ABB KORC 4S 235R4 1SCA022193R7410 1SCA022142R2080 current transformer

 ABB KORC 4S 235R/4 is a high-precision window-type (ring-core) current transformer designed for medium-voltage (MV) power systems up to 12kV. Part of ABB's industry-renowned KORC series, this CT provides accurate current measurement and reliable protection signals for switchgear applications, including ABB UniGear ZS1 and other metal-enclosed switchgear panels .

This model is available under two ABB ordering codes:

1SCA022193R7410

1SCA022142R2080

Both codes refer to the same core specification and are fully interchangeable.

Key Features & Benefits

Feature Benefit

Ring-core (window-type) design Easy installation on cables or busbars without cutting primary conductors; ideal for both new panel builds and retrofit projects

Protection-class accuracy Designed specifically for protection applications (Class S), ensuring accurate operation during fault conditions

235A primary rating Ideal for medium-power feeders, transformer protection, and motor control center applications

Standardized 4A secondary output Compatible with most protection relays and metering devices

Compact footprint Fits seamlessly into ABB and third-party switchgear compartments

IEC compliance Manufactured to international instrument transformer standards, ensuring global acceptance and reliability

ABB original quality Backed by ABB's global manufacturing and technical support network

Technical Specifications

Parameter Value

Brand ABB

Series KORC 4S

Type Window-type / Ring-core Current Transformer

Rated Primary Current (Ipr) 235 A

Rated Secondary Current (Isr) 4 A

Turns Ratio 235:4

Core Function Protection (Class S)

Rated Insulation Voltage 12 kV (suitable for 12kV systems) 

Frequency 50/60 Hz

Window Diameter Approx. 40 mm (size 4S) 

Standards IEC 61869-1, IEC 61869-2

Accuracy Class Information

The "S" designation in KORC 4S indicates the core is designed for Protection purposes . Protection cores are characterized by:

Parameter Typical Value

Accuracy Class 5P (standard protection class)

Composite Error ≤5% at rated accuracy limit current

Accuracy Limit Factor (ALF) 10 or 20 (consult datasheet for exact specification)

Note: For precise accuracy limit factor and burden rating, refer to the official ABB datasheet or product nameplate.

Model Number Decoding

Code Meaning

KORC ABB current transformer series designation (KOre Ring Current Transformer) 

4S Series design framework; "4" indicates voltage class (7.2kV/12kV), "S" indicates Protection core

235 Rated primary current: 235 Amperes

R Standard configuration (ring-type / window-type)

/4 Rated secondary current: 4 Amperes

1SCA022193R7410 ABB ordering code (primary ordering number)

1SCA022142R2080 ABB ordering code (alternative / legacy number)

Applications

The ABB KORC 4S 235R/4 is specifically designed for protection applications in:

Medium-voltage switchgear – ABB UniGear ZS1, UniGear ZS3.2, and similar MV panels 

Feeder protection – Detecting overcurrent and short-circuit faults on outgoing power lines

Transformer protection – Primary side current sensing for transformer differential and overcurrent protection

Motor control centers (MCCs) – Medium-voltage motor feeder protection

Power distribution substations – 12kV industrial and utility applications

Protection relay input – Feeds overcurrent, short-circuit, and earth fault protection devices