Telwin PCP 28 Manual De Instrucciones página 8

cycle;
- shape and size of workpiece between the arms;
- gap between the arms (adjustable in PTE - PCP 28 models);
- length of arms (see technical data).
Failing precise knowledge, you should run some spot welding tests using sheets
having the same quality and thickness as the job to be performed.
Where possible, choose high voltage (using the "POWER" settings) and short times
(using the "CYCLES" settings).
6.3 PROCEDURE
- Disable the spot welding machine main switch (pos. "I"); the display will come on:
if the "START" icon is visible, the power supply is correct and the spot welding
machine is ready but not yet enabled.
- Before pressing the START button in FIG. D1-5 it is possible to select one of two
different machine operating modes: press the "MODE" button in FIG. D1-3 and
select "REDUCED" mode ("POWER" and "CYCLES" icons only) or "EXTENDED"
mode (all the welding parameters are enabled).
- Press the "START" button and turn the cycle selector to welding (fig D1-6).
- Set the welding parameters.
- Position the sheet metal to be spot-welded on the electrode.
- Press the pedal at stroke end (PTE model), or the pedal valve (PCP model) to
obtain:
A) closing of the sheet metal between the electrodes using the preset force;
B) passage of the welding current at the preset intensity and duration (time),
indicated by the switching ON and OFF of the icon in FIG. D2-11.
- Release the pedal a few seconds (0.5 ÷ 2s) after the icon switches off (end of
welding); this delay (maintenance) confers improved mechanical properties to the
spot weld.
The spot weld is deemed to have been performed correctly when a piece undergoes
a traction test and causes the extraction of the welding point kernel from one of the
two sheets.
6.4 MANAGEMENT OF THE PROGRAMMES IN "EXTENDED" MODE
6.4.1 Saving the spot welding parameters
- Start from the initial free programme identified by the acronyms "PCP" or "PTE" in
the centre of the display, and set the desired welding parameters.
- Press the "MODE" button repeatedly until the disc icon comes on (FIG. D2-15),
then hold the "MODE" button in this position: the welding parameters will be
saved to the first available customised programme, for instance "PRG 001"; the
programme will be saved immediately and can be retrieved using the "PRG 001"
icon in the centre of the display.
NOTE: the parameters of a free programme can be viewed using the "MODE" button
and modified using the "+" and "-" buttons; the parameters of a customised programme
can be viewed using the "MODE" button and modified following the procedure seen
in the paragraph below.
6.4.2 Modifying the spot-welding parameters on a customised programme
- Starting from the customised programme identified by the name "PRG ---" in the
centre of the display, press and hold the "MODE" button until the acronym "PRG"
starts flashing;
- confirm the programme number using the "MODE" button and modify the displayed
parameters;
- on completing the modifications, press and hold the "MODE" button until the
crossed disc icon is displayed (DO NOT SAVE);
- press "MODE" again to display the disc icon (SAVE) then press and hold "MODE"
to confirm.
6.4.3 Retrieving a programme
- Starting from any programme, press and hold the "MODE" button until the
acronym "PRG" starts flashing, then select the number of the programme to be
retrieved using the "+" and "-" buttons: the numbers correspond to the customised
programmes whilst the acronym "DEF" is the default or free programme.
- Press and hold the "MODE" button to confirm.
6.4.4 Cancelling a programme
- Starting from any programme, press and hold the "MODE" button until the acronym
"PRG" starts flashing, then select the number of the programme to be cancelled
using the "+" and "-" buttons.
- Press and hold the "+" and "-" buttons simultaneously to cancel the programme
parameters.
NOTE: the parameters of the "DEF" or free programme cannot be reset: pressing the
"+" and "-" buttons simultaneously will load the factory default settings.
7. MAINTENANCE
WARNING! BEFORE
OPERATION MAKE SURE THE SPOT-WELDER HAS BEEN SWITCHED OFF AND
DISCONNECTED FROM THE MAIN POWER SUPPLY.
In the versions driven by pneumatic cylinder (PCP models) it is necessary to
lock the main switch in the "O" position with the supplied padlock.
7.1 ROUTINE MAINTENANCE
ROUTINE MAINTENANCE CAN BE CARRIED OUT BY THE OPERATOR
- Adjustment/reset of electrode tip diameter and profile.
