Tweco 186 DC Inverter - Manual (Page 33)

Manual 0-5237 3-3 INSTALLATION, OPERATION AND SETUP
INSTALLATION/SETUP 186 AC/DC INVERTER
3.06 High Frequency Interference
Interference may be transmitted by a high frequency initiated or stabilized 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 authorized 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.
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, signaling 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 pace-makers and hearing aids.
6. Equipment used for calibration and measurement.