Air Circuit Breaker | ACB

CIRCUIT BREAKERS

MO air circuit breakers are designed to deliver robust and flexible protection across a wide current range, supporting up to 6300 A nominal current. They are available in three switching capacity classes and five types of electronic releases, providing tailored solutions for various applications. Offered in both 3-pole and 4-pole versions, these breakers ensure compatibility with diverse system configurations. The entire range from 630 A to 6300 A is efficiently covered with just three contact frame sizes, simplifying inventory and installation. Additionally, their use of rating plugs allows optimal adjustment of nominal current—starting from as low as 250 A, with a setting range of 0.4 to 1xIn—making MO breakers both versatile and cost-effective.

FRAME SIZE AND SHORT-CIRCUIT BREAKING CAPACITY

FRAME SIZE 1	FRAME SIZE 2	FRAME SIZE 3
250A	250A
315A	315A
400A	400A
500A	500A
630A	630A
700A	700A
800A	800A
1000A	1000A
1250A	1250A	1250A
1600A	1600A	1600A
2000A	2000A	2000A
	2500A	2500A
	3200A	3200A
	4000A	4000A
	5000A	5000A
		6300A

Rated Breaking Capacity

Icu at AC 500V (kA) / Icu at DC 300V (kA):

Frame Size 1: B = 55 kA, N = 66 kA
Frame Size 2: B = 66 kA, N = 80 kA
Frame Size 3: H = 100 kA

LOW VOLTAGE EQUIPMENT

The modular system for MO air circuit breakers, covering a current range from 630 A to 6300 A, is designed for flexibility and customization. The system includes a core breaker unit that can be configured with optional components to meet various protection and control needs. These components may include:

Electronic trip units for precise protection and monitoring
Auxiliary contacts for signaling and automation integration
Motor operators for remote operation
Shunt and undervoltage releases for advanced control logic
Communication modules for system integration (e.g., Modbus, Profibus)

System Components List

No.	Component Description
1	MO circuit breaker, between 630A and 6,300A
2	External expansion modules
3	Communication module for PROFIBUS
4	Position indicator contact: Module for guide frame
5	Main connection elements: a. Front connection b. Front connection, double hole c. Flange connection d. Horizontal connection, rear-side e. Vertical connection, rear-side
6	Guide frame
7	Auxiliary plug connector
8	Auxiliary contact
9	Motor operator
10	Operating cycle counter
11	Electronic release
12	Parametric device
13	Earth-fault protection module
14	4-line LCD display
15	Door sealing frame
16	Rating plug
17	EMERGENCY STOP mushroom push button
18	Closing magnet, voltage release