Hi Guys
I'm reviewing a MV cable installation design proposal and I'd appreciate some advice, scenario as below...
New Building with new MV switchgear being fed from an existing Main MV switchroom within the same facility campus.
MV distribution system is 20KV and there are 2 new supplies (A&B) to be installed to the new building.
New building total load is around 12,900 KVA and each supply must be able to accept full load.
Upstream breakers in Main MV switchroom are 1250A and the Incoming breakers in the new building MV switchroom are 630A.
The route between switch rooms is fully ducted (with cable chambers) and the distance is around 460m.
The current cable design is for 3x1c 185 AWA cables per circuit with AWA bonded at both ends and a separate 1c x 150mm CPC.
Cables to be installed in trefoil within ducts.
Current design has the MV terminations bonded at both ends
My question is; is double ended bonding suitable for this length of run or would there be potential issues with high circulating currents?
Regards, Seansasta
