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

Page 17
Image 17
Graco Inc EM390 instruction manual Fluid supply often to prevent running the pump