- Electrode alignment checks.
- Electrode and arm cooling checks (NOT INSIDE THE SPOT-WELDER).
- Checking the spring load (electrode force).
- Exhausting of condensation from the compressed air intake filter.
- Cooling check on cables and clamp.
- Check integrity of the spot welder and clamp power cable.
- Replacement of the electrodes and the arms.
- Periodic check of the level in the cooling water tank.
- Periodic check of the total absence of water leaks.
7.2 EXTRAORDINARY MAINTENANCE
EXTRAORDINARY MAINTENANCE OPERATIONS SHOULD BE CARRIED OUT
ONLY AND EXCLUSIVELY BY EXPERT OR SKILLED ELECTRICAL-MECHANICAL
TECHNICIANS.
WARNING! BEFORE REMOVING THE SPOT WELDER PANELS AND
WORKING INSIDE THE MACHINE, MAKE SURE THE SPOT WELDER IS OFF AND
DISCONNECTED FROM THE ELECTRIC AND PNEUMATIC (if present) POWER
SUPPLIES.
Carrying out checks while the inside of the spot welder is live can cause serious
electric shock due to direct contact with live parts and/or injury due to direct contact
CARRYING OUT ANY MAINTENANCE
with moving parts.
Periodically and as frequently as required by the use and environmental conditions,
inspect inside the spot welder and remove the dust and metal particles that have
deposited on the transformer, thyristor module, diode module, power terminal board,
etc. using a jet of dry compressed air (max. 5 bar).
Do not direct the jet of air towards the electronics boards; clean them with a very soft
brush and appropriate solvents, if necessary.
At the same time:
- Make sure the wiring does not show signs of insulation damage or loose or oxidized
connections.
- Lubricate the joints and the pins.
- Make sure the screws that connect the transformer secondary with the arm-holding
joints are tight and that there are no signs of oxidation or overheating; do the same
for the arm locking and electrode-holder screws.
- Make sure the screws that connect the transformer secondary with the output bars
/ wires are tight and that there are no signs of oxidation or overheating.
- Make sure the transformer secondary screws (if present) are tight and that there
are no signs of oxidation or overheating.
- Make sure the cooling water circulation is correct (minimum requested flow rate)
and that the piping is perfectly sealed.
- Check for possible air leaks.
- After having carried out maintenance or repairs, restore the connections and wiring
as they were before, making sure they do not come into contact with moving parts
or parts that can reach high temperatures. Tie all the wires as they were before,
being careful to keep the high voltage connections of the primary transformer
separate from the low voltage ones of the secondary transformer.
Use all the original washers and screws when closing the casing.
8. TROUBLESHOOTING
IF THE SPOT-WELDER DOES NOT RUN PROPERLY AND BEFORE PERFORMING
A THOROUGH MACHINE CHECK OR GETTING IN TOUCH WITH THE AFTER
SALES SERVICE CENTER, CHECK WHETHER:
- with the spot welding machine main switch closed (pos. "I") the display is ON; if this
is not the case, the problem is in the power line (cables, plug and socket, fuses,
excessive voltage drop etc.).
- no alarms have been triggered; if this is the case, wait for the "START" icon to light
up and press the button to restart the spot welding machine; check that the cooling
water is circulating correctly and decrease the duty cycle ratio as necessary; check
for the presence of compressed air (PCP mod. only); check that the voltage is
compatible with the value indicated on the rating plate ± 10%.
- with the pedal or cylinder enabled, the electric control actuator closes all the
terminals (contacts) and sends the required consent to the electronic card: spot
welding icon ON for the set time.
- the elements of the secondary circuit parts (arm-holder – arms – electrode holder
moulds) are not working efficiently due to loosened or rusted screws.
- the welding parameters (electrode force and diameter, welding time and current)
are suited to the job being done.
In PCP models check also whether:
- the compressed air pressure is lower than the triggering limit of the safeguard
device;
- the cycle selector is erroneously in position
not weld);
- the start-up push-button
has been closed whenever the following protection/safety devices have triggered:
a) power failure;
b) lack of/insufficient compressed air pressure;
c) overheating;
d) overload or underload of delivered voltage.
- 8 -
(pressure only - spot-welder does
has actually been pressed after the general switch