9
Preparation
-3
for Operation
Make sure that the connector fits in its socket safely without tightening too much. Otherwise, in long time
usages and in cases where the welding current is high, loosen connectors may burn due to overheating.
For electrodes to be used in DC (-), change cable connections as electrode cable to (-) outlet (5) and
grounding clamp to (+) outlet (4). Choosing wrong pole causes unstable arc creation, too much splashing
and electrode to stick on work piece.
2 - Install electrode to electrode clamp.
3 - Connect work clamp to the surface of the work piece which is unpainted, rustless and clean as its ends
contact completely.
4 - Insert mains connection cable to suitable plug.
5 - Before starting to welding operation, perform the following checks:
a - Make sure that the welding machine is grounded safely.
b - Make sure that all contact surfaces, especially the connection between clamp on the tip of work
cable and work piece are performed firmly.
c - Check whether welding cables connected correctly.
d - Splashed pieces and sparks during welding operation may cause fire. Therefore pay attention not
to keep flammable material within the area where welding operation is performed.
6 - Turn on the On/Off switch (9).
7- Adjust suitable welding current value which will be determined according to electrode diameter, type,
welding position and electrode information sheet, with “Welding Current Adjusting Knob (2)”. Generally
welding current is between the specified values. It is useful to adjust welding current according to the
values specified in catalog of manufacturer company of the shielded welding electrode.
Expressweld Inverter 251-Ultra is a descending characterized welding machine for melting stick
welding electrodes in 2.5 and 4.0 mm diameter having rutile and basic characterized shielding.
Current Values for Rutile and Basic Electrodes:
0 2.5 mm : 70 - 100A
0 3.2 mm : 100 - 140A
0 4.0 mm : 140 - 190A
You can check the adjusted welding current value by observing from the digital indicator located on the front
panel, when necessary you can fine tune according to welding situation.
8 - Start welding by following welding rules.
