Miller Electric KC237900 manual Highon Frequency OFF, High Frequency

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)

HIGHON

FREQUENCY

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.

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