By Frank Bertie NAPIT Group Technical Director - Question: During a refurbishment of a kitchen we came across copper sheathed cable supplying the accessories. The existing accessories have boxes with metal clamps which are securing the copper sheath cable terminations. The accessories are being relocated and we will have to alter these cables how do we do it or can we replace the cable with twin and earth cable?
Answer: The cable you mention is mineral insulated copper sheathed cable, which consists of normally two copper cores surrounded by a white compound material which acts as insulation, then a copper outer sheath to enclose the cores. Often this type of cable is then coated with an orange pvc sheath to prevent corrosion to the copper sheath.
There are different methods of terminating this type of cable, the one you mentioned is where the cable gland has not been utilised and only the pot/seal have been used, this type of cable requires experience and special tools to correctly terminate.
The cables can relocated but unless you have the necessary experience, it may require someone who is familiar with the cable and its terminations.
Normally when this type of cable is used in a domestic environment it is for a particular purpose, often in heritage style properties there is a requirement for fire rated wiring systems. You would have to check with the local authority or heritage department before making any alterations to the wiring system.