Ransburg MMA-303 Direct_Ind Charge Atomizer A12870 - Manual (Page 101)

MMA-303 Direct/Indirect Charge - Maintenance
LN-9269-11.3 98
General Problem Possible Causes Corrective Action
Low or No High 7. Faulty low voltage connections 7. Make sure quick disconnect electrical
Voltage (Cont.) (Usually indicated by MicroPak connection is aligned and clean.
feedback fault light) a. Check low voltage connection at cascade.
8. Faulty high voltage connection 8. a. Remove cascade and check continuity
between cascade connection and turbine
shaft.
9. MicroPak or cascade failure 9. Refer to "MicroPak" service manual for
detailed "Troubleshooting Guide".
10. Improper color change 10. Optimize color change.
(i.e., paint or solvent in dump
line)
Low Transfer 1. Low or no high voltage
1. Verify high voltage at bell cup edge. Normal-
ly
Efficiency (or light a high voltage setting of 70-100 kV is
coverage) appropriate for most applications.
2. Poor grounding of parts being 2. Verify that parts being coated are properly
coated grounded (the electrical resistance between
the part and ground must not exceed
1 megohm).
3. Excessive turbine speed 3. For optimum transfer efficiency and spray
pattern control, the bell rotational speed
should be set at the minimum required to
achieve proper atomization of the coating
material.
4. Excessive inner/outer shaping 4. Shaping air should be set at the minimum
air volume required to gently direct the spray
pattern toward the part being coated.
Excessive shaping air will cause some
atomized particles to "blow-by" the part or
bounce back onto the atomizer.
5. Excessive target distance
5. The recommended target distance is be-
tween
6-12 inches (152.4-304.8 Nm) (see "Target
Distance" in the "Operation" section of this
manual).
No Turbine Air 1. Turbine drive air not present 1. Verify supply air pressure.
2. Bearing air return signal not 2. a. Verify bearing air return signal.
present b. Increase bearing air supply pressure to
90 psig (± 10 psig) (620.5 ± 68.9 kPa).
3. Brake air is activated 3. Remove brake air signal (turbine air and
brake air must be interlocked to prevent
both from being used simultaneously).
Troubleshooting Guide — Direct Charge (Cont.)