SanRex IA-3000TP-U3E, Operator'S Manual

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WARNING:
Explosives:
The high frequency section of this machine has an output similar to a radio
transmitter. The machine should NOT be used in the vicinity of blasting
operations due to the danger of premature firing.
WARNING:
Computers:
It is also possible that operation close to computer installations may cause
computer malfunction.
3.03.03 High Frequency Interference
Interference may be transmitted by a high frequency in an initiated or stabilized arc welding
machine in the following ways:
Direct Radiation
Radiation from the machine can occur if the unit is not properly grounded. The shielding
of the high frequency unit in the Power Source will prevent direct radiation if the
equipment is properly grounded.
Remedy: Keep the input power lines as short as possible. Enclose excessive lengths in
rigid metal conduit or equivalent shielding. The metal conduit should have a good
common ground to the welder ground.
Transmission via the Supply Lead
Without adequate shielding and filtering, high frequency energy may be fed back into the
wiring within the installation (mains) by direct coupling. The energy is then transmitted
by both radiation and conduction.
Remedy: Keep the work and torch leads as short as possible and as close together as
possible.
Radiation from Welding Leads
Radiated interference from welding leads, although pronounced in the vicinity of the
leads, diminishes rapidly with distance.
Remedy: Keeping leads as short as possible will minimize this type of interference.
Looping and suspending of leads should be avoided where possible when welding to avoid
producing additional interference.
Re-radiation from Unearthed Metallic Objects
A major factor contributing to interference is re-radiation from unearthed metallic objects
close to the welding leads.
Remedy: Effective grounding of such objects will prevent re-radiation in most cases.