Ryobi MMA-140 Owner's Operating Manual page 16

Important: Ensure also that the earth clamp is
attached to clean, solid metal. If necessary
thoroughly clean with a wire brush or similar to
guarantee a good connection.
The earth clamp must only be connected to the
work piece. The area to be welded must be clean
and free from dirt, rust, paint, grease and oil.
Insert an electrode into the electrode holder (Fig.4)
ensuring there is a good connection.
Set the amperage (see Table 1) by adjusting the
regulator (Fig.5)(A) until the desired setting is
reached.
The chart below is an indicator of the electrode
diameter and the corresponding welding current.
This is intended as a guide only.
Table 1
Electrode Material
size (mm) thickness
(mm)
1.6 1 - 1.6
2.0 1.6 - 2.6
2.5 2.6 - 4.0
3.2 3.0 - 5.0
4.0 5.0 - 7.0
5.0 7.0 - 9.0
WARNING! Always wear a full welding
mask, welding gloves and protective
clothing. Wear goggles while chipping
slag.
Do not switch on the power supply until you are
ready to start welding. Practice welding on a piece
of scrap material.
Connect to the mains supply and press the On/Off
switch (Fig.6) to the ON position (l) The power
indicator lamp on the front panel (Fig.5)(B) will
illuminate. To stop the machine, press the On/Off
switch to the OFF position (0).
Note: If the machine stops at any time and the
thermal cut out indicator on the front panel
illuminates, the thermal cutout has intervened.
This indicator will turn on when the machine is
overheated and the output has been disabled. This
OPERATION
Welding
current (A)
25 - 40
40 - 70
60 - 100
80 - 130
130 - 170
170 - 200
normally occurs when the duty cycle of the
machine has been exceeded. Leave the machine
on to allow the internal components to cool. When
the indicator turns off, normal operation is again
possible.
16
Fig. 4
B
A
A
20 200
Fig. 5
Fig. 6