48)

RMA-303 Indirect Charge - Operation
43 LN-9268-11.4
N O T E
!
W A R N I N G
BRAKE AIR
Brake air is used to slow the turbine speed in
a minimum length of time. It is advantageous
for short cycle times during color change, or
may be used to reduce speed or stop the tur-
bine. Never operate brake air with the turbine
air on.
Approximate brake times to reduce the turbine
speed are shown in "Deceleration Time Chart"
in the "Introduction" section. These times are
based on 60 psi (413.7 kPa) and 100 psi (689
kPa) air pressure at the back of applicator.
ELECTROSTATIC VOLTAGE
The RMA-303 Indirect Applicator receives its
high voltage via high voltage cable A10560-
XX. The voltage is then passed through eight
(8) total resistors located in the A11343-XX
electrode assemblies mounted on the A12079
-00 high voltage ring. An ionized field is es-
tablished between the probe tips and the elec-
trically grounded bell cup as well as the elec-
trically grounded work piece.
Refer to the current MicroPak service manual
for detailed operating instructions, safety cau-
tions, and settings
> If paint defects occur, such as fatty edges or
picture framing, reducing the voltage should
be a last resort. To correct the problem, lead
and lag trigger adjustments should be opti-
mized first.
> The electrostatic voltage applied to the RMA
-303 will affect pattern size, transfer efficiency,
wrap and penetration into cavity areas. A set-
ting of 30-70 kV is appropriate for most appli-
cations.
TARGET DISTANCE
The distance between the RMA-303 atomizer
and the target will affect the finish quality and
efficiency. Closer distances give a smaller
pattern, wetter finish, and greater efficiency.
Greater distance will provide a large pattern
size and drier finish. The MicroPak control
circuit will enable the applicator bell to be op-
erated to within a few inches of the target with-
out adjusting the voltage setting. The recom-
mended target distance is 6 to 12-inches
(152.4-304.8mm). In general, allow 1-inch
(25.4mm) target distance for every 10 kV.
GENERAL OPERATING SE-
QUENCE
> It is recommended to leave bearing air on,
unless the applicator is being serviced or re-
moved for service.
Normally, for painting application, the process
sequence should always be:
•
Bearing air on (Always on)
•
Turbine air on
•
Turbine speed to application speed
•
Shaping air on
•
Start fluid flow off part
•
Voltage on
After spraying the object, the sequence should
be:
•
Voltage lowered to 40-50 kV
•
Fluid off
•
Shaping air to setback volume
•
Turbine speed to set back speed
•
(30,000 rpm recommended)