Emerson Damcos, Service Manual

Page: 50 / 144

Service Manual Damcos LPU: Troubleshooting Guide LPU
SM 8000-100-01 Ed 04 February 2017
50
Motor not stopping
Action: • The pressure on B-port is measured.
If the pressure is below 120 bar, while motor is running, see “Pump rendering too low (or no)
pressure in one or both directions” on page 51.
• Wires to the pressure switch are dismounted and connected to each others, simulating high
pressure.
Caution!
LPU-Power wires are supplied by 230 V. When LPU terminal (“open”) is energized in the
relevant direction, motor must stop after 7 - 12 seconds.
LPU-S-power must not be restarted before wires are disconnected.
LPU-D-power must not be restarted before power is disconnected and reconnected
again.
• If pressure switch is correctly connected, and the pressure is correct, check that pressure switch
is closing as required. Pressure switches must close at maximum 125 bar and break between 95
to 105 bar.
Adjust and if necessary replace pressure switches, see “Replace pressure switch” on page 109.
LPU-D-P-Net
If motor does not stop at all, the printed circuit board must be replaced, see “Replace Printed Circuit
Board” on page 105.
If the motor runs longer than normal, but then stops, the fault should be found in the position indica-
tor, the calibration of the analogue indicator or setup of extra time in circuit board. Check, that the
position signal is really “0” or “100”.
LPU-S-P-Net
If motor does not stop at all and pressure on B-port is above 125 bar, the printed circuit board must
be replaced, see “Replace Printed Circuit Board” on page 105.
If the motor runs longer than normal, but then stops, the fault should be found in the position indica-
tor, the pressure switch, the calibration of the analogue indicator or setup of extra time in circuit
board. Check that the position signal really is “100”.
LPU Power Control
Check that the pressure switch is correctly connected. See “Pump rendering too low (or no) pressure
in one or both directions” on page 51.