PH/PHX-2 Manual
39
3. Safety Pressure Switch
Each Metering Pump has a Safety Pressure Switch set to 2,200 psi. for #123 pumps,
3,200 psi for #61 pumps. When the material system reaches this pressure, the Safety
Pressure Switch will remove power from the Directional Valve and Direction Indicator
Lights (Q, page 15). Lack of Direction Indicator Lights along with high pressure indicated
on one or both of the material Pressure Gauges (E, F, page 14) is an indication of an
over-pressure condition. The Safety Pressure Switches are a momentary design; when
the pressure bleeds off the Metering Pump Line will resume normal operation. However,
the cause of the over-pressure should be determined and corrected. The three most
common causes are:
a) Cavitations of the Metering Pump on the low pressure side causing high pressure
on the opposite side.
b) A restriction in the Spray Gun on the high pressure side.
4. Pressure/Material Imbalance
In summary troubleshooting this problem requires the applicator to:
a) Know what the NORMAL spray pressures are for the application in progress.
b) Determine what material is NOT exiting the Mixing Chamber.
c) Read the Pressure Gauge on the problem side and interpret the reading.
To Next Page
Loading...
