Emerson Damcos, Service Manual

Page: 63 / 144

Damcos LPU: Troubleshooting Guide LPU Service Manual
February 2017 SM 8000-100-01 Ed 04
63
Motor ”diving” in RPM in end position
Reason: Voltage too low, pump relief valve misadjusted, defective flow reducing valve (the displacement of
the pump is not reduced at high pressure), fault in motor, or faulty connection of motor. Possibly
fault in capacitor/connection.
Action: • Check voltage over the terminals during operation. If it is considerably below 220 V AC, the fault
is to be found here. Take corrective measures. (LPU can operate down to 185V at
60 Hz, but such a low voltage is an indication of something being wrong).
• Check connection of motor.
• Check connection of capacitor.
• Check the maximum pressure (connect a pressure gauge to the quick connection pressurised).
Possibly adjust relief valve to 150 bar.
• Dismount adjusting screw for speed control, check with a screwdriver that the ball bearing
behind this can be moved back and forth by pressing it.
Motor ”diving” in RPM as spring actuator opens
Reason: Voltage too low, mechanical resistance in ball bearing around pump, faulty connected motor or fault
in capacitor.