Introduction
In modern large-scale industrial power distribution systems, the main incoming circuit breaker undertakes the core protection task of the entire system, and its reliability, accuracy, and intelligence directly affect the continuity of power supply and equipment safety. The Megatiker M5 electronic circuit breaker launched by BTicino, as the flagship product of the Megatiker platform, is designed for large capacity current levels from 500A to 1600A. It adopts advanced electronic protection units, providing up to 100kA breaking capacity, accurate overload and short-circuit protection, as well as comprehensive power measurement and communication functions.
This article is based on the official technical documentation of BTicino, systematically reviewing the technical characteristics, electrical parameters, electronic protection unit functions, installation methods, accessory configurations, and trip characteristics of the Megatiker M5 electronic circuit breaker, providing professional references for engineers and system integrators.
Product positioning and scope
1. Product positioning
The Megatiker M5 series is positioned as the main incoming line protection for the high-end industrial power distribution market, with the following characteristics:
Large capacity: rated current covering 500A to 1600A
High segmentation capability: up to 100kA
Intelligent protection: electronic release unit, supporting multiple protection types such as Li, Lsi, Lsig
Integrated measurement: Real time monitoring of parameters such as current, voltage, power, and electrical energy
Flexible Installation: Supports both fixed and pull-out installation methods
Communication capability: Supports MODBUS RS485 communication for easy integration into monitoring systems
2. Product Scope
Electronic circuit breaker
According to different breaking capabilities, M5 circuit breakers are divided into four levels:
Breaking ability level Breaking ability Icu (415V AC)
F (36kA) 36 kA
N (50kA) 50 kA
H (70kA) 70 kA
L (100kA) 100 kA
Rated current levels: 500A, 630A, 800A, 1000A, 1250A, 1600A
Extremes: 3P and 4P versions
Size and weight
The M5 series adopts a large-sized modular design, suitable for high current applications:
Parameters 3P 4P
Width (W) 210 mm 280 mm
Height (H) 320 mm 320 mm
Depth (D) 140 mm 140 mm
Pole spacing 70 mm 70 mm
Weight Reference
Component weight (kg)
Fixed circuit breaker (3P) 18 kg (1250A)/18 kg (1600A)
Fixed circuit breaker (4P) 20 kg (1250A)/21.5 kg (1600A)
Pull out base (front wiring)+18 kg (3P)/+21.5 kg (4P)
Pull out base (rear wiring)+21.7 kg (3P)/+26.2 kg (4P)
Debro lift mechanism+9.9 kg (3P)/+11.2 kg (4P)
Supply content and installation method
1. Factory standard configuration
Each M5 circuit breaker comes with the following accessories at the factory:
Fixed screws (4 for 3P, 4 for 4P)
Wiring screws (6 for 3P and 8 for 4P)
Interphase insulation partitions (2 pieces for 3P, 3 pieces for 4P)
2. Installation method
The circuit breaker supports the following installation directions:
Vertical installation: standard installation method
Horizontal installation: suitable for cabinets with limited space
Reverse feeding: Supports upper or lower input lines, no LINE/LOAD marking required for reverse feeding
3. Installation form
Fixed type: directly installed on the panel
Pull out type: equipped with a "Debro lift" mechanism, supporting live plugging and unplugging, with three positions for connection, testing, and disconnection

Electrical and mechanical characteristics
1. Technical parameters of circuit breaker
Parameter values
Rated current In 500/630/800/1000/1250/1600 A
Pole number 3P/4P
Rated insulation voltage Ui 1000 V AC
Rated working voltage Ue 690 V AC
Rated impulse withstand voltage Uimp 8 kV
Rated frequency 50/60 Hz
Working temperature range -25 ° C to+70 ° C
Mechanical lifespan of 10000 cycles
Mechanical lifespan (with electric operation) 5000 times
Electrical lifespan (In) 4000 times
Electrical lifespan (0.5 × In) 8000 times
Use category B
Suitable for isolation is
2. Breaking ability (Icu)
The breaking capacity of M5 circuit breaker at different voltage levels is as follows:
Voltage 36kA (F) 50kA (N) 70kA (H) 100kA (L)
220/240V AC 70 kA 100 kA 105 kA 150 kA
380/415V AC 36 kA 50 kA 70 kA 100 kA
440/460V AC 30 kA 45 kA 65 kA 80 kA
480/500V AC 25 kA 35 kA 45 kA 55 kA
480/550V AC 20 kA 24 kA 28 kA 30 kA
600V AC 20 kA 24 kA 28 kA 30 kA
690V AC 14 kA 20 kA 22 kA 25 kA
3. Short circuit breaking capacity (Ics) during operation
F/N/H level: Ics=100% Icu
L level: Ics=70% Icu
4. Rated short-circuit making capacity (Icm @ 415V)
Breaking ability level Icm
F (36kA) 76.5 kA
N (50kA) 105 kA
H (70kA) 154 kA
L (100kA) 220 kA
Electronic protection unit
The core of the M5 series is its advanced electronic protection unit, which provides multiple protection types and precise adjustment functions.
