IEC 61439 is a standard developed by the International Electrotechnical Commission (IEC) that covers design verification for low-voltage electrical products and assemblies. To mount a bus bar to an assembly structure, hardware (studs, holes, etc. ) can be manufactured into the conductors. Mersen offers in-house conductor plating in tin. The purpose of this document is to detail the requirements of Northern Powergrid in relation to the tubular busbar systems and associated fittings detailed within this document. This document supersedes the following documents, all copies of which should be destroyed. Other sections have been updated and modified to reflect current practice.