Graco EcoQuip 2 Vapor Abrasive Blast System Operation, Repair, And Parts page 26

Troubleshooting
Problem
Problem Problem
The pot pressure relief The water pressure regulator
valve is discharging is malfunctioning.
water.
The pressure relief valve has
failed.
No blast air flow when The adjustable blast regulator
the blast control switch is not adjusted to the correct
pressure.
(B) is engaged. The
water pump does cycle
The tubing to the main air
while the blast control
regulator is not properly
switch is engaged.
connected or there are air
leaks in the fittings or tubing.
The adjustable blast air
regulator is malfunctioning.
The main air regulator is
malfunctioning.
No blast air flow when The emergency stop (Q) is
the blast control switch engaged.
(B) is engaged. The
The air supply is inadequate.
water pump does
not cycle while the
blast control switch is
engaged.
The electric blast control
circuit is malfunctioning.
The pneumatic blast control
circuit is malfunctioning.
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Cause
Cause Cause
Adjust the water pressure regulator to 185 psi (12.75 bar,
1.275 MPa). If this adjustment is not possible, service the
water pressure regulator (see manual 309474).
Replace the pressure relief valve if weeping occurs at or
below 185 psi (12.75 bar, 1.275 MPa).
Adjust the blast regulator to the desired pressure while the
blast control is engaged.
See the
connection points.
Clean or replace the adjustable blast air regulator.
Disassemble the main air regulator and inspect
components. Replace or repair parts as necessary. See
Enclosure Box Parts, page
Disengage the emergency stop (Q).
Make sure the air compressor is capable of supplying
the minimum air flow requirement for your system (see
Technical Specifications, page 67
Make sure the air inlet pressure gauge reads 100-175 psi
(6.8–12 bar, 0.68–1.2 MPa). If the gauge does not read
100–175 psi, check the air compressor for proper setup.
Ensure proper 12V DC supply is connected, and at full
charge. Inspect cable for damaged or 'open' wiring. Check 3A
fuse and replace if necessary. Check for continuity through
connectors on the control box and all external cables. Check
continuity through the electric blast control switch (B) (the
switch is normally open). If all above items are functional,
replace the 4-way solenoid valve.
Actuate the blast control switch (B) and check for proper spool
valve actuation in the 4-way valve. If no actuation occurs,
check the blast control switch and twin-line by disconnecting
the yellow tube at the enclosure male quick disconnect and
engage the control switch. If no air comes from the fitting,
check the pneumatic blast control filter. If the filter is clean,
check for signal air at the blast control switch. Replace the
pneumatic blast control switch if signal air does not pass
through the valve when the handle is depressed. If the switch
is functioning, make sure the yellow tubing inside the control
box is properly connected and is clear of obstructions. If the
tubing is clean, replace the 4-way solenoid valve.
Solution
Solution Solution
Tubing Schematic, page 63. Check for leaks at
50.
for more information).
3A3489E