Section I. GENERAL
Form 2028. Submit recommendations for changes,
additions, or deletions to the Commanding Officer, U.
S. Army Mobility Support Center, ATTN: SMOMS-MM,
a. These instructions are published for the use of
P. O. Box 119, Columbus, Ohio 43216. Direct
personnel to whom the Model LA-300 Arc Welding
communication is authorized.
Machine is issued. The instructions contained herein
provide information on the operation, lubrication,
e. Report unsatisfactory equipment performance
maintenance, and overhaul procedures for the
and suggestions for equipment improvement to the
organizational unit for initiating necessary corrective
2. Record and Report Forms
Maintenance Allocation Chart which lists the
DA Form 2258
Maintenance and Repair Operations authorized for all
echelons of responsibility and shall be strictly adhered
For other record and report forms applicable to The
c. Numbers in parentheses on the illustrations
Operator, Crew, and Organizational Maintenance refer
indicate quantity. Numbers preceding nomenclature
to TM 38750.
callouts on illustrations indicate the preferred
Note. Applicable forms excluding standard Form 46
d. Report all deficiencies in this manual on DA
which is carried by the operator, shall be kept in a
canvas bag mounted on the equipment.
Section II. DESCRIPTION AND DATA
frame, gives protection against burn-out of the motor
from all usual causes. Protection is assured against
burn-out if the windings reach a maximum safe
a. General. The welding machine (fig. 1 and 2)
operating temperature from any cause too frequent
Model LA-300, is a self-contained, trailer mounted,
overloads, high room temperature plus overload,
semi-enclosed unit and is, excluding the controls,
abnormally high or low voltage, or abnormally high
The welding machine is
current due to single phase or unbalanced phase
equipped with the necessary controls, instruments, and
conditions. The thermostats automatically reset when
accessories for operation. All accessories and controls
the motor returns to a safe temperature and no manual
which are mounted on top of the welding machine are
operations are required to restart the machine except
readily accessible. The unit is equipped with one towing
pushing the start button.
arm attached to one end and a lifting eye located on top
of the machine.
c. Control Panel.
contains all the switches and indicators necessary for
b. Motor-Generator. The motor-generator is an
the operation of the unit. Included in this group are the
electric A.C. unit with a D.C. output made by Lincoln
job selector, current control, remote switch, current volt-
Electric Co. The unit is rated at a nominal 300 amperes
amp meter, circuit breaker and polarity switch. Also
at 40 volts while operating at a 60 percent duty cycle.
on the control panel is the push-button
The A.C. motor is protected by a special protective
device operated by both temperature and current. This
thermostats mounted on the laminations of the motor