Lincoln Electric DC-400 Power Source Operation, Duty Cycle and Time Period, Duty Cycle Amps Volts

B-6 OPERATION B-6

POWER SOURCE OPERATION

WARNING

ELECTRIC SHOCK can kill.

•Have an electrician install and service this equipment.

•Turn the input power off at the fuse box before working on equipment.

•Do not touch electrically hot parts.

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Duty Cycle and Time Period

The DC-400 is rated at the following duty cycles:

DUTY CYCLE *	AMPS	VOLTS
100%	400	36
60%	450	38
50%	500	40

*Based upon 10 minute time period (i.e., for 60% duty cycle, it is 6 minutes on and 4 minutes off).

Overloading the DC-400 may result in opening of an internal protective thermostat as indicated by the amber thermal protection light turning on.

STARTING THE MACHINE

The POWER toggle switch at the extreme right side of the control panel in the “I“ position energizes and clos- es the three phase input contactor from a 115 volt auxiliary transformer. This in turn energizes the main power transformer.

The machine is de-energized when the POWER switch is in the “0” position.

The white light below the POWER switch indicates when the input contactor is energized.

OUTPUT CONTROL DIAL

The OUTPUT control to the right of the center of the control panel is a continuous control of the machine output. The control may be rotated from minimum to maximum while under load to adjust the machine out- put.

The machine is equipped with line voltage compensa- tion as a standard feature. This will hold the output constant except at maximum output of the machine, through a fluctuation of ±10% input line voltage.

OUTPUT CONTROL “LOCAL-REMOTE” SWITCH©

The OUTPUT CONTROL toggle switch on the control panel labeled “LOCAL-REMOTE” gives the operator the option of controlling the output at the machine control panel or at a remote station. For remote con- trol, the toggle switch is set in the “REMOTE” position and controlled at the wire feed unit control, or by con- necting a K775 control to terminals 75, 76, and 77 on the terminal strip at the front of the machine, or by connecting a K857 control to the 14-pin connector on the front of the machine. For control at the machine control panel, the toggle switch is set in the “LOCAL”.

(Exception: When used with an LN-9, LN-9 GMA or NA-5 wire feeder, the OUTPUT CONTROL switch must be in the “REMOTE” position or automatic shut- down of the LN-9 or NA-5 may occur.)

POLARITY SELECTION

Polarity selection is made by appropriately connecting the electrode and work welding cables to either the “+” stud or to the “-” stud. Select “VOLTMETER” switch for “+” or “-” electrode for the remote (#21) work sensing lead.

VOLTMETER SWITCH

Select “+” for positive electrode or “-” for negative electrode polarity for the remote (#21) work sensing lead of automatic or semiautomatic equipment.

THERMAL PROTECTION LIGHT

The amber thermal protection light will be lit if either of the two protective thermostats have opened. The out- put power will be disabled but input power will still be applied to the welder. (Refer to Machine and Circuit Protection section).

MODE SWITCH

The large MODE SWITCH on the left side of the machine, labeled “Constant Voltage (Submerged Arc), Constant Voltage (FCAW/GMAW) and Constant Current (Stick/TIG)”, is used to select the proper welder characteristics for the process being used.

The CV (FCAW/GMAW) Mode permits the DC-400 to produce essentially a flat output characteristic that can be varied from approximately. 12 to 42 volts.

DC-400