1. Protection type
Li type protection
Long delay protection (L): Overload protection based on effective current value
Ir adjustable: 0.4 to 1 × In (1A step)
Tr options: 3s, 5s, 10s, 15s, 20s, 25s, 30s (7 levels)
Instantaneous protection (I): Short circuit instantaneous protection
Fixed threshold: 500-1250A is 15kA, 1600A is 20kA
Lsi type protection
Add short delay protection (S) on the basis of Li:
Short delay protection (S): Short circuit selective protection
Isd adjustable: 1.5 to 10 x Ir (11 levels)
Tsd adjustable: 0, 100, 200, 300, 400, 500 ms
Optional I ² t=K or t=K characteristics
Lsig type protection
Add ground fault protection (G) on the basis of Lsi:
Ground fault protection (G)
Ig adjustable: 0.2 to 1 × In (9 levels) and OFF
Tg adjustable: 0.1s, 0.2s, 0.3s, 0.4s, 0.5s, 1s
2. Measurement function
LCD display screen: Real time display of parameters such as current, voltage, power, and electrical energy
Internal battery: Parameter settings can still be made even when the circuit breaker is disconnected
USB port: used for local connection and configuration
Communication interface: Supports MODBUS RS485 protocol for remote monitoring
3. Self powered and auxiliary power supply
The electronic protection unit is normally powered by an internal current transformer (CT):
When the current is greater than 12% of the maximum power (single-phase load>20% In), the protection unit operates entirely on its own power supply
The measurement and display function is enabled when the current is greater than 20% of the maximum power (single-phase load>35% In)
To ensure continuous measurement and communication, it is recommended to use an external auxiliary power supply:
External auxiliary power module (M7ALIM)
MODBUS communication interface (M7COM)
Temporary power supply for USB port (5V DC)
4. Self diagnosis and protection
The protection unit has the following self diagnostic functions:
Over temperature protection: triggered when the internal temperature exceeds 95 ° C
Watchdog self-test: detects internal faults in the microcontroller to ensure reliable protection functions
Power loss and derating usage
1. Power loss per pole
In (A) Fixed front wiring (W) Fixed rear wiring (W) Pull out front wiring (W) Pull out rear wiring (W)
500 11.6 11.5 20.0 15.0
630 18.5 18.3 31.8 23.8
800 29.8 29.4 51.2 38.4
1000 47.6 47.0 82.0 60.0
1250 74.4 73.4 128.1 93.8
1600 65.3 58.9 112.6 97.3
2. Temperature reduction
The ambient temperature has a significant impact on the current carrying capacity of circuit breakers. The following table shows the maximum continuous operating current at different temperatures:
In (A) 50°C 60°C 70°C
500 500 500 500
630 630 630 630
800 800 800 720
1000 1000 1000 900
1250 1250 1250 938
1600 1600 1600 1360
3. Altitude Capacity Reduction
When the installation altitude exceeds 2000 meters, it is necessary to reduce the capacity according to the following coefficient:
Altitude (m) ≤ 2000 3000 4000 5000
Working voltage Ue (V) 690 590 520 460
Rated current In 1 × In 0.98 × In 0.93 × In 0.9 × In
4. Environmental adaptability
Climate conditions: comply with Appendix Q, Cat. F of IEC/EN 60947-1
Electromagnetic compatibility: Complies with Appendix F of IEC/EN 60947-2
Pollution level: Level 3

Accessories and Options
The M5 series offers a wide range of electrical and mechanical accessories to meet different application needs.
1. Release device
Split release (ST)
Voltage specifications: 24V, 48V, 110-130V, 220-250V, 380-440V (AC/DC)
Voltage range: 70% to 110% Un
Action time: ≤ 50 ms
Power consumption: 300 VA/W
Undervoltage Release (UVR)
Voltage specifications: 24V AC/DC, 48V DC, 110-125V AC, 220-240V AC, 380-415V AC
Operating voltage: 35% to 70% Un
Reset voltage: 85% to 110% Un
Action time: ≤ 50 ms
Delay module: can be equipped with 800ms delay module (M7000E/024, M7000MR/230, M7000MR/400)
2. Auxiliary contacts
Model: M7X01
Contact form: 1NO/NC conversion contact
Rated current: 3A @ 250V AC
Configuration: M5 supports up to 3 auxiliary contacts, 1 fault signal contact, and 1 release
3. Rotate the handle
Type and Model Description
Direct standard M7647 black handle
Variable depth standard T7649 IP55, black
Variable depth emergency T7649E IP55, red/yellow
Lock attachment M7R17 for variable depth handle, requires universal lock cylinder
4. Electric operating mechanism
Factory assembled type
Model: M7875P/024, M7875P/048, M7875P/230
Voltage: 24V, 48V, 230V AC/DC
Installation method: Pre operation
Customer assembly type
Model: 0 261 24 (24V), 0 261 25 (48V), 0 261 26 (110V), 0 261 23 (220V)
Scope of application: In ≤ 1250A
1600A dedicated: 0 261 19 (24V), 0 261 28 (48V), 0 261 29 (110V), 0 261 27 (220V)
5. Connect attachments
Cage terminal
Standard type: M7900/2 (2 × 185mm ² flexible/2 × 240mm ² rigid)
High Capacity Type: M7900/4 (4 × 185mm ² Flexible/4 × 240mm ² Rigid)
