Graco EcoQuip 2 EQp Operation, Repair, And Parts page 24

Operation
Problem
No blast air flow when the
blast control switch (B) is
engaged. The water pump
does not cycle while the blast
control switch is engaged.
24
Cause
The air supply valve is closed.
The air supply is inadequate.
The pneumatic blast control circuit is
malfunctioning.
Solution
Disengage the emergency stop (Q).
Make sure the air compressor is capable of
supplying the minimum air flow requirement
for your system (see Technical Specifica-
tions on page 45, for more information).
Make sure the air inlet pressure gauge reads
100-150 psi (6.8–10.3 bar, 0.68–1.03 MPa).
If the gauge does not read 100–150 psi,
check the air compressor for proper setup
(consult your air compressor manual, see
Related Manuals on page 2.
Actuate the blast control switch (B) and
check for proper spool valve actuation in the
4-way solenoid 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 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,
ensure that the yellow tubing inside the con-
trol box is properly connected and clear any
obstructions. If the tubing is clean, replace
the 4-way solenoid valve.
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