Miller Electric KC237900 - Manual (Page 18)

OM-530 Page 14
condition resetting to Off is accomplished manually by
pushing the switch once, provided that an arc has not
been established. This control is designed to be taped to
the torch handle for convenient operation.
4-6. HIGH FREQUENCY SWITCH (Figure 4-1)
HIGH
FREQUENCY
ON
OFF
WARNING: USING HIGH FREQUENCY WITH
THE SHIELDED METAL ARC WELDING
PROCESS can result in serious personal in-
jury.
•
Place the HIGH FREQUENCY switch in the
OFF position before using Shielded Metal Arc
Welding process.
The attempted use of high frequency to estab-
lish an arc with a stick electrode could cause an
arc to form between the electrode holder and
operator.
The HIGH FREQUENCY switch provides two positions:
ON and OFF.
When the HIGH FREQUENCY switch is in the OFF po-
sition, high frequency will not be available. The OFF po-
sition should be used for Shielded Metal Arc Welding
applications. When the HIGH FREQUENCY switch is in
the ON position, high frequency will be in a ready status
and will be present when the contactor in the welding
power source is closed until an arc is established. The
ON position is normally used for Gas Tungsten Arc
Welding applications.
A. Basic And Pulser Models Only
When in the ON position, high frequency will be present
at the welding electrode when the fingertip control
(RCC-14) is closed. The high frequency unit will remain
energized until an arc is established, at which point it will
deenergize. If an arc outage occurs, high frequency will
automatically be present until a new arc is established.
B. Electroslope Models Only
WARNING: ELECTRIC SHOCK can kill; UN-
EXPECTED HIGH FREQUENCY DURING
PREFLOW can cause serious injury and
equipment damage.
•
Do not allow electroslope switch or other unit
control switch to be maintained closed during
preflow time.
•
Always close and immediately open control
switch to ensure that high frequency will not be
present during preflow.
If the unit is equipped with the optional electro-
slope and preflow timer, it is possible to have
high frequency present during preflow without
machine contactor energized.
When in the ON position, high frequency will be present
at the welding electrode when the momentary-contact
switch (RMLS-14) is closed. High frequency will remain
energized until an arc is established or only as long as
the momentary-contact switch is held closed. Provided
that an arc has been established, releasing the momen-
tary-contact switch will deenergize the high frequency. If
an arc is not established, the high frequency will remain
energized until an arc is established or until the momen-
tary-contact switch is pushed again shutting the unit
down.
4-7. HIGH FREQUENCY CONTROL (Figure 4-1)
HIGH
FREQUENCY
The HIGH FREQUENCY control is calibrated in percent
and determines the amount of high-frequency energy
that is available to initiate the arc. Rotating the control
clockwise increases the intensity of the high-frequency
energy. Normally the control needs to be adjusted only
initially.
IMPORTANT: As the high frequency is increased, the
possibility of causing interference with local radio and
television receivers also increases. It is recommended
that the HIGH-FREQUENCY control be set at as low a
position as practical while still maintaining a satisfactory
welding operation to avoid such interference.
4-8. METERS (Optional) (Figure 4-1)
The meters are provided to monitor the welding opera-
tion. They are not intended for exact amperage or volt-
age measurements. These meters are internally con-
nected to the output terminals. The voltmeter will indi-
cate the voltage at the output terminals, but not neces-
sarily the actual voltage at the welding arc (due to cable
resistance, poor connections, etc.). The ammeter will
indicate the amperage output of the unit.
4-9. PULSER SWITCH (Pulser Models Only)
(Figure 4-1)
The PULSES switch governs the operation of the pulse
unit. By placing the PULSES switch in the ON position,
the welding power source output amperage will pulse
between the background amperage level and the peak
amperage level. By placing the PULSES switch in the
OFF position, the welding power source output will not
pulse, but rather remain at the peak amperage level.
The PULSES switch may be placed in either the ON or
OFF position prior to or during the welding operations. If
the PULSES switch is placed in the ON position prior to
welding operations, the output amperage may be at ei-
ther the peak or background amperage level. If the
PULSES switch is placed in the ON position during weld
operations, the pulsing begins with the output amperage
remaining at the peak amperage level, then pulsing to
the background amperage level.
There is no interaction between the BACKGROUND
control, PULSES/SECOND control, % “ON TIME” con-
trol, or the PULSES switch and any of the other controls.