In Open Circuit Operation, The Voltage At The Dc-Capacitors (24) Is Not Regular - Cebora POWER SPOT 5600 Service Manual

CEBORA S.p.A.

3.3.4 - In open circuit operation, the voltage at the DC-capacitors (24) is not regular.

To check the open circuit operation of the power source, you must measure the output voltage
directly on the DC-capacitors (24), since the output terminals (F) and (G) of the power source are
connected to this potential only at the moment of welding.
DC-capacitors (24) are normally discharged by the control, which inserts the discharge resistor
If this circuit does not work the DC-capacitors (24) remain charged for several hours.
TO DISCHARGE THEM MANUALLY, TEMPORARILY APPLY A RESISTANCE OF 470
OHM 50 W IN PARALLEL TO THE DC-CAPACITORS (24).
NEVER SHORT-CIRCUIT THE TERMINALS OF THE DC-CAPACITORS (24).
The large capacity of the DC-capacitors (24) may produce very high currents, even with just a
VOLTAGE ON THE DC-CAPACITORS (24) ADJUSTMENT TEST.
Terminals of the DC-capacitors (24) = same voltage used the last time welding was

performed, or standard voltage for the type of accessory applied to the power source (ex.: 40
Vdc for the gun provided).
Adjust the keys (A) or (B) to increase or decrease the programmed voltage, shown on display

(E). When the keys are released, display (E) flashes to indicate that the voltage on the DC-
capacitors (24) is changing to reach the programmed value. When the flashing stops, the
voltage on the DC-capacitors (24) has reached the programmed value.
♦ Check the flat cable between CN4 power board (12) and CN2 control board (2).
♦ Check the status of the relay RL2 on power board (12). In normal conditions it
must not be powered and its NC contact actually closed.
♦ With the power source off, check on CN2 of power board (12) to make sure
resistance of terminals 5 and 6 = approximately 60 ohm. If >Mohm (circuit
broken) replace discharge resistor (7). If 0 ohm (short-circuit) replace discharge
resistor (7) and power board (12).
♦ See POWER SUPPLY AND CONTROL BOARD (2) TEST and SERVICES
POWER SUPPLY TEST par. 3.3.1.
♦ Replace the control (2) and/or power (12) boards.
♦ Regular operation.
3.302.311
WARNINGS
(7) in parallel until the programmed voltage is reached.
few volts, with serious danger to the operator.
YES
NOTE
Correct?
NO
12
23/01/2015