S203M-K50NA

Name: S203M-K50NA
Brand: ABB
SKU: S203M-K50NA

The ABB S203M-K50NA is a 50A, 3P miniature circuit breaker designed for reliable overload and short-circuit protection. It features delayed thermal and electromechanical tripping mechanisms, making it suitable for residential, commercial, and industrial applications.

Product ModelS203M-K50NA

Material Number2CDS273103R0577

Product ID78747

Stock on Request

Last updated: 8/29/2026

Quantity

Key Features

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1. Reliable Protection MechanismsThe S203M-K50NA boasts two advanced tripping mechanisms: delayed thermal for overload protection and electromechanical for short-circuit protection, ensuring your electrical system is safeguarded against various hazards.
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2. Comprehensive ComplianceThis miniature circuit breaker complies with IEC/EN 60898-1 and IEC/EN 60947-2 standards, making it suitable for a wide range of applications, including residential, commercial, and industrial settings.
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3. High Breaking CapacityWith a breaking capacity of up to 10 kA at 230/400 V AC, the S203M-K50NA can handle high short-circuit currents effectively, providing robust protection for your electrical system.
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4. Space-Efficient DesignThe compact design of the S203M-K50NA allows for efficient use of space in your electrical panel, making it ideal for installations where space is limited.

Technical Specifications

Detailed engineering parameters based on manufacturer documentation

Specifications may be subject to change without notice

Parameter

Value

Parameter

Value

Standards

CSA 22.2 No. 235 IEC/EN 60947-2 UL 1077

Tripping Characteristic

Rated Operational Voltage

acc. to IEC 60898-1 400 V AC acc. to IEC 60898-1 400 V acc. to IEC 60947-2 440 V AC

Operational Voltage

Maximum (Incl. Tolerance) 440 V AC Minimum 12 V AC Minimum 12 V DC

Rated Insulation Voltage (Ui)

acc. to IEC/EN 60664-1 440 V

Rated Impulse Withstand Voltage (Uimp)

5. Easy InstallationThe S203M-K50NA features a simple and intuitive installation process, ensuring that you can quickly and easily integrate it into your electrical system without complex setup requirements.

4 kV at 2000 m 5 kV at Sea Level 6.2 kV

Dielectric Test Voltage

50/60 Hz-1 min: 2 kV

Input Voltage Type

Rated Current (In)

50 A

Rated Short-Circuit Capacity

(AC) 10 kA (DC) 10 kA (230 V AC) 10 kA (400 V AC) 10 kA (400 V) 10 kA

Rated Ultimate Short-Circuit Breaking Capacity (Icu)

(230 V AC) 25 kA (400 V AC) 15 kA (440 V AC) 15 kA (230 V) 25 kA (400 V) 15 kA

Rated Conditional Short-Circuit Current (Inc)

(230 V) 25 kA (400 V) 15 kA

Rated Service Short-Circuit Breaking Capacity (Ics)

(133 V AC) 15 kA (230 V AC) 7.5 kA

Rated Frequency (f)

50 / 60 Hz

Power Loss

12.4 W at Rated Operating Conditions per Pole 3.1 W

Power Supply Connection

Arbitrary

Contact Position Indication

Red ON / Green OFF

Energy Limiting Class

Mechanical Endurance

20000 cycle

Number of Protected Poles

Number of Poles

3+N

Overvoltage Category

III

Position of Neutral Terminals

Right

Tightening Torque

2.8 NÂ·m

Screw Terminal Type

Failsafe Bi-directional Cylinder-lift Terminal

Actuator Marking

I / O

Actuator Material

Insulation Group II, Black, Sealable

Housing Material

Insulation Group II, RAL 7035

Mounting on DIN Rail

TH35-15 (35 x 15 mm Mounting Rail) acc. to IEC 60715 TH35-7.5 (35 x 7.5 mm Mounting Rail) acc. to IEC 60715

Mounting Position

any

Recommended Screw Driver

Pozidriv 2

Accessories Available

Yes

Connecting Capacity

Busbar 10 / 10 mmÂ² Flexible with Ferrule 0.75 ... 25 mmÂ² Flexible 0.75 ... 25 mmÂ² Flexible 0.75 ... 25 mmÂ² Rigid 0.75 ... 35 mmÂ² Rigid 0.75 ... 35 mmÂ² Stranded 0.75 ... 35 mmÂ²

Installation Size

acc. to DIN 43880 1

Terminal Type

Screw Terminals

Ambient Air Temperature

Operation -25 ... +55 Â°C Storage -40 ... +70 Â°C

Reference Ambient Air Temperature

30 Â°C

Degree of Protection

IP20 IP40 Enclosure with Cover IP40

Pollution Degree

Environmental Conditions

28 cycles with 55 Â°C / 90-96 % and 25 Â°C / 95-100 %

Resistance to Vibrations

20 Cycles with Load 0.8 In: 5g 5 ... 150 ... 5 Hz

Resistance to Shock acc. to IEC 60068-2-27

25g 2 shocks 13 ms

Maximum Operating Voltage UL/CSA

125 V DC 480Y / 277 V AC

Interrupting Rating acc. to UL1077

(125 V DC) 10 kA (277 V AC) 6 kA (480Y / 277 V AC) 6 kA

Connecting Capacity UL/CSA

Busbar 14-8 AWG Conductor 14-4 AWG

Tightening Torque UL/CSA

18 inÂ·lb

Width in Number of Modular Spacings

4.0

Product Net Width

70 mm

Product Net Height

88 mm

Product Net Depth / Length

69 mm

Product Net Weight

0.5 kg

Pole Net Weight

0.125 kg

Built-In Depth (t2)

69 mm

Dimension Diagram

2CDC022007F0010

ETIM 8

EC000042 - Miniature circuit breaker (MCB)

ETIM 9

EC000042 - Miniature circuit breaker (MCB)

WEEE Category

5. Small Equipment (No External Dimension More Than 50 cm)

WEEE B2C / B2B

Business To Business

CN8

8536 20 10

UNSPSC

39121603

eClass

V11.0 : 27141901

IDEA Granular Category Code (IGCC)

4897 >> Miniature circuit breakers

Object Classification Code

Manufacturer ID

2CDS273103R0577