Tweco 200DC Inverter Arc Welding Machine - Manual (Page 20)

WELDSKILL 200AC/DC INVERTER
INSTALLATION, OPERATION AND SETUP 3-2 Manual 0-5207
!
WARNING COMPUTER
It is also possible that operation close
to computer installations may cause
computer malfunction.
3.06 High Frequency Interference
Interference may be transmitted by a high frequency
initiated or stabilised arc welding machine in the
following ways.
1. Direct Radiation: Radiation from the machine can
occur if the case is metal and is not properly grounded.
It can occur through apertures such as open access
panels. The shielding of the high frequency unit in
the Power Source will prevent direct radiation if the
equipment is properly grounded.
2. Transmission via the Supply Lead: Without
adequate shielding and filtering, high frequency energy
may be fed to the wiring within the installation (mains)
by direct coupling. The energy is then transmitted by
both radiation and conduction. Adequate shielding
and filtering is provided in the Power Source.
3. Radiation from Welding Leads: Radiated
interference from welding leads, although pronounced
in the vicinity of the leads, diminishes rapidly with
distance. Keeping leads as short as possible will
minimise this type of interference. Looping and
suspending of leads should be avoided wherever
possible.
4. Re-Radiation from Unearthed Metallic Objects:
A major factor contributing to interference is re-
radiation from unearthed metallic objects close to the
welding leads. Effective grounding of such objects will
prevent re-radiation in most cases.
3.07 Electromagnetic Compatibility
!
WARNING
Extra precautions for Electromagnetic
Compatibility may be required when
this Welding Power Source is used in a
domestic situation.
A. Installation and Use - Users Responsibility
The user is responsible for installing and
using the welding equipment according to the
manufacturer’s instructions. If electromagnetic
disturbances are detected then it shall be the
responsibility of the user of the welding equipment
to resolve the situation with the technical
assistance of the manufacturer. In some cases this
remedial action may be as simple as earthing the
welding circuit, see NOTE below. In other cases
it could involve constructing an electromagnetic
screen enclosing the Welding Power Source and
the work, complete with associated input filters.
In all cases, electromagnetic disturbances shall
be reduced to the point where they are no longer
troublesome.
NOTE
The welding circuit may or may not be
earthed for safety reasons. Changing the
earthing arrangements should only be
authorised by a person who is competent
to assess whether the changes will
increase the risk of injury, e.g. by allowing
parallel welding current return paths which
may damage the earth circuits of other
equipment. Further guidance is given in
IEC 60974-13 Arc Welding Equipment -
Installation and use (under preparation).
B. Assessment of Area
Before installing welding equipment, the user shall
make an assessment of potential electromagnetic
problems in the surrounding area. The following
shall be taken into account
1. Other supply cables, control cables, signalling
and telephone cables; above, below and
adjacent to the welding equipment.
2. Radio and television transmitters and
receivers.
3. Computer and other control equipment.
4. Safety critical equipment, e.g. guarding of
industrial equipment.
5. The health of people around, e.g. the use of
pacemakers and hearing aids.
6. Equipment used for calibration and
measurement.
7. The time of day that welding or other activities
are to be carried out.
8. The immunity of other equipment in the
environment: the user shall ensure that other
equipment being used in the environment
is compatible: this may require additional
protection measures.
The size of the surrounding area to be considered
will depend on the structure of the building
and other activities that are taking place. The
surrounding area may extend beyond the
boundaries of the premises.