The basic application of current transformers are :
Lowering the very high primary current passing through bus bars, cables, or wires to 5A or 1A. A measurable quantity by measuring instruments. Isolating the measuring instrument and protective devices from mains. Reproduces proportionate primary current on its secondary side required for extending the range of the instruments.

Basically CTS are of different types :
BAR PRIMARY CURRENT TRANSFORMER (BPCT) For Current of 100A and above the bus bars or cables are quite thick and it is easier to measure the currents without breaking the bus bars or cable by means of Bar Primary current transformer which can be slipped over the bus bar or cable. These CTs are most commonly used as they are study compact and cheaper.
WOUND PRIMARY CURRENT TRANSFORMER (WPCT) For current below 100A, it is uneconomical to achieve the desired accuracy by making CT Bar primary type and the solution is Wound Primary C.T., where both primary and secondary are Wound over the core.
CLAMP ON CT'S NIPPEN clamp on CT's enable quick and accurate current measurements on live circuits without disconnecting loads. Precision phase shift characteristics ensure accurate power on energy measurements conveniently. These form one of the accessories in our energy audit system.
Three Models are available : Model Range Accuracy Burden Cond.Size NE1 100/1A 1% 1 Ohms ø 15mm NE2 1000/5A 2% 20 Ohms ø 53mm NE3 3000/5A 2% 20 Ohms ø 70mm

Analog Meters

MI & MC Meters

Bimetallic Meter

Frequency Meters

Phase Sequen. Meters

Insulation Testers

Earth Testers

Transducers

Digital Meters

DM Series

Insulation Testers

Electron. Energy Meter

VAF Meter

Multi ParaMeter

Multi Meter

Clamp Meter

SLM

Smart Load Manager

EAM

Energy Audit Master

ENERG.MGT.SYS

Energy Mgt. System

ACCESSORIES

Shunts

Current Transformer