Before Welding - CEA Z Serie Manual De Instrucciones

9.4 Adjusting the electrode force
ZT - NKLT Turn the nut (pos. M, fig. 1) to the desired
value.
ZP - NKLP Turn the nut (pos. M, fig. 2) to the desired
value and adjust the air pressure by turning
the pressure reducer (pos. O, fig. 2). The cyl-
inder thrust (pos. Q, fig. 2) must compress
the spring (pos. L, fig. 2) previously adjusted.
NOTE: Before making adjustments, turn the supply switch
(pos. C, fig.1-2) on the "O" position and take off the rear
cover. When the operation has been completed, refit the
protective cover again and turn the supply switch to the
on "1" position.
The electrode force changes as indicated in the following
tables:
Arms length
[mm]
250
350
450
600
∆P
NKLP 22
∆F [daN]
[bar]
1 30
∆P: pressure increase
∆F: electrode force increase

10. Before welding

IMPORTANT: Before turning the unit on, check once more
that the supply voltage and frequency correspond to the
data on the machine plate.
The machine is already set up for welding.
Before operating proceed as follows:
10.1 ZT - NKLT
• Check that the arms are parallel.
• Check that water flows through the cooling circuit.
• Turn on the unit by activating the "ON-OFF" switch (pos.
C, fig. 1).
• Check that the LED of the "WELD/DO NOT WELD"
switch is turned on.
• Adjust the welding parameters according to the work
to be done beginning as a precaution with low current
values.
• Place the workpiece between the electrodes.
• Press the foot pedal. The bar (pos. N, fig. 1) compresses
the spring (pos. L, fig. 1) causing pressure between the
electrodes (pos. F, fig. 1) and closes the limit switch
(pos. I, fig. 1) which starts the welding cycle.
ZT 18-28 ZP 18-28
∆F [daN] x ∆P=1bar
F [daN]
220 37
155 27
122 21
90 16
NKLP 28 NKLP 48
∆F [daN] ∆F [daN]
37 44
10.2 ZP - NKLP
• Check that the arms are parallel.
• Check that water flows through the cooling circuit.
• Turn on the unit by activating the "ON-OFF" switch (pos.
C, fig. 2).
• Check that the LEDs on the control panel are on (fig. 3)
• Set the desired welding parameters (section 8.5.3) ac-
cording to the work to be done. By setting parameters
initiate as a precaution with low values of welding time
and current.
• Adjust electrode force (section 9.4).
• If necessary modify jumper setting.
• Place the workpiece between the electrodes.
• When the electric pedal is pressed (pos. R, fig. 2) the
welding cycle described in paragraph 8.3 is performed.
10.3 Calculation of the maximum welding
rating
Before starting the production, it would be adviseable to
check that the used welding rating doesn't exceed the
maximum welding rating allowed by the welder, causing
a too high overheating. The heating of the welder is the
function of the thermal load applied to the welder itself,
depending from both the used time and welding current
and the numbers of welds for unit of time. It is necessary
to know the used welding current which must be meas-
ured. With these different parameters it is possible to
define the I value, that is the equivalent thermal current
th
at the duty cycle of 100%". This value is calculated as
follows:
(weld. cycle per
=
I
th
The resulting value must be lower than the maxi-
mum thermal current I
data table. In the event that it is higher, the welding
cycle per minute must be reduced.
EXAMPLE 1 (1 welding program)
NKLP 28 400V 50Hz
Welding current = 7000 A
Welding time = 5 periods
10 welding cycle per minute
×
(5 10)
=
I
th
3000
ENGLISH
⋅
min. [per]) (weld. current [A])
3000
reported on technical
th MAX
2
⋅
(7000)
=
904 A
2
23