Miller Electric OM-842 Smaw Mode, Weld/Peak Initial Current B Final Slope Slope, Preflow Postflow

Not separate steps.

Current level controlled by remote amperage control.

Weld/Peak

Initial Current B Final

Slope Slope

Initial	Final
Current	Current
Preflow	Postflow

A

A:Momentary closure of Start/Increase push button starts sequence.

B:Momentary closure of Start/Increase push button ends weld/peak cur- rent.

Preflow: Time programmed/Volume set by gas meter.

Start Level (Not Shown): Time & level programmed.

Initial Current: Time & level programmed.

Initial Slope: Time programmed/Slope calculated by microprocessor control.

Weld/Peak Current: Time undefined/Level programmed.

Final Slope: Time programmed/Slope calculated by microprocessor control.

Final Current: Time & level programmed.

Postflow: Time programmed/Volume set by gas meter.

Weld/peak current cannot be increased or decreased during welding.

Stop push button is not functional throughout sequence.

In this mode, a single momentary closure of the Start/Increase push button starts the sequence. The pro- gram continues through the pro- grammed sequence of events until weld/peak current. The operator presses the Start/Increase push but- ton to signal the end of weld/peak current, at which time final slope starts.

The weld amperage cannot be in- creased or decreased once the se- quence has started, and the Stop push button is not functional. Post- flow starts if the arc is manually broken.

Ref. SB-139 983

Figure 4-5. Semi-Automatic 5 Mode Sequence

C. Manual GTAW Mode Sequence

	Initial	Weld/Peak	Final
		Current
	Slope		Slope
	Initial		Final
B	Current		Current
Preflow			C Postflow

A

A:Closure of remote contactor control starts sequence.

B:Arc ignition starts initial current.

C:Opening of remote contactor control starts postflow.

Preflow: Time programmed/Volume set by gas meter.

Start Level (Not Shown): Time & level programmed.

Initial Current: Time undefined/Level programmed.

Initial Slope:

Weld/Peak Current:

Final Slope:

Final Current:

Postflow: Time programmed/Volume set by gas meter.

Remote Pendant not used.

Weld/peak current can be increased or decreased during welding.

A Manual GTAW program requires the operator to perform most of the control of the welding process. This is carried out through the use of a re- mote control providing contactor and amperage control (not the Remote Pendant). High frequency is avail- able for non-contact weld starts.

Preflow starts when the remote con- tactor control is closed. Following arc ignition, the weld sequence en- ters initial current. Once initial cur- rent starts, the operator controls the output level through the use of the remote amperage control. The maxi- mum output that can be commanded is defined when the program is created. The minimum value that can be commanded is the defined initial current level. Postflow starts when the remote contactor control is opened.

Ref. SB-139 983

D. SMAW Mode

A program entered in the SMAW mode does not follow the weld sequence shown in Section 4-2. On/Off control of the welding power source contactor is accomplished through a remote contactor control, and arc initiation and extinguishing are done manually. Weld output can be controlled remotely or kept at a defined level, depending on programmed parameters. If remote control is used, the maximum output that can be commanded is defined when the program is created. The minimum is the minimum output the welding power source is capable of.

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