VT Cable Size

Guest,

I will presume you are asking about the 115v side of the VT since you mention a 'fuse box'.

That being the case, the 115v is used for metering, relays and other controls. This is not a power circuit that will draw very much current.

The normal conductor size for this will be #12cu stranded THW. If it may possibly be subjected to oils and gasoline etc, use THHN insulated wire, and pull it carefully so as not to break the outer nylon shell.

In regard to the word "standard", that is determined by the local power authority. If that is you, then confidently go with the answer above.

Dear Sir,

For The VT secondary the standard size being 2.5 sq.mm multistrand copper wire, irrespective of the core is used for metering or protection circuit.

Best Regards,

N.Suresh

I understand that VT burden is required to know before selecting cable size. Go through VT sizing calculation process refer IEC 60044 Part 1 & 2 you will do the cable sizing correctly. Regarding insulation selection its the location where VT will be installed. In case of Hazardous area, use FRLS cable, THHN group of insulation also can be used. Some local practice and client's requirements also emphasise on the selection.

British Standard 7671.