Ransburg RMA Direct A12867 - Manual (Page 41)

RMA-303 Direct Charge - Installation
LN-9266-11.3 38
eliminate moisture as a potential defect in
painted surfaces as well as extending equip-
ment life. Thus, it is recommended that air
heaters be installed into the atomizer air sup-
ply lines, i.e. turbine drive air, shaping air, and
seal air. The air heaters must be of sufficient
capacity, capable of raising the incoming air
temperature at least 40°F (4.4°C) at a flow
rate of 60 SCFM per applicator.
The actual air heater process setting depends
on applicator fluid flow rate load, booth condi-
tions, turbine airflow settings, and incoming air
temperature. The heater should be set as low
as possible, sufficient to maintain the applica-
tor surface temperatures above the dew point
in the booth.
Example: With the incoming air temperature
at 72°F (22.2°C), and RMA-303 with 65mm
bell cup rotating unloaded at 60 krpm has a
turbine outlet temperature drop of approxi-
mately 28°F (-2.2°C) @ 40 krpm unloaded,
∆
~14°F (-10°C). Referring to the ASHRAE
Psychrometric chart, the saturation
temperature range (dew point) of a spray
booth maintained at 70-75°F/65-70% RH is 62
-68°F (21.1-23.9°C/65-70°RH is 16.7-20°C).
Thus it is almost certain that the surface
temperatures of the applicator will fall below
the dew point of the booth, and an air heater
will be needed in this case.
To prevent condensation, an Ransburg air
heater assembly (A11065-05) should be
assembled after the air filters. (Reference the
current “Air Heater Assembly “ service manual
for further information.)
NOTE - Failure to use an air heater may
cause damage to equipment or ruin the
finished component being processed.
NOTE - Connect air heater to turbine air
tubing.
A11065-05 Air Heater