IMA 551C
500AS
Page 7
For normal running, lubricating and maintenance instructions,
consult the engine instruction manual. For correct cooling air flow,
the welder should be operated with the doors closed.
GENERAL
Connect the electrode and ground cables to the studs marked on
the welder output panel. The studs are marked Electrode and
Work. Some types of electrode require electrode positive and
others negative. Therefore consult the instructions for the
particular electrode being used to determine which polarity to use.
When welding at a considerable distance from the machine, care
should be taken that ample size welding cables are used. Small
size cables for long distances reduce the output at the point of
welding.
After the welder has been in operation for some time, all internal
and external connections should be checked to make certain they
are tight.
Cylinder head nuts must be pulled down after 25 hours operation
and no later - see Engine Manual.
SETTING THE CONTROLS
The welder is equipped with Dual Continuous Control of the
welding output. To meet the varied requirements of present-day
welding it is highly desirable to be able to vary the voltage and
current separately. Dual Continuous Control means that it is
possible to get the proper welding current throughout the range of
the machine in two or more ways.
There are two controls which determine the output of the
generator:
1.
Continuous Current Control - to vary the welding
amperage.
2.
Job Selector - to vary the open circuit voltage of the
generator.
JOB SELECTOR
The Job Selector is both the fine current adjustment and the
voltage control of the welder. With this control it is possible to
obtain the exact current necessary. Also, by means of this control
the open circuit voltage can be varied to suit different welding
applications.
The Job Selector is divided into four sections. The section marked
“Large Electrodes” provides a high open circuit voltage. The
section marked “Normal Welding Range” gives a medium high
open circuit voltage. The section marked “Overhead and Vertical”
gives a medium low open circuit voltage. The section marked
“Special Applications” provides a low open circuit voltage and is
used with a minimum setting on the Continuous Current Control.
CONTINUOUS CURRENT CONTROL
The Current Control provides the major adjustment of welding
current to suit any particular application. The dial reads
continuously in a clockwise direction from maximum to minimum
and has three graduated concentric dials corresponding to the
respective sections of the Job Selector dial. When the Job
Selector is set on the “overhead and vertical” section of its dial,
the approximate welding current is indicated by the “overhead and
vertical” scale on the Current Control dial.
Do not change the current control setting while welding.
HOW TO SET THE CONTROLS
Assume you want to make a vertical up weld using a 4.0mm
electrode at about 135 amps. A snappy digging arc (medium low
open circuit voltage) is required to give the best control of the arc
in the whipping technique that must be used.
1.
Set the Job Selector to the section of the dial marked
“Overhead and Vertical”.
2.
Set the Current Control to read 135 amps on the scale
marked “Overhead and Vertical”.
3.
Strike the arc.
4.
If the arc is too weak, move the Job Selector counter-
clockwise to increase the current. If a still higher current is
desired, turn up the Current Control 10 or 20 amps. In the
final adjustment, be sure the Job Selector is still set in the
same range to get the snappy arc recommended for
vertical welding.
AUXILIARY POWER
These machines are fitted with two standard 3 pin, 240 volt, 10
amp auxiliary power outlets, and two 3 pin, 115 volt auxiliary
power outlets. Full auxiliary power is available while welding up
to rated output (475 amp, 40 volt). The outlets are located on the
control panel of the 500 AS. Total power available is 4,000 watts,
240 volt, 60 Hz. A.C. at unity power factor, or 3,200 watts at 0.8
power factor and 100% duty cycle.
Both 240 volt and 115 volt supplies can be used simultaneously,
provided the total current drawn does not exceed 16.5 amps
and/or 4,000 watts as above.
Important - The 500AS auxiliary power circuits are not connected
to the welder frame, and earth leakage protection is not required
(Refer AS2790 - 1989, Cl 6.1.9 (a) and Comment 1), however
connected equipment should be double insulated, or fitted with an
effective earth wire.
USE OF WELDERS AS STAND-BY POWER UNITS
Welders with 240 volt auxiliary A.C. outputs can be used as stand-
by power units.
To avoid the possibility of electric shock and/or damage to the
welding machine, connections and alterations must be made by a
licensed electrician, who can determine suitability and how the
machine can be adapted to the particular installation and comply
with the local Supply Authority regulations.
It is also essential that an adequately rated isolation switch is
used to ensure that the stand-by power unit and the Authority’s
Supply are not connected in parallel.
The 500AS is suitable for temporary, stand-by or emergency
power using engine manufacturer’s recommended maintenance
schedule. Not recommended for long term primary power.
Not withstanding the above, should a Residual Current
Device (RCD) be fitted to this machine, it is imperative that
the frame of the machine be earthed in accordance with
AS3000, Clause 5.6. An effective earth is essential for the
safe operation of machines fitted with RCD devices.
WARNING
Summary of Contents for SHIELD-ARC 500AS
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