Failure of Single Conductor MV XLPE Cable at Joint

We have 4 individual circuits 3 single conductor cables per phase (4 circuits in all) in each cable the Shield and Armour are bonded at both ends to earth and the shields are run to Link boxes with Surge Voltage limiters (the connection here are in Wye)

We have three joints in the cable due to the long run (approx 1.5Km) two joints are simple typical MV joints with Armour and shield joined but separated from each other

The midpoint joint has the source end armour and shield bonded together and the load side similar bonded. These bonds are then run to a Link box conected in Wye

ie A B C from Source C B A to Load and all connected to earth

We are experie3nce serious heating at the armoured connection of the last joint, in fact the temperature is in excess of 110 C, we have two joints that have now failed.

We have circulating current flowing in all three bonds to earth at the load bonding connections (B C A) at the mid point Link Box

It is my belief that isolating the armour from earth at the load end (Transformer) will prevent this circulating current or at least reduce it to a minimum.