Welding Cables on Longwall Faces
Welding cables may be installed along a longwall face. One location (approximately No. 15 shield) may be designated as the normal welding location. Open type connectors may be installed at the normal welding location. These open type connectors shall only be installed in-line in the cable and not installed as a tap. The open type connectors shall be of the locking type that provides a dependable mechanical connection that assures that the connector will not separate.
All other locations on the cable, other than the normal welding location, shall be spliced with only compression type connectors. When splicing the welder cable, either with the open type connector at the normal welding location or with compression type connectors at all other locations, the conductors must be insulated and the cable jacketed using an MSHA approved splice kit. No more than five splices, including the open type connector splice at the normal welding location, shall be installed in the cable. After the fifth such splice is made, the cable shall be changed before the welder is used on the following shift. When welding at the normal welding location, or any other location across the face, open type connectors may be used only at the active welding location.
The welding cable must be cut at the welding location leaving the remainder of the cable along the longwall face disconnected and de-energized during the welding operation. At no time shall the welding cable insulation be skinned in order to clamp onto the welding cable with a tap to the welding location. The welding cable along the longwall face shall be terminated in an XP enclosure at the tailgate end of the cable. It has been determined through engineering analysis and consultation with welder manufacturers that the resistance of welding cable, due to long lengths, does not affect the safety of the welder. However, the size of the cable must be capable of carrying the expected welding current.
Due to the lack of visibility of the welding cable in the trough, a record of each splice location shall be maintained at the mine.