Fronius TP 1500, Service Manual

Page: 49 / 117

49
Before closing the housing:
- mount the screws (2) with cup springs
(Fig.21)
Note! When mounting the cup
springs (3), make sure that they
are fitted in the correct position
(Fig.21)
Fig.21 Fitting the cup springs
(3)
(2)
- Open the housing (see the section headed: “Opening the housing”)
On the LCA15 board you will find the LED “I
soll
” (in English, would be “I
des
”). The
brightness of this LED “I
soll
” depends on the pre-set (i.e. “ des ired”) welding amperage.
- Set the welding-current dial to “Minimum”
- Plug the machine into the mains and shift the mains switch to “I”
- Slowly turn the welding-current dial towards Maximum.
- While doing this, watch LED “I
soll
” all the time
- LED “I
soll
” gets continuously brighter
- Potentiometer is OK
- LED “I
soll
” glows constantly
- Potentiometer has a short circuit / LCA15 board is faulty
- Replace potentiometer or LCA15 board
- LED “I
soll
” remains dark
- Potentiometer has an interruption / there is a break in the ribbon cable for the
FPA11 board / the LCA15 board is faulty
Important! The FPA15 board with ribbon cable belongs to the LCA15 board assembly.
- Replace the potentiometer, LCA 15 board or the FPA15 board
Checking the
potentiometer
ribbon cable
PE conductor
test
Checking the
secondary diode
(continued)
Warning! An elelectric shock can be fatal. This check is performed with the
machine switched on and the housing opened up. As long as the machine is
plugged into the mains, do NOT under any circumstance touch the power
source or any of its components.
Follow these instructions even after unplugging the machine from the mains.
The capacitors are still charged - and still very dangerous!
Fig.22 Testing the PE conductor