AMI 415, Operation Manual, Page: 10 / 53

Model 415
Operation Manual
Document No. 740084
Revision N
5
3. RF PROTECTION
AMI policy is to comply with the IEC (and thus FCC) regulations. Our design rules and
procedures include testing and observing this area. We can assure our customers that
every effort has been made to reduce RF emissions to the absolute minimum from our power
sources.
However, this does not mean that a user will not have occasional problems with RF
interference with other equipment due to the use of our equipment. This is the nature of RF
starting.
Most RF noise interference problems are going to be either set-up related or caused by poor
or no filtering on the behalf of the equipment that is being disrupted. Most interference
problems are easily correctable but each one must be looked at on a “case by case basis.”
4. EMI SUPPRESSION
The M-415 is equipped with a heavy-duty Pi-Network filter, connected to the input power
line, to prevent propagation of EMI either into or out of the M-415. The all-metal enclosures
and internal shields prevent radiated EMI.
1.4 SHOCK HAZARD WARNING
As already stated in this manual “High Voltage” is present on exposed internal terminals. The
ELECTRODE (tungsten) and tube weld head rotors (M-8, M-9) are also an “exposed terminal” and
by its nature the GTAW process requires electrical potential to be present on the electrode during
arc starting and of course during the welding.
All AMI Power Supplies contain a “bleeder” circuit to ground any residual potential after welding or
after an aborted or bad “arc start” attempt. However, these circuits take a few seconds to operate
or COULD FAIL. Do not depend on them to prevent electrical shock.
“THE ELECTRODE SHOULD ALWAYS BE CONSIDERED A POSSIBLE SHOCK HAZARD”.
This is especially true when ever the system is in “weld sequence” ready to weld, is welding, or
has just finished welding. However, equipment/component failure, system abuse, or improper
maintenance could result in electrical potential at the weld head “even when not in weld sequence”.
The users/operators of this equipment must take all precautions necessary to avoid contact with
the ELECTRODE at “ALL TIMES”. The only exception is when actually replacing or adjusting the
electrode and this should be done “WITH THE POWER TURNED OFF”.
If performed with the power “ON” the system must be in test mode out of weld sequence and the
USER MUST OBSERVE COMMON SAFETY PRACTICES such as grounding the electrode to
insure discharge before actually touching it. REMEMBER, there is a “POSSIBLE” shock hazard in
all welding power supplies at “ALL” times.
Most AMI Power Supplies feature High Frequency (HF) Arc Starting. This is a High Voltage/High
Frequency electrical transmission process. To eliminate any HF shock possibility “AVOID ALL
CONTACT” with the Welding WORK (ground), the ELECTRODE or the WELD HEAD during arc
start.