One of our electrical contractors did not advise the manufacturer of automatic transfer switches that 3 x 240mm single core cables where being connected to each of the phase and neutral terminals so the ATS was not manufactured to accommodate this. The contractor proposes to replace the bolts on L1, L2, L3 & N with a longer bolt to accept the cables.  

We asked for the contractor to confirm with the manufacturer of the ATSs that this was acceptable to them and received confirmation of same. However, the end user customer is not accepting this and has referred us to a British Standard that does not permit this. 

We are seeking your advice and position on this and look forward to hearing from you.