GENERAL MACHINE DESCRIPTION
The DC-400 is an SCR controlled three phase DC power
source. It is designed with a single range potentiometer
control.
RECOMMENDED PROCESSES
& EQUIPMENT
The DC-400 model is designed for all open arc processes
including Innershield
®
and all solid wire and gas procedures
within the capacity of the machine, plus the capability of
stick and TIG welding and air arc gouging up to 8mm
diameter. A mode switch selects CV (FCAW, GMAW), CV
Submerged Arc, or CC (Stick/TIG).
Stick welding
performance is similar to that of the R3R-500.
The DC-400 is designed to be used with the LN-7, LN-7
GMA, LN-8, LN-9, LN-9 GMA, LN-21. LN-22, LN-23P, LN-
25, or LN-742 semiautomatic wire feeders, the NA-3,.NA-5
and NA-5R automatics, and the LT-56 and LT-7 tractors,
within the 400 ampere capacity of the machine. The DC-
400 Diode Kit option is required to utilise the cold start and
cold electrode sensing features of the NA-3, NA-5 and NA-
5R.
DESIGN SUMMARY
Operational Features & Controls
ARC CHARACTERISTICS
Through the unique combination of the transformer, three
phase semiconverter rectifier, capacitor bank, arc control
choke, and the solid state control system, outstanding arc
characteristics are achieved on constant voltage.
In addition, an arc force control enables the DC-400 to stick
weld as well as the R3R-500.
OUTPUT CONTROL
The OUTPUT control, a small 2 watt potentiometer, is
calibrated from 1 to 10. The OUTPUT control serves as a
voltage control in the CV position and a current control in
the CC position.
MACHINE OUTPUT CONTROL SWITCH
“LOCAL”OR “REMOTE”
The machine output can be controlled by either the
OUTPUT control on the machine control panel, the output
control on the wire feed unit, or an optional “remote control”
that is available. This switch selects the mode of control,
either “LOCAL” or “REMOTE”.
OUTPUT TERMINALS “ON” OR OUTPUT
TERMINALS “REMOTE”
This switch provides an alternative to the “2 to 4” jumpering
function by energising the machine’s output regardless of
whether “2 or 4” is jumpered or not.
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 “+” ELECTRODE OR “-”
ELECTRODE
This switch selects electrode polarity for the remote (#21)
work sensing lead of automatic or semiautomatic
equipment.
POWER SWITCH
The power input contactor operates from an auxiliary 115
volt transformer that is energised through the POWER
toggle switch on the machine control panel. “ I “ is on and
“0” is off.
PILOT LIGHT
A white light on the machine control panel indicates when
the power source input contactor is closed. This means the
main power transformer and all auxiliary and control
transformers are energised.
THERMAL PROTECTION LIGHT
An amber light on the machine control panel indicates
when either of the two protective thermostats has opened.
Output power will be removed but input power will still be
applied to the machine.
INPUT CONTACTOR
The power source is equipped with an input contactor.
AUXILIARY POWER CONNECTIONS
The power source is equipped to furnish nominally110-115
volt AC and 40-42 volt AC auxiliary power for operating wire
feeding equipment, etc. The auxiliary power is available at
the 14-pin MS-style connector receptacle on the control
panel and/or at a terminal strip behind the hinged control
panel on the front of the power source. 110-115V AC is
available at receptacle pins A and J and terminals 31 and
32. 40-42V AC is available only at receptacle pins I and K.
The 110-115V AC and the 40-42V AC are isolated circuits
and each is protected by a 10 amp circuit breaker.
REMOTE CONTROL CONNECTIONS
Remote control connections are available both at a 14-pin
connector receptacle located on the control panel, and on
terminal strips with screw connections located behind the
hinged control panel on the front of the power source.
OUTPUT CONNECTIONS
The output terminals are recessed on the case front and
labelled “+” and “-”.
INPUT CONNECTIONS
The three input lines are brought in through the rear panel
of the power source and attached to the input contactor.
Removal of the removable access panel makes the
contactor accessible for the input cable connections.
Page 10
DC-400
IMA 474
ARC WELDING SUPPLIES - 07 847 7870
