INTRODUCTION
The Arc Welding Set, Model SA-136 is designed for consumable
electrode inert-gas shielding welding. It incorporates a well-balanced
handgun and a control with a built-in contactor. The system is designed
for semi-automatic welding of aluminum with aluminum wire sizes from .030
to 3/64 inch diameters. It is rated 200 amperes continuous duty and is
air-cooled. (Numbers in parentheses indicate item numbers on referenced
drawings.)
DESCRIPTION
Control Monitor
The Control Monitor as shown on
is light weight,
fully insulated, and compact.
The Control Monitor operates from a 115 volt A.C. or D.C. power supply
which is necessary for the operation of the control and inching circuits.
The power for the gear-head drive motor during the welding operation is
supplied by the welding machine. The motor armature is said to be "across
the arc". This is accomplished by attaching the terminal of the ground
cable (4) to the negative lug of the welder and the terminal of the current
cable (12) to the positive lug of the welder.
A rheostat (1) in series with the motor armature is adjusted to control the
wire feed speed and the arc length. The rheostat setting will vary with
different welding machines and is dependent on the current setting of the
welder. The fact that the wire feed drive operates from the arc voltage is
important, because it insures good steady feeding consistent with constant
arc length. It is based on the following principle of operation: If the
arc length increases, the voltage across the arc becomes higher, and as a
result the motor speed increases thereby feeding more wire and shortening
the arc length. If the arc length shortens, the voltage across it is lower
and the motor speed decreases thereby increasing the arc length. The rheo-
stat type control will permit approximately a 2 to 1 speed adjustment.
An "On-Off" switch (2) energizes the control monitor while renewable fuses
(6) protect the line. The power supply cord (3) is a 16 foot cable termi-
nated in a three-prong plug with a three to two wire plug adaptor. A
replaceable fuse (7) in series with the wire drive motor protects the arma-
ture from damage due to high current. This is a one ampere fuse and should
not be replaced with a larger fuse. The use of a larger than recommended
fuse automatically voids the warranty on this equipment. The line fuses (6)
should be 2 ampere fuses.
The Control Monitor has a current relay which permits touch starts. The
minimum current required to operate the relay is approximately 45 amperes.
A 200 ampere D.C. contactor (9) is mounted in the control enclosure and is
controlled from the control panel (8).
