Mma Welding Guide - Parweld XTI 200 AC/DC P Instructions For Use Manual

16) Pulse selector. Switches DC pulsing on or off when
in DC TIG welding mode.
17) Process selector switch Switches the machine
between TIG welding and MMA welding mode. Note:
the power output is latched on when in MMA mode
so it should only be changed over when all output
cable connections have been made to the machine.
18 19
18) Negative Power output terminal
19) TIG Welding gas output (3/8 BSP)
20) Trigger socket This is the connection point for the
torch trigger which starts and stops the welding cycle
when in TIG welding mode. This is also the
connection for the remote foot control or torch
mounted remote control.
5
4
0
22) Positive Power connection
Connection of torches and operation
Wide safety margins provided by the coil design ensure that
the welding power source will withstand short-term overload
without adverse effects.
The welding current range values should be used as a guide
only. Current delivered to the arc is dependent on the welding
arc voltage, and the process selected. The operator should
use the welding current range values as a guide, and finally
adjust the current setting to suit the application.
CAUTION:
Before connecting torch and cables to the machine make sure
the primary power supply is switched off. Remove any
packaging material prior to use. Do not block the air vents at
the front or rear or sides of the welding power source.
MMA cable connections
Connect work lead to Negative terminal
Connect electrode lead to the Positive terminal 6 insert an
electrode in the holder. Ensure the selector switches are in
the following positions MMA, Pulsing off and select AC or DC
depending upon the electrode type. Switch the machine on.
Use the control knob to adjust the require output current.
XTI 200
AC/DC
20 22
1
2
3
10k

MMA WELDING GUIDE

Electrode polarity
MMA electrodes are generally connected to the torch terminal
and the work lead to the work piece terminal
But if in doubt consult the electrode manufacturer's literature.
Effects of stick welding various materials
High tensile and alloy steels
The two most prominent effects of welding these steels are
the formation of a hardened zone in the weld area, and, if
suitable precautions are not taken, the occurrence in this zone
of under-bead cracks. Hardened zone and under-bead cracks
in the weld area may be reduced by using the correct
electrodes, preheating, using higher current settings, using
larger electrodes sizes, short runs for larger electrode
deposits or tempering in a furnace.
Manganese steels
The effect on manganese steel of slow cooling from high
temperatures enbrittlement For this reason it is absolutely
essential to keep manganese steel cool during welding by
quenching after each weld or skip welding to distribute the
heat.
Cast iron
Most types of cast iron, except white iron, are weldable. White
iron, because of its extreme brittleness, generally cracks when
attempts are made to weld it. Trouble may also be
experienced when welding white-heart malleable, due to the
porosity caused by gas held in this type of iron.
Copper and alloys
The most important factor is the high rate of heat conductivity
of copper, making preheating of heavy sections necessary to
give proper fusion of weld and base metal.
Types of electrodes
Arc welding electrodes are classified into a number of groups
depending on their applications. There are a great number of
electrodes used for specialized industrial purposes which are
not of particular interest for everyday general work. These
include some low hydrogen types for high tensile steel,
cellulose types for welding large diameter pipes, etc. The
range of electrodes dealt with in this publication will cover the
vast majority of applications likely to be encountered; are all
easy to use and all will work on even the most basic of
welding machines.
Metals being joined & electrode comments
Mild steel
6013 ideal electrodes for all general purpose work. Features
include outstanding operator appeal, easy arc starting and low
spatter.
Mild steel
7014 all positional electrode for use on mild and galvanized
steel furniture, plates, fences, gates, pipes and tanks etc.
Especially suitable for vertical down welding.
Cast iron
99% nickel suitable for joining all cast irons except white cast
iron.
Stainless steel
318l-16 high corrosion resistance. Ideal for dairy work, etc. On
stainless steels.