Graco EcoQuip 300 Operation, Repair, And Parts page 23

Problem
Problem Problem
No abrasive flows from the
nozzle during blast mode.
No blast air flow when the
blast control is engaged.
The water pump cycles
while the blast control
engaged.
No blast air flow when the
blast control is engaged.
does not
The water pump does does
cycle while the blast control
engaged.
334143C
Cause
Cause Cause
The pot does not have a sufficient
amount of abrasive.
The system is not properly set up.
There is an obstruction in the
media circuit.
The diaphragm valve is not
working.
There is blockage inside the pot or
inside the abrasive hose between
the pot and the panel.
The blast regulator is not adjusted
to the correct pressure.
The tubing from the main
air regulator is not properly
connected.
The blast air regulator is
malfunctioning.
The main air regulator is
malfunctioning.
The air supply is inadequate.
not
not
The Emergency Stop is engaged.
The electric blast control circuit is
malfunctioning.
Troubleshooting
Solution
Solution Solution
See Refilling the Pot with Abrasive, page
18.
See Setting Up the Equipment, page
Make sure the pot pressure is properly
set. The pot pressure must be set 30
psi above the blast pressure. Make sure
the selector valve is set to BLAST. The
abrasive ball valve must be open. The
abrasive metering valve must be at least
1/8 turn open.
See Flushing the Diaphragm Valve, page
29.
See Repairing the Diaphragm Valve,
page 30.
Make sure the ball valve is closed, then
disconnect the cam-lock coupler. Open
the abrasive ball valve slightly and make
sure abrasive is flowing form the abrasive
hose. If not, follow the shut down
procedure (see Shutting Down, page
Thoroughly flush the pot and the media
hose after draining media and water.
Adjust the blast regulator to the desired
pressure while the blast control is
engaged.
Confirm that the tubing from the blast
regulator to the main air regulator is
intact. See Hose Schematic, page
Replace the blast air regulator (Kit
17C625).
See Repairing the Main Air Regulator,
page 28 (EQ600 – Kit 17C131, EQ300
– Kit 17C129).
Make sure the air inlet pressure gauge
reads 100-125 psi. If the gauge does
not read 100–125 psi, check the air
compressor for proper setup.
Disengage the Emergency Stop.
Inspect the hose cable for damaged or
shorted wiring. Check the battery and
control panel connections. Make sure the
DC power source is 12V. Check the 3A
fuse inside the control panel, and replace
it if necessary. Check the current flow in
the circuit. If current exists, replace the
relay (EQ5179).
11.
19).
39.
23