Qoltec 40A 3-Pole C-Curve Miniature Circuit Breaker MCB 4.5kA DIN Rail

In industrial control panels and commercial distribution boards, protecting three-phase circuits demands a breaker that combines precise tripping with robust construction. The Qoltec 52594 is a 3-pole miniature circuit breaker rated at 40 A with a C-curve characteristic, engineered to safeguard cables and equipment against overloads and short circuits. Its 4.5 kA breaking capacity and compliance with EN 60898-1 make it a dependable choice for electricians and panel builders working on 230/400 V AC systems.

Key specifications

• Type: Miniature Circuit Breaker (MCB)
• Number of poles: 3
• Rated current: 40 A
• Tripping characteristic: C-curve
• Rated voltage: 230/400 V AC
• Frequency: 50/60 Hz
• Short-circuit breaking capacity (Icn): 4.5 kA
• Mounting: DIN rail (35 mm)
• Standard: EN 60898-1
• Terminal capacity: 1–25 mm²
• Electrical endurance: 4,000 cycles
• Mechanical endurance: 10,000 cycles
• Protection degree: IP20 (terminals), IP40 (enclosure)
• Operating temperature: -25°C to +50°C
• Energy limiting class: 3
• Connection: screw terminals
• Indicator: trip indicator

Why choose it

This MCB delivers reliable protection for three-phase circuits with moderate inrush currents, such as motors, transformers, and lighting banks. The C-curve ensures it tolerates short-term surges without nuisance tripping while still responding quickly to genuine faults. Its compact DIN rail design simplifies installation in standard distribution boards, and the clear trip indicator helps identify a tripped breaker at a glance. Built to EN 60898-1, it meets rigorous safety and performance requirements for residential, commercial, and light industrial applications.

Ideal use cases

• Protecting three-phase motors and pumps in workshops and small factories
• Distribution boards in commercial buildings, retail spaces, and offices
• Control panels for HVAC systems, compressors, and conveyor lines
• Upgrading existing installations to meet current electrical standards

Good to know

The breaker supports both top and bottom feed, and its screw terminals accept conductors from 1 to 25 mm², accommodating a wide range of wiring sizes. With an operating temperature range of -25°C to +50°C, it performs reliably in harsh environments. The IP40 enclosure rating provides protection against solid objects larger than 1 mm, making it suitable for enclosed panels. Always verify local regulations and consult a qualified electrician for installation.