Section 5 - Fault Finding And Maintenance; Machine Operation; Welding Problems - NewArc RT5000 Instruction Manual

SECTION 5 — FAULT FINDING AND MAINTAINANCE

5.1 Machine operation

Most problems with the RT4000/RT5000 can be over-
come by following the procedures below.
No Digital Display on switch on.
Check that the machine is attached to a work-
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ing mains supply that it is correctly plugged in
and any isolator switches are closed.
Check the condition of the 2A fuse on the rear
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panel of the machine and replace if necessary.
Note : make sure the fuse is replaced with one of
the correct type and rating. It should be a 32 x
6.3mm (1¼" x ¼") ceramic bodied type with a rat-
ing of 2A 'slow blow'
Have a competent electrician check that there
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are no mains fuses or overload devices inter-
rupted, that the mains plug is fitted correctly
and that there are no loose wires or connec-
tions, check that there are no breaks in the
mains cable.
Digital display lit but no output.
Make sure that the display is not reading 'HOT',
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if it is, it means that the RT4000/RT5000 has over-
heated, normally by exceeding its 'Duty Cycle',
and the power stages of the machine have
been shut down. In this case, leave the ma-
chine switched on until it has cooled down, if
you turn the machine off, the cooling fans will
be turned off and the cooling down period will
be lengthened considerably.
Note : If the RT4000/RT5000 is overheating on a
regular basis or at current settings below the maxi-
mum, this would usually indicate that the inside of
the machine is choked with dust and therefore not
being cooled correctly. For information about
cleaning the dust out of the RT4000/RT5000 please
refer to the relevant part of section 5.3.2, the three
monthly service schedule.

5.2 Welding Problems

MMA
If problems with the RT4000/RT5000's operation while
welding are experienced, first refer to the informa-
tion in paragraph 3.2 in the installation section and
paragraphs 4.3.1 and 4.3.2 in the operating section
and the fault finding procedure earlier in this sec-
tion.
Most problems with MMA welding are the result
•
of not setting the correct welding parameters
for the welding rod being used. All welding rod
packets have information on them in symbolic
format , giving suitable current range, polarity
and type of weld (normally called 'position'). If
you are in doubt about what these symbols
mean, ask your welding rod supplier to explain
them. Choose an initial current setting towards
the middle of the quoted range and if neces-
sary practice on a piece of scrap the same
thickness as the job to be welded.
TIG
If problems with the
while TIG welding are experienced, first refer to the
information in paragraph 3.2 in the installation sec-
tion and paragraph 4.3.3 in the operation section.
The common problems with TIG welding are poor
striking, porosity and poor appearance of the
weld. If you are experiencing any problems with
TIG welding follow the check list below, this will
cure most problems :-
If the unit is suffering from poor striking, check
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that all power leads are connected properly,
check that there is sufficient gas flow and that
the correct gas is being used, check that the
earth clamp is making a good connection to
the work-piece.
If there is porosity in the weld or the final weld is
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of poor appearance, check that there is suffi-
cient gas flow and that the correct gas is being
used, check the condition of the TIG torch, par-
ticularly the gas hose. Make sure that the collet
or gas lens in the torch head is not blocked in
anyway. Check all gas connections are secure
and that there are no leaks, use a leak detect-
ing spray on all connections if necessary.
Any welding problems not covered above must be
brought to the attention of a qualified Welding En-
gineer, if the problem still persists have the
RT4000/RT5000 checked by a trained New-Arc ser-
vice engineer.
RT5/4000
RT4000/RT5000's operation
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