Fronius TP 1500, Service Manual

Page: 38 / 117

38
Measuring, inspection and adjustment jobs - Checking
and setting the parameters on the welding sockets
Note! Whenever the LCA 15 board is exchanged, it is necessary to check and
set the maximum welding amperage.
- Shift the mains switch to the “O”
position and unplug the machine from
the mains
- Connect the shunt and power resistor
to the welding sockets of the power
source
- Set the welding current dial to Maximum
- Plug the machine back into the mains
and shift the mains switch to the “I”
position
- Select the welding process “rod
electrode welding”
- Measure the welding current using the
shunt and power resistor
- For a 0.5 sec period, the welding
current must rise to 160 A = Hot-Start-
current
- I
Hotstart
= 160 A
- Tolerance range = +/-5 A
- Following the welding current must
decrease to constantly 140 A =
maximum welding current
- I
max
= 140 A
- Tolerance range = +/-5 A
If I
Hotstart
and I
max
are not within the
tolerance range, this may mean that the
LCA15 board or the potentiometer are
faulty,
- or that I
max
is not set correctly.
If the maximum welding current (I
max
) is
too high or too low, set the maximum
welding current.
General remarks
Checking the
maximum
welding
amperage and
Hot-Start
+
-
Load resistor
load: 160 mOhm / P > 3.14 kW
S
h
u
n
t
Oscillo-
scope
+
Multimeter
TP 1500
Fig.1 Checking the maximum welding amperage
t
0.5 s
160 A
140 A
Hot-Start
function
Welding current
Fig.2 Hot-Start
Setting the
maximum
welding
amperage - Shift the mains switch to the “O” position and unplug the machine from the mains
- Connect the shunt and the power resistor to the welding sockets of the power source
- Set the welding-current dial to Maximum
Warnung! An electric shock can be fatal. This test is performed with the power
source switched on and the housing opened up. As long as the power source is
plugged into the mains, do NOT under any circumstances touch the power
source or any of its components. Follow these instructions even after
unplugging the power source from the mains. The capacitors are still charged -
and still very dangerous!