Graco Inc EM390 instruction manual Fluid supply often to prevent running the pump

PROBLEM

CAUSE

SOLUTION

Electric motor labors when start-	Motor capacitor has failed	Replace the capacitor. See page 22.
ing, and trips building circuit
breaker or fuse
	Circuit board has failed	Replace the circuit board. See page 23.
Paint leaks into wet±cup	Throat packings are worn or damaged	Replace the packings. See page 18.
Excessive surging from spray gun	Spray tip or fluid filter is plugged	Disassemble and clean.
	Spray tip too big or worn	Change the spray tip.
	Paint too viscous	Thin the paint.
	Wrong type hose	Use minimum 50 ft. (15.2 m), static±free nylon
		hose (wire braid hose is unacceptable).
Not enough paint pressure	Pressure setting too low	Increase pressure.
	Spray tip too big or worn	Change the spray tip.
	Pressure control frozen2 or damaged by	Try to thaw, or replace pressure control.
	over±pressurization3
	Displacement pump worn or damaged	Replace the displacement pump. See page 18.
Tails or fingers in spray pattern	Pressure setting too low	Increase pressure.
	Fluid outlet filter is dirty or clogged	Clean the filter. See page 14 or manual
		307±273.
	Spray tip too big or worn	Change the spray tip.
	Fluid supply is low or empty	Refill and prime the pump. See page 10. Check
		fluid supply often to prevent running the pump
		dry.
	Paint too viscous	Thin the paint.
	Wrong type hose	Use minimum 50 ft. (15.2 m), static±free nylon
		hose (wire braid hose is unacceptable).
Paint runs or sags	Spray tip too big or worn	Change the spray tip.
Spitting from gun	Air in fluid pump or hose	Check for loose connections at pump intake and
		tighten. Then prime the pump. See page 10.
	Tip partially clogged	Clear the tip. See page 11.
	Fluid supply is low or empty	Refill and prime the pump. See page 10. Check
		fluid supply often to prevent running the pump
		dry.
Static sparking from the gun	Spray or work being sprayed is not prop-	Correct problem before continuing. Follow the
	erly grounded	warning section, FIRE OR EXPLOSION HAZ-
		ARD on page 3.

1The electric motor has an over±temperature switch which automatically resets upon cooling. If it opens and the electric motor shuts itself off, unplug the power supply cord and let the sprayer cool for 30 to 60 minutes. Always use the lowest pressure setting needed when spraying. Prevent overspray from restricting the motor air passages; check and clean often.

2Freezing results from failure to replace the water± base paint or flushing water with mineral spirits, and usually causes permanent damage to the pressure control.

3Over±pressurization results from (1) using less than 50 ft. (15.2 m) of nylon spray hose, (2) from using a wire braid spray hose, (3) from adding a shutoff de- vice between the pump outlet and the spray gun, (4) from attaching a spray hose to the pressure drain valve, or (5) from using a clogged or incorrectly as- sembled filter.

307-724 17