JK-G / JKS-G

CURRENT TRANSFORMERS | OUTDOOR OPERATION

  • Ring core or split CT
  • Hole diameters up to 225 mm
  • Various sizes available
  • Primary current up to 3000 A

Cable current transformers of type JK-G / JKS-G are used in outdoor applications for medium or high voltage systems. They are mounted over the high or medium voltage cable and transform currents up to 3000 A into standardised values for meters, measuring and protection tasks.

General description

Cable current transformers of type JK-G / JKS-G are used in outdoor applications for medium or high voltage systems. They are mounted over the high or medium voltage cable and transform currents up to 3000 A into standardised values for meters, measuring and protection tasks.

The cable provides the insulation against high voltage in this transformer type and also represents the primary winding of the current transformer. The current transformer itself is installed on a frame or cross-member over the cable.

The active parts are cast in a polyurethane resin protected by an aluminium housing. The split core current transformers are opened and closed with M8 screws located on the sides. With regards to installation, only vertical mounting with +/–60° deviation for reasons of outdoor reliability.

The secondary terminals are routed in a terminal box to M6 cast sockets. The connection to the secondary circuit can be realised with appropriately sized cable lugs.

Type JK-G
The type JK-G current transformer is a single unit. Up to 4 cores are possible, depending on the type. An IP 65 degree of protection is achieved here.

Type JKS-G
The type JKS-G current transformer has a split core. Maximum of two cores possible, dependent on the translation and class. An IP 53 degree of protection is achieved here.

Advantages
JK-G (JKS-G)
  • Suitable for subsequent installation over the cable in outdoor switchgear

  • Degree of protection possible up to IP 65 (IP 53)

  • Primary currents possible up to 3000 A

  • Suitable for up to 4 (2) current transformer cores, dependent on translation and class

  • 4 different transformer hole diameters: 85 mm, 115 mm, 145 mm, 225 mm
Technical data
Type JK-G / JKS-G
StandardIEC / IEEE
Highest voltage for equipmentkV0.72
Rated power-frequency withstand voltagekV3
FrequencyHz16.7 / 50 / 60
Primary rated currentA1 - 3000
Secondary rated currentA1 / 5
Rated short-time thermal current [Ith]kA / 1s100 x In
Rated dynamic current [Idyn]kA2.5 x Ith
Accuracy class0.1-3; 0.2S; 0.5S; P; PR; PX; PXR; TPX; TPY
Max. number of CT cores1
 
TypeJK-G
JKS-G
Diametermm80 / 110 / 14085 / 115 / 145