Pro Spot PR-8 - E. Trouble shooting; E1. Welding Problem Solutions

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Pro Spot PR-8
GB/US/2000-08 PRO SPOT
E. Trouble shooting
E1. Welding problems
Swaging (Operating Mode 1):
Nothing happens when the graphite
electrode touches the body sheet:
- Make sure that the earth connection is
correctly positioned.
- Check the power supply to the machine
(fuses, MCBs, plugs inserted etc.).
- See the section on fault tracing.
Washer welding (Operating Mode 2)
Severe burning of the metal
- Reduce the current.
The edge of the washer penetrates into
the body sheet:
- Reduce the pressure on the washer and
reduce the current.
Stud welding (Operating Mode 3):
The studs do not hold:
- Make sure that the stud and the earth
contact are on the same body part.
- Position the earth connection close to the
part to be welded.
- Increase the pressure on the stud and
increase the current. Note: the current
and the pressure must be matched.
- Grind the sheet - it may be covered with
something that prevents proper current
flow.
The studs burn through the sheet:
- Reduce the current.
- Increase the pressure on the stud.
- Grind the sheet for better current distribu-
tion.
Single electrode (Operating Mode 4)
Spot welds are not holding:
- Check the earth connection and make
sure that it is sufficiently close to the part
to be welded.
- Make sure that the earth connection is
secured to the supporting sheet and not to
the part to be welded.
- Start by welding the spot furthest away
from the earth connection and then work
towards the earth connection.
- Increase the pressure on the electrode,
and increase the current.
- Clean and sharpen the tip of the electrode.
- Check the power supply to the machine
(fuses, MCBs, plugs inserted etc.).
- Check that the welding cables are con-
nected to the correct polarity (+ and –).
Double electrode (Operating Modes
5 and 6)
The electrode burns through the mate-
rial:
- Replace the electrodes if they are too old.
- Check the air pressure: must be at least
6 bar.
Pressure for C-tong should be 5 bar(73
psi, see table on front panel).
- Check to see whether the electrode
clamping force is too low.