Overload Protection; Auxiliary Power - Lincoln Electric IDEALARC SVM 122-A Service Manual

B-9
LN-7 AND LN-9 SEMIAUTOMATIC WIRE FEEDERS
OR OTHER CONSTANT SPEED WIRE FEEDERS
To use the LN-7, LN-9, or other constant wire feed
speed semiautomatic wire feeders with the Idealarc
DC-400:
1. Set the Idealarc DC-400 welding MODE switch to
either CV FCAW/GMAW mode or CV Submerged
Arc mode, depending on the welding process
being used.
NOTE: These semiautomatic wire feeders cannot
be used in the CC mode.
2. Set the Idealarc DC-400 OUTPUT CONTROL
switch.
a. LN-7: Use either an optional K775 Remote
Control Box Assembly or set the Idealarc DC-
400 OUTPUT CONTROL switch in the "Local"
position.
b. LN-9: Refer to the LN-9 Operator's Manual for
instructions on how to use the LN-9.
c. LN-25: Refer to the LN-25 Operator's Manual
for instructions on how to use the LN-25.
d. LN-742: Refer to the LN-742 Operator's
Manual for instructions on how to use the LN-
742.
OPERATION

OVERLOAD PROTECTION

The power source is thermostatically protected with
proximity thermostats against overloads or insufficient
cooling. One thermostat is located on the nose of the
center bottom primary coil. A second thermostat is
attached to the lead connecting the secondaries. If the
machine is overloaded, the primary thermostat opens,
the output becomes zero, and the amber thermal pro-
tection light comes on. The fan will continue to run.
The secondary thermostat opens with either an exces-
sive overload or insufficient cooling. The output
becomes zero, and the amber thermal protection light
comes on. When the machine cools, the thermostats
reset, and the thermal protection light goes off.
The power source is also protected against overloads
on the SCR bridge asssembly through an electronic
protection circuit. This circuit senses an overload on
the power source and limits the output to 550 amps by
phasing back the SCRs.
The Idealarc DC-400 also has self-restoring fusing to
prevent damage to the machine in the event of an
accidental grounding of the remote control leads (#75,
#76 or #77).

AUXILIARY POWER

The Idealarc DC-400 can provide nominally 115 volt
AC and 42 volt AC auxiliary power for operating wire
feeding equipment and other accessories. This power
is available at the 14-pin amphenol on the control
panel and/or at the terminal strip behind the hinged
control panel on the case front. On the amphenol, 115
volts AC is available at pins A and J (Domestic and
Export models only); 42 volts AC is available at pins I
and K. On the terminal strip, 115 volts AC is available
at terminals 31 and 32; 42 volts AC is not available.
The two circuits, 115 volts AC and 42 volts AC, are iso-
lated; and each is protected by a 10 amp circuit break-
er.
On European and export models, a Continental
European receptacle is provided on the rear panel for
supplying 220 volts AC to a water cooler. A 2 amp cir-
cuit breaker, also located on the rear panel, protects
this circuit from overloads or short circuits.
IDEALARC DC-400
LINCOLN
®
ELECTRIC
B-9