General Information For Welding Transformer/Rectifier Operators - Metabo SK 200 MA Instrucciones De Servicio

Box 22 IP.. Degree of protection, e.g. IP21 or IP23.
Box 23 Symbol for protection class II, if applicable.

3.0 General Information For Welding Transformer/Rectifier Operators

Dust, dirt and metal chips will harm any welding machine. It is of particular importance that the air ventilation for cooling
is not obstructed.
A weld should join two work pieces as if they were made from a single piece. Prior to the welding the joints must be
cleaned and dirt, rust, grease and paint removed. Also slag from previous welds must be completely removed. Attach
earth clamp firmly to work piece, assuring good metal to metal contact. Check that all cables and connectors are in proper
operating condition to ensure proper current conduction.
Place electrode with the uncoated end into one of the electrode holder's notches. Each welding machine is supplied
complete with an accessory kit, which includes besides the welding cables a welding visor and a slag hammer. When
removing slag it is recommended to protect the eyes by suitable means (goggles) from injury by sharp and hot slag. The
welding visor's dark glass plate protects the eye against ultra-violet and infrared rays. The clear glass plate protects the
dark plate against spatters and damage. The dark protective glass is available in different shades for different types of
electrodes and to suit different eye sensivity. Normally for electrodes from 1.5 mm to 4 mm Ø protective glasses of shade
DIN 9 are used, for electrode over 4 mm Ø shade DIN 10.
Select the correct welding current as shown below:
In principle do not use too thick an electrode. As a general rule calculate 40 amps welding current per 1 mm of electrode
diameter. Depending on electrode type, material thickness and weld position this calculated value may have to be
adjusted to plus or minus.
All machines work well with thin plate from 1.0 mm thickness.
3.1 Care Of Stick Electrodes And Their Correct Use
In order to achieve a good weld the electrode has to be dry, thus storing in a dry place is essential- Should electrodes
have become moist, dry in an oven at between 200° C to 300° C for 30 minutes.
Basic coated low-hydrogen type electrodes always require pre-drying at 200° C to 300° C for 3 hours as atomic
hydrogen causes weld flaws.
Current (A) Electrode Ø
15 - 50 1.0 - 2.0 mm
50 - 100 2.0 - 2.5 mm
100 - 140 2.5 - 3.25 mm
140 - 220 3.25 - 5.0 mm
220 - 300 5.0 - 6.0 mm
Material Thickness
1.0 - 2.0 mm
2.0 - 4.0 mm
4.0 - 8.0 mm
8.0 - 12.0 mm
12.0 - 20.0 mm