Graco EcoQuip EQ200T 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
The water pump does does
not not cycle while the blast not
control engaged.
334666C
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 to 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.
The Emergency Stop is
engaged.
The electric blast control circuit
is malfunctioning.
The pneumatic blast control
circuit is malfunctioning.
Solution
Solution Solution
See Refilling the Pot with Abrasive, page
See Setting Up the Equipment, page
Make sure the pot pressure is properly set.
The pot pressure must be set 30 psi (2 bar,
0.2 MPa) 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
See Repairing the Diaphragm Valve, page
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 from the abrasive hose.
If not, follow the shut down procedure (see
Shutting Down, page 19). 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.
See Repairing the Main Air Regulator, page
27.
Make sure the air inlet pressure gauge reads
100-125 psi (6.8–8.6 bar, 0.68–0.86 MPa). 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.
See Pneumatic Blast Control Circuit, page
Troubleshooting
18.
11.
28.
29.
42.
26.
23