ABB S204-D40 Miniature Circuit Breaker | 4P 40A D-Type MCB Specs

ABB S204-D40 miniature circuit breaker specifications. 4-pole, 40A, D-type trip curve, 6kA breaking capacity, 230/400V AC. For industrial and commercial distribution systems.

ABB S204-D40 Miniature Circuit Breaker

The ABB S204-D40 is a 4-pole miniature circuit breaker (MCB)​ from the S200 series, featuring D-type trip characteristic​ and 40A rated current. This thermal-magnetic circuit breaker provides reliable overload and short-circuit protection for 3-phase + neutral distribution systems in commercial and industrial applications. With a breaking capacity of 6kA at 400V AC, it ensures safe operation in standard electrical installations.

Key Features

• 4-Pole Configuration:​ Protects 3-phase + neutral circuits (L1, L2, L3, N)

• D-Type Trip Characteristic:​ Suitable for circuits with high inrush currents (motors, transformers, etc.)

• 40A Rated Current:​ Standard current rating for medium-power applications

• 6kA Breaking Capacity:​ Adequate for most commercial and light industrial installations

• DIN Rail Mounting:​ Standard 35mm DIN rail installation for easy integration

• Thermal-Magnetic Protection:​ Combined thermal (overload) and magnetic (short-circuit) protection

Technical Specifications

Model Number Decoding (S204-D40)

• S2:​ Series identifier (S200 series)

• 04:​ Number of poles (4 poles = 3 phases + neutral)

• D:​ Trip characteristic (D-type = high magnetic trip)

• 40:​ Rated current (40 amperes)

Key Differences from Other ModelsCompared to similar ABB MCBs:

• S204-D40:​ 4P, 40A, D-type, 6kA (this model)

• S204-C40:​ 4P, 40A, C-type (standard trip), 6kA

• S204-D32:​ 4P, 32A, D-type, 6kA

• S204-D50:​ 4P, 50A, D-type, 6kA

• S204M-D40:​ 4P, 40A, D-type, 10kA (higher breaking capacity)

The D-type trip characteristic​ is the key differentiator, making this model suitable for circuits with high inrush currents.

Typical Applications

• Motor Circuits:​ Protection of 3-phase motors with high starting currents

• Transformer Protection:​ Distribution transformers and control transformers

• Industrial Equipment:​ CNC machines, compressors, pumps with high inrush

• Commercial Lighting:​ High-intensity discharge (HID) lighting systems

• Power Distribution:​ 3-phase + neutral distribution boards in commercial buildings

• HVAC Systems:​ Air conditioning units and ventilation equipment

Important Selection & Installation Notes

1. Trip Characteristic Selection:​ D-type MCBs are specifically designed for circuits with high inrush currents (typically 10-20 times rated current). Do not use for general lighting or socket circuits where C-type is more appropriate.

2. Cable Sizing:​ Ensure cable cross-section is rated for at least 40A continuous current. Use 6-10 mm² copper cable for standard installations.

3. Short-Circuit Coordination:​ Verify that the upstream protective device (fuse or circuit breaker) provides proper coordination. The 6kA breaking capacity may require additional protection in high fault current installations.

4. Ambient Temperature:​ Derating may be required if installed in ambient temperatures above 40°C. Consult manufacturer's derating curves.

5. Installation:​ Mount on standard 35mm DIN rail. Ensure proper torque on terminal screws (typically 2.5-3.0 N·m for 35mm² cables).

6. Neutral Pole:​ The 4th pole is for neutral protection. In TN-C systems, neutral should not be interrupted (check local regulations).

7. Maintenance:​ Regular inspection recommended. Test trip functionality periodically using appropriate test equipment.

Note: Specifications are based on ABB S200 series technical documentation and industry standards. For complete installation guidelines, test procedures, and detailed technical data, consult the official ABB S200 Series Technical Manual​ or contact ABB technical support.