Tweco 200 ACDC Arcmaster(April2006) - Manual (Page 24)

ARCMASTER 200 AC/DC
3-4 April 13, 2006
3.07 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 minimize this
type of interference. Looping and suspending of leads
should be avoided where 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.
3.08 Duty Cycle
The duty cycle of a welding power source is the percentage
of a ten (10) minute period that it can be operated at a
given output without causing overheating and damage to
the unit. If the welding amperes decrease, the duty cycle
increases. If the welding amperes are increased beyond
the rated output, the duty cycle will decrease.
!
WARNING
Exceeding the duty cycle ratings will cause the
thermal overload protection circuit to become
energized and shut down the output until the
unit has cooled to normal operating
temperature.
CAUTION
Continually exceeding the duty cycle ratings
can cause damage to the welding power
source and will void the manufactures war-
ranty.
NOTE
Due to variations that can occur in
manufactured products, claimed performance,
voltages, ratings, all capacities,
measurements, dimensions and weights
quoted are approximate only. Achievable
capacities and ratings in use and operation will
depend upon correct installation, use,
applications, maintenance and service.