Ransburg RMA Dual Purge Direct A12300 - Manual (Page 51)

RMA-303 Dual Purge/Direct Charge - Operation
46
Ransburg
LN-9263-08.5
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 turbine. 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 Rotary Atomizer receives a low
voltage control input from the MicroPak to control
the operating electrostatic voltage. (Refer to the
current "MicroPak" maual for detailed operating
instructions.)
TARGET DISTANCE
The distance between the RMA-303 atomizer
and the target will affect the finish quality and
efficiency. Closer distances give a smaller pat-
tern, 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 operated within a few
inches of the target without adjusting the voltage
setting. The recommended target distance is 6
to 12- inches (152.4-304.8mm). In general, allow
1- inch (25.4mm) target distance for every 10kV.
GENERAL OPERATING
SEQUENCE
Normally, for direct charge 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 30-50kV
• Fluid off
• Shaping air to setback volume
• Turbine speed to set back speed
(30,000 RPM recommended)
C A U T I O N
!
† It is recommended to leave bearing air
on, unless the applicator is being serviced
or removed for service.
NOTE
† If paint defects occur, such as fatty
edges or picture framing, reducing the volt-
age should be a last resort. To correct the
problem, adjustments to lead and lag trig-
ger adjustments should be optimized first.
† The electrostatic voltage applied to the
RMA-303 will affect pattern size, transfer
efficiency, wrap and penetration into cavity
areas. A setting of 30-100kV is appropriate
for most applications.