Page 364 of 561

ELECTRODE WELDING AND GOUGING Electrode holders, Cable connectors and return clamp assemblies Cable connectors and return clamps are important – but often neglected – parts of the welding current circuit. The voltage drop in a poor or a wrongly positioned return clamp can be considerable, equal to many meters of additional cable, and the welding arc will suffer accordingly (see section on voltage drop in welding cable).

The Electrode holders

Unitor’s fully insulated electrode holders are of the lever screw type and feature an especially robust and safe clamping arrangement for the electrodes. The holders are of strong and simple construction. There are three types of electrode holder available, the 200A, 400A and 600 A.

The return connection

The return connector must be sufficiently dimensioned to provide good contact for the welding current load to be used. The positioning of the return clamp determines how large a

part of the vessel or of the work piece

is to be utilized as part of the welding current circuit. The return clamp should always be placed as close as possible to the welding area, or on the work piece itself if this is not an integral part of the hull. The thickness of material between welding point and return clamp must be sufficient to carry the current load that is to be used. Think carefully before fixing the return clamp so that sensitive machine

parts such as ball bearings etc. are not used as a bridge for welding current.

The Cable connectors

Cable connectors must be insulated in such a way that the danger of handling or short-circuiting through the deck is reduced to a minimum. This applies both to connected and unconnected parts. There should be no possibility of short-circuiting in connected plugs and sockets attached to cables, even if they should come into occasional contact with salt water. There must be good contact and little resistance at the contact areas and at the welding cable connections to the connectors. Unitor Safety cable connectors meet these requirements, more than 1400 mm2 contact area ensuring good contact between plug and socket, and when carefully assembled, the connectors are as good as watertight against spray and when decks are sporadically washed. The connectors may be used on cable dimensions from 35 mm2 up to 95 mm2 and are designed to accept up to 750 A welding current.

Dix quick-action connectors are used for front panel connections on the welding machines. These provide easy polarity changes, but are not fully insulated and are therefore not recommended as cable connectors for cable extensions along open deck. Adapters for connection to Unitor Safety connectors are available.

4.01

363