Miller Electric RHC-23 Operator Controls, Maintenance, Operation A. General, Contactor Switch

SECTION 3 − OPERATOR CONTROLS

3-1. OPERATION A. General

When a Remote Hand Control is being used, it should be noted that on most welding power sources or welding generators, the Remote Hand Control functions as a fine amperage or voltage adjustment of the Amperage or Voltage Adjustment Control setting on the welding power source or welding generator. For example, if the Amperage or Voltage Adjustment Control on the weld- ing power source or welding generator is set at the mid- point position, the Remote Hand Control will provide (from its minimum to maximum positions) fine adjust- ment of one half of the welding power source or welding generator output. If full adjustment of the maximum out- put of the welding power source or welding generator from the Remote Hand Control is desired, it will be nec- essary to rotate the Amperage or Voltage Adjustment Control on the welding generator to the maximum posi- tion. The Remote Hand Control dial is calibrated in per- centage in increments of ten from 0 to 100 percent.

On some welding power source or welding generators the Amperage Voltage Adjustment Control on the Weld- ing power source or welding generator is inoperative when a Remote Hand Control is connected in the weld- ing power source or welding generator control circuitry. In this situation, the Remote Hand Control provides complete control from the minimum to the maximum output of the welding power source or welding generator rather than fine adjustment of the Amperage or Voltage Adjustment control setting on the welding power source or welding generator.

To determine in which way the Remote Hand Control af- fects the operation of the welding power source or weld- ing generator, refer to the welding power source or weld- ing generator circuit diagram and/or instruction Manual.

B.Remote Hand Control Of Two Welding Power Sources

Remote amperage or voltage control of two welding power sources from one Remote Hand Control is made possible through the use of Remote Hand Control hav- ing two rheostats. These Remote Hand Controls are identified by a model suffix of -2, and are designed to si- multaneously control two identical welding power sources. These Remote Hand Controls have two rheo- stats coupled on a common control shaft. Rotating the knob on the Remote Hand Control simultaneously ad- justs each rheostat in the control to the same value, thus making possible remote control of two welding power sources from a single Remote Hand Control.

IMPORTANT: When a Remote Hand Control is used, refer to the Instruction Manual of the welding power source or welding generator for additional operational information.

3-2. CONTACTOR SWITCH

WARNING: ELECTRIC SHOCK can kill.

•Do not touch live electrical parts

•Do not touch the weld output terminals when the contactor is energized.

•Do not touch electrode and work clamp at the same time.

IMPORTANT: To use the RHC-14 or RHC-23 contactor switch, the OUTPUT (CONTACTOR) switch on the welding power source must be in the Remote position for proper remote control operation.

The RHC-14 or RHC-23 switch has two positions, ON and OFF. Placing this switch in the ON position provides open-circuit voltage. Placing this switch in the OFF posi- tion stops open-circuit voltage (ocv goes to zero).

SECTION 4 − MAINTENANCE

WARNING: ELECTRIC SHOCK can kill; HOT SURFACES can cause severe burns.

• Do not touch live electrical parts.

•Disconnect plugs from power source before inspecting or servicing.

•Allow unit to cool before servicing.

Once a month inspect the Remote Hand Control cord for breaks in the insulating jacket particularly at the plug

and at the strain relief connector on the Remote Hand Control base. Repair all breaks with electrical tape, or replace the cord if necessary.

Daily, rotate the Remote Hand Control knob from the 0 to 100 percent position. This procedure will prevent oxi- dation from forming on the contacts, which could insu- late the contacts from the brush, causing the control to become inoperative. Refer to Table 2-1 for proper cord conductor size and to Diagrams 5-1 through 5-5 for proper cord conductor connections.

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