Do you wish to know the diameter because you need to pass something of a certain size through a CT?

Thank so much for your replying

Some of information is as follows.

Application: 7.2Kv medium voltage motor starter

Location of installation: outgoing cable

Cable Size: XLPE (N2XSY) 1×70mm▫

Out side diameter of cable: 30mm

Core balance ratio:

Primary: 50A

Secondary: 1 A

Max. Temperature: 40°

Kindest Regard

A.HOSSEINI

Application: 7.2Kv medium voltage motor starter

Do you mean 7.2kW or is it 7200 volts?

Yes, the voltage level is 7200 volt

There are 2 configurations of how the cable can pass through the CT;

1. side-by-side (in a line) &,

1. in trefoil (a triangular formation).

Decide which configuration you want & then calculate the external limits of the cable group.

A side-by-side configuration will require a rectangular slot in the CT & a trefoil configuration will require a circular hole in the CT.

Iwant used a trefoil configuration by circular hole.