ABB 1TNA900241R0185 Current Transformer KORC 4SL 185/4

ABB 1TNA900241R0185 Current Transformer KORC 4SL 185/4

Let's break down the part number ABB 1TNA900241R0185 KORC 4SL 185/4.

This is a technical designation for a specific type of current transformer. Here is a detailed explanation of what each part of that code means.

Overall Description

This is a KORC series ring-type (window-type) current transformer from ABB, designed for electrical measurement and protection systems. It has a large window diameter and is rated for a primary current of 185 A.

Part Number Breakdown: 1TNA900241R0185

This is ABB's internal article number. While the structure can be complex, we can infer the following:

• 1TNA900241: This is the base product code for the KORC series transformer with specific characteristics (like accuracy class, insulation, etc.).

• R0185: This almost certainly indicates the Rated Primary Current.

◦ R likely stands for "Rated".

◦ 0185 indicates 185 Amperes.

Technical Code Breakdown: KORC 4SL 185/4

This is the more descriptive technical code.

1. KORC: This is the Product Series.

◦ KO indicates it's a ring-type (window-type) current transformer. It doesn't have a solid primary winding; instead, the main conductor (the cable or busbar) is passed through the window.

◦ RC likely specifies the design variant, mechanical features, and terminal type.

2. 4SL: This defines the Accuracy Class and Burden.

◦ 4: The Accuracy Class. For this type of transformer, this means it is accurate to within ±4% of the actual current at its rated burden. This is a standard class for general measurement and load monitoring.

◦ SL: The Rated Burden (Load). In this case, SL corresponds to a specific VA (Volt-Ampere) rating, which is typically 15 VA for KORC transformers. The burden is the maximum load that can be connected to the secondary without exceeding the accuracy class.

3. 185/4: This specifies the Rated Current Ratio.

◦ 185: The Rated Primary Current (Ipn). This is the nominal current for which the transformer is designed. The main conductor carrying up to 185A is passed through the window.

◦ 4: The Rated Secondary Current (Isn). This is a standard value of 4 Amperes. This means when 185A flows in the primary, the transformer will output 4A on its secondary terminals (into the specified burden).

Key Specifications (Summary)

Feature

Specification

Meaning

Type

Ring/Window Type (KORC)

The main conductor passes through the hole.

Primary Current (Ipn)

185 A

The nominal current it's designed for.

Secondary Current (Isn)

4 A

The standard output current.

Ratio

185/4

185A in : 4A out.

Accuracy Class

4

Accuracy is within ±4%.

Rated Burden

15 VA (typical for SL)

The maximum load on its secondary.

Function

Measurement & Protection

Suitable for panel meters, energy meters, and protection relays.

Typical Application

This current transformer would be used in a low-voltage or medium-voltage switchgear, panelboard, or distribution cabinet. A main power cable or busbar carrying up to 185A is fed through its central window. The secondary terminals are then connected to:

• An ammeter

• A kWh (energy) meter

• A protection or monitoring relay

The meter or relay sees a reduced, proportional current (4A at full load), which is safe and standardized for instrumentation.