Expansion terminal
Short terminal: M7940/2 (500-1250A, maximum 2 busbars per pole)
Long terminal: M7940/3 (1600A, maximum of 3 busbars per pole)
Rear wiring terminal
Rotating: M7960 (3P), M7961 (4P)
Flat panel: M7950 (3P), M7951 (4P)
6. Pull out attachments
Pull out base
Front wiring: M7B25 (3P), M7B26 (4P)
Rear wiring: M7B27 (3P), M7B28 (4P)
Debro lift mechanism (moving parts)
3P:M7B29
4P:M7B30
Pull out attachment
Position signal contact: MT7910N
Pull out the handle: MT7412
Auxiliary contact (12 pins): M7B21
8-pin connector: M7500
7. Electronic version specific attachments
Auxiliary power module
Model: M7ALIM
Input voltage: 24V AC/DC (± 10%)
Installation method: 2 DIN modules
Purpose: To provide external power supply for electronic protection units, ensuring continuous operation of measurement functions
MODBUS communication interface
Model: M7COM
Input voltage: 24V AC/DC (± 10%)
Installation method: 1 DIN module
Function: Share circuit breaker data to MODBUS network
Features: Built in external power supply, no need for additional M7ALIM
Bluetooth communication key
Model: MPXX02
Function: Configure, monitor, and manage through the mobile app (EnerUp+Project)
Touch screen display unit
Model: PM1TS
Function: Display electrical parameters of up to 8 protective devices
Installation method: Panel or cabinet door installation (96 × 96 mm)
8. Mechanical accessories
Padlock: M7055, used to lock in the "off" position
Interphase insulation partition: M7695 (12 × 2 pieces)
Terminal protective cover: M7935 (3P), M7936 (4P)
IP20 terminal cover: M7C13 (3P), M7C14 (4P), M7X39 (external neutral wire)
9. Mechanical interlocking
Fixed interlocking board: M7198N
Insertion/extraction interlocking board: M7298N
10. Universal key lock
Support locking of rotating handle, electric operating mechanism, insertion mechanism, and extraction mechanism:
Lock cylinder type and model
Randomly encoded flat key M7K01
Fixed code EL43525 M7K02
Fixed code EL43363 M7K03
Randomly encoded star key M7K04
Release curve
The M5 electronic circuit breaker provides multiple trip curves for system coordination and design.
1. Long delay trip curve (Li/Lsi/Lsig)
Display the inverse time characteristic of overload protection (L)
Tr adjustable range: 3s to 30s (7-speed)
Curve varies with Ir and Tr settings
2. Short delay trip curve
Display the delay characteristics of short-circuit protection (S)
Tsd adjustable range: 0 to 500 ms
Optional I ² t=K or t=K characteristics
3. Instantaneous release curve
Fixed instantaneous trip value: 15kA (500-1250A)/20kA (1600A)
Ensure rapid response to extremely high short-circuit currents
4. Through the energy curve (I ² t)
Display the allowable conduction energy under different expected short-circuit currents
A lower I ² t value means better protection for downstream equipment
5. Peak current cut-off curve
Display the peak current that the circuit breaker can limit in the event of a short circuit fault
Intuitively reflect the current limiting performance of circuit breakers
Compliance and Certification
The Megatiker M5 series products comply with the following standards and regulations:
Product standard: IEC/EN 60947-2
International certifications: IECEE CB certification, LOVAG certification
Regional certification: CCC (China), EAC (Eurasian Union)
Ship certification: Lloyd's Register, RINA, Bureau Veritas Marine
Environmental directives: REACH, RoHS, WEEE (RAEE)
Environmental Product Declaration: PEP Ecopassport is available
The product label clearly indicates manufacturer information, model code, standard compliance, breaking capacity level (identified by color), barcode and other information for easy on-site identification and traceability.
Application scenarios and selection suggestions
1. Typical applications
Main incoming distribution: main incoming cabinets for factories, commercial buildings, and data centers
Large scale power distribution: Distribution circuits for large equipment
Generator protection: Generator set outlet protection
Transformer protection: Main protection on the low voltage side of the transformer
ATS system: main switch in the automatic switching system of main and backup power supply
2. Key selection points
Rated current: Choose specifications from 500A to 1600A based on the load current
Breaking capacity: Select F/N/H/L level based on system short-circuit current
Protection type: Choose Li, Lsi or Lsig, do you need ground fault protection
Measurement requirement: Is it necessary to integrate power measurement function
Communication requirements: Do you need MODBUS communication and remote monitoring
Installation method: fixed or pull-out
Attachment requirements: auxiliary contacts, shunt release, electric operation, rotating handle, interlock, etc
Environmental conditions: Temperature, altitude, humidity need to be considered for capacity reduction
