Power Source Connection Diagrams - Lincoln Electric NA-3 Service Manual

A-9
5. Connect the two electrode cables of
the input cable assembly to the left
side (when facing the front of the
control box) of the current transformer
assembly located on the back of the
control box.
6. Insert the polarized connector of the
control cable into the matching
receptacle on the side of the control
box.
NOTE:
precautions to avoid possible erroneous
meter readings due to induced voltages or
magnetic fields caused by the current
flowing in the weld cables.
When welding with more than one AC arc,
space all control cables at least 12 in.
(305 mm) from all weld cables.
On critical applications, to reduce arc voltage
change and to keep meter discrepancy to a
minimum, disconnect lead #21 on the control
cable from the power source terminal strip.
Extend lead #21 so it can be connected
directly to the work piece. Remove lead #67
from the NA-4 connection bar. Extend and
INSTALLATION
Obey special cable
a. Separate the K215 input control
cable assembly so the control
cable is kept spaced from the
weld cables by at least 12 in.
(305 mm) to avoid induced
voltages.
b. Route the weld cables into the
control box on the opposite side
from the control cable connector
to avoid magnetic field influence
on the control box meters.
NA-3 AND NA-4
connect lead #67 directly to the electrode
contact assembly on the head. Use
#16 AWG conductors and keep leads #21
and #67 as far as possible from electrode
and work leads.
115 volt AC power to drive the standard
Lincoln travel carriage or for starting and
stopping other travel mechanisms is
obtained from a receptacle on the control
box. The travel receptacle has been
changed on NA-3 and NA-4 controls above
routing
code 8300. The 3-slot receptacle has been
replaced with a 4-socket receptacle which
provides a grounding lead connection for
TC-3 carriage travel controls.
POWER SOURCE
CONNECTION DIAGRAMS
The following section contains the wiring
diagrams necessary to connect the
applicable power source to the control box.
If it is not a Lincoln Electric power source,
refer to Figure A.19 at the end of this
section.
A-9
WARNING
ELECTRIC SHOCK
can kill
• Turn off input power to
the welding power
source using the
disconnect switch
before working on this
equipment.