Graco HFRL, Setup And Operation Manual

Page: 52 / 142

Troubleshooting
52 3A2175Z
Material imbalance. Inadequate flow from pump; cavita -
tion
Increase fluid supply to proportioning pump:
•
Use 2:1 supply pump
•
Use minimum 3/4 in. (19 mm) ID supply hose, as
short as practical
Fluid is too thick. Consult your material supplier for
the recommended fluid temperature to maintain a
viscosity of 250 to 1500 centipoise.
Clean inlet strainer screen
Worn pump inlet valve ball/seat or gasket
Pressure relief/circulation valve leak -
ing back to supply
Remove return line and determine if flow is present
while in SPRAY mode
Erratic pump movement Pump cavitation Feed pump pressure is too low. Adjust pressure to
maintain 100 psi (0.7 MPa, 7 bar) minimum.
Pump output low Obstructed fluid hose or gun; fluid
hose ID too small
Open, clear; use hose with larger ID
Worn piston valve or intake valve in
displacement pump
See pump manual 3A0019
Inadequate feed pump pressure Check feed pump pressure and adjust to 100 psi (0.7
MPa, 7 bar) minimum
Power Supply System
No power received from DC
power supply
Defective power supply Check circuit breaker. Check power supply. Replace
power supply.
No power to MCM, heat
zones, or tanks
Circuit breaker is tripping Check circuit breaker for tripping and defects. Diag -
nose cause of circuit breaker tripping before reset -
ting it. Replace defective parts if required.
Problem Cause Solution