Graco EQ300C manual See Refilling the Pot with Abrasive, See Setting Up the Equipment

		Troubleshooting
Problem	Cause	Solution
No abrasive flows from the	The pot does not have a sufficient	See Refilling the Pot with Abrasive, page
nozzle during blast mode.	amount of abrasive.	18.
	The system is not properly set up.	See Setting Up the Equipment, page 11.
		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.
	There is an obstruction in the	See Flushing the Diaphragm Valve, page
	media circuit.	29.
	The diaphragm valve is not	See Repairing the Diaphragm Valve,
	working.	page 30.
	There is blockage inside the pot or	Make sure the ball valve is closed, then
	inside the abrasive hose between	disconnect the cam-lock coupler. Open
	the pot and the panel.	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 19).
		Thoroughly flush the pot and the media
		hose after draining media and water.
No blast air flow when the	The blast regulator is not adjusted	Adjust the blast regulator to the desired
blast control is engaged.	to the correct pressure.	pressure while the blast control is
The water pump cycles		engaged.
while the blast control
	The tubing from the main	Confirm that the tubing from the blast
engaged.
	air regulator is not properly	regulator to the main air regulator is
	connected.	intact. See Hose Schematic, page 39.
	The blast air regulator is	Replace the blast air regulator (Kit
	malfunctioning.	17C625).
	The main air regulator is	See Repairing the Main Air Regulator,
	malfunctioning.	page 28 (EQ600 – Kit 17C131, EQ300
		– Kit 17C129).
No blast air flow when the	The air supply is inadequate.	Make sure the air inlet pressure gauge
blast control is engaged.		reads 100-125 psi. If the gauge does
The water pump does not		not read 100–125 psi, check the air
cycle while the blast control		compressor for proper setup.
engaged.
	The Emergency Stop is engaged.	Disengage the Emergency Stop.
	The electric blast control circuit is	Inspect the hose cable for damaged or
	malfunctioning.	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).

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