Technical specifications for Legrand Megatiker M4 thermal magnetic circuit breaker and MS4 isolating switch

Product Overview

Megatiker M4 is a high-end thermomagnetic molded case circuit breaker, and MS4 is a matching isolation switch, designed for high-power distribution scenarios, with high breaking capacity, easy installation, and multiple expansion features.

Product series and model range

1. Circuit breaker M4 (T743/T742/T744 series)

Rated current: 250/320/400/500/630A

Breaking level: F (36kA), N (50kA), H (70kA), L (100kA)

Polar numbers: 3P, 4P, 3P+N/2

2. Isolation switch MS4

Rated current: 400A, 630A

Extremes: 3P, 4P

Model: T743S400/630, T744S400/630

Size and weight

Overall dimensions

3P：140×260×105mm

4P：183×260×105mm

Weight (fixed type)

Configure 3P ≤ 400A 3P ≥ 500A 4P ≤ 400A 4P ≥ 500A

Circuit breaker 5.20kg 5.40kg 6.55kg 6.85kg

Isolation switch 5.00kg 5.25kg 6.40kg 6.68kg

Electrical and mechanical characteristics

General Parameters

Rated insulation voltage: 800V

Rated working voltage: 690VAC

Power frequency: 50/60Hz

Working temperature: -25~+70 ℃

Mechanical lifespan: 20000 cycles; Motor operation: 10000 times

Electrical lifespan (In): 4000 cycles; (0.5In): 8000 times

Breaking capacity (415VAC)

Level Icu (kA) Ics (% Icu)

F 36 100

N 50 100

H 70 100

L 100 70

Release parameters

Heat setting Ir: 0.8~1 × In

Magnetic tuning Ii: 5~10 × In

4P neutral wire protection: 100% phase polarity

Installation and wiring

Installation method: panel vertical/horizontal, reverse feeding

Wiring Type: Front Wiring, Rear Flat Wiring, Cage Terminal

Maximum cable: 300mm ² (hard)/240mm ² (soft)

Torque: 24Nm

Power consumption parameters (per pole)

Rated current phase pole power consumption (W) neutral pole power consumption (W)

250A 19.2 19.2

320A 16.4 16.5

400A 25.6 18.9

500A 23.6 28.7

630A 37.3 21.2

Capacity reduction characteristics

Temperature derating: rated current decreases gradually above 50 ℃

Altitude derating: voltage and current derating above 2000m

Structural derating: Plug in, pull-out, and leakage modules all require derating

Attachment system

Release device: shunt, undervoltage, delayed undervoltage, leakage module

Signal accessories: auxiliary contacts, fault signal contacts

Operating attachments: rotating handle, motor operating mechanism, padlock

Structural attachments: insertion/extraction base, terminal cover, phase insulation

Certification standards

Compliant with: IEC/EN 60947-2 (Circuit Breaker), 60947-3 (Switch)

Certification: CE, CCC, EAC, Classification Society (LR/RINA/BV)

Environmental Protection: REACH, RoHS, RAEE

Key issues

Question 1: What is the breaking level and corresponding breaking capacity of M4 circuit breaker, and how to select different levels?

Answer: M4 is divided into four levels: F (36kA), N (50kA), H (70kA), and L (100kA), all measured at 415VAC; Choose F/N for ordinary power distribution, and H/L for high industrial short-circuit risk scenarios.

Question 2: What are the adjustment ranges for thermal and magnetic trip of M4 circuit breaker, and what protection functions do they correspond to?

Answer: Thermal trip Ir=0.8~1 × In, used for overload long delay protection; Magnetic release Ii=5~10 × In, used for short-circuit instantaneous protection.

Question 3: How to reduce the capacity of M4 in high altitude and high temperature environments, and what is the most influential installation form?

Answer: When the altitude is greater than 2000m, the voltage and current are synchronously reduced in capacity; Temperature>50 ℃, current decreases; The combination of pull-out and leakage module has the most significant reduction in capacity, and the lowest reduction for the 630A model can be as low as 378A * *.