China SJKM3 MCCB Moulded Case Circuit Breaker Supplier - Factory-Direct Overload Protection & Circuit Safety

The SJKM3 MCCB Moulded Case Circuit Breaker is designed to provide advanced circuit protection for both 50Hz and 60Hz systems, accommodating voltages up to 690V and currents up to 1250A. This circuit breaker combines overload, short-circuit, and undervoltage protection features, ensuring reliable performance for industrial and commercial applications. With an impressive 800V insulation rating, a compact design, and a high-breaking capacity that minimizes arc flash, the SJKM3 MCCB is ideal for power distribution and motor protection during infrequent starts, Manufactured to comply with IEC60947-2 and GB14048.2 standards, this product can be installed both vertically and horizontally, making it versatile for various setups. Importantly, the innovative trip unit of the SJKM3 MCCB ensures precise fault detection while maintaining stable operation under varying load conditions. As a trusted product from China, sourcing this MCCB from reputable suppliers or directly from the factory guarantees superior fault protection along with space-saving advantages for your electrical systems

Product Details

Type Designation

SJKM3-MCCB-Moulded-Case-Circuit-Breaker-3

1	Manufacturer Identification Code
2	Molded Case Circuit Breaker Code
3	Design Serial Number
4	Frame Rating Current
5	Breaking Capacity Characteristic Code
6	Operation Mode Code: No code for manual operation, "P" for power operation, "Z" for rotary handle operation
7	Number of Poles
8	Trip Unit Type & Accessory Code
9	Application Code: No code for distribution application, "2" for motor protection application
10	Neutral Pole Type for 4-Pole Breakers

Product Display

SJKM3-MCCB-Moulded-Case-Circuit-Breaker-(1)

SJKM3-MCCB-Moulded-Case-Circuit-Breaker-(2)

Technical Parameters

Frame Rated Current Inm (A)		63		100		250		400		630		800
Model		SJKM3-63L	SJKM3-63M	SJKM3-100L	SJKM3-100M	SJKM3-250L	SJKM3-250M	SJKM3-400L	SJKM3-400M	SJKM3-630L	SJKM3-630M	SJKM3-800L	SJKM3-800M
Number of Poles		3/4		3/4		3/4		3/4		3/4		3/4
Rated Current In (A)		10/16/20/25/ 32/40/50/63		10/16/20/25/32/40/ 50/63/80/100		100/125/140/160/ 180/200/225/250		225/250/315/350/400		400/500/630		400/500/630/ 700/800
Rated Insulation Voltage Ui (V)		AC800		AC800		AC800		AC800		AC800		AC800
Rated Impulse Withstand Voltage Uimp (V)		8000		8000		8000		8000		8000		8000
Rated Operational Voltage Ue(V) 50Hz/60Hz		AC400		AC400	AC400 AC690	AC400	AC400 AC690	AC400	AC400 AC690	AC400	AC400 AC690	AC400	AC400 AC690
Arc Distance (mm)		≯50(0)		≯50(0)		≯50(0)		≯100(0)		≯100(0)		≯100(0)
Rated Ultimate Short-circuit Breaking Capacity Icu (kA)	AC400V	35	50	50	70	50	70	50	70	50	70	65	75
	AC690V				20		20		20		20		30
Rated Service Short-circuit Breaking Capacity Ics (kA)	AC400V	22	35	35	50	35	50	50	50	50	50	65	65
	AC690V				10		10		15		15		20
Utilization Category		A		A		A		A		A		A
Electrical Endurance (operations)	AC400V	8000		8000		8000		7500		7500		7500
	AC690V				1500		1000		1000		1000		500
Mechanical Endurance (operations)	Maintenance-free	20000		20000		20000		10000		10000		10000
	With maintenance	40000		40000		40000		20000		20000		20000
Overall Dimensions (mm)	W (3P/4P)	75/100		92/122		107/142		150/198		182/240		210/280
	L	130		150		165		257		270		280
	H	60		92		90		106.5		110		115.5

Note：

1. According to GB14048.1, the term "Endurance" represents the probability of operation cycles completed by the electrical device before repair or replacement of components.

2. Select zero-arc chutes with heights of: 4mm (for SJKM3-63L/M), 6.2mm (for SJKM3-100L/M), 7.5mm (for SJKM3-250L/M), 9.3mm (for SJKM3-400L/M and SJKM3-630L/M), 9.5mm (for SJKM3-800L/M) to achieve zero-arc (arc-free) performance.

Overall Dimensions and Installation Dimensions

Model	Number of Poles	Overall Dimensions								Installation Dimensions
		A		B		C		D
		L	M	L	M	L	M	L	M	a	b	Ad
SJKM3-63L/M	3	75		130		81	90	60	70	25	111	3.5
	4	100								50
SJKM3-100L/M	3	92		150		90	110	72	92	30	129	4.5
	4	122								60
SJKM3-250L/M	3	107		165		110	127	90	107	35	126	4.5
	4	142								70
SJKM3-400L/M	3	149		257		155		112		44	194	7
	4	198								94
SJKM3-630L/M	3	182		270		160		117		58	200	7
	4	240								116
SJKM3-800L/M	3	210		280		155		113		70	243	7
	4	280								140

Frequently Asked Questions

Q1: What does the type designation code of the SJKM3 MCCB represent?

The type designation of the SJKM3 Moulded Case Circuit Breaker encodes key product information including the manufacturer identification, MCCB code, design serial number, frame rating current, breaking capacity characteristic, operation mode, number of poles, trip unit type, application code, and neutral pole type for 4-pole breakers.

Q2: What frame rated current options are available for the SJKM3 MCCB series?

The SJKM3 series is available in six frame rated current sizes: 63A, 100A, 250A, 400A, 630A, and 800A, with both L (standard breaking) and M (high breaking) variants for each frame size.

Q3: What is the rated insulation voltage and impulse withstand voltage for all SJKM3 models?

All SJKM3 MCCB models share a rated insulation voltage (Ui) of AC800V and a rated impulse withstand voltage (Uimp) of 8000V, ensuring robust insulation performance across the entire product range.

Q4: What is the difference between the "L" and "M" models in the SJKM3 series?

The "L" designation indicates standard breaking capacity, while "M" denotes higher breaking capacity. For example, the SJKM3-63L has an Icu of 35kA at AC400V, whereas the SJKM3-63M offers 50kA at AC400V, providing greater protection in demanding electrical environments.

Q5: How do I achieve zero-arc (arc-free) performance with the SJKM3 breaker?

Zero-arc performance is achieved by selecting appropriately sized zero-arc chutes: 4mm for SJKM3-63L/M, 6.2mm for SJKM3-100L/M, 7.5mm for SJKM3-250L/M, 9.3mm for SJKM3-400L/M and SJKM3-630L/M, and 9.5mm for SJKM3-800L/M.

Q6: What operation modes are supported by the SJKM3 Moulded Case Circuit Breaker?

The SJKM3 MCCB supports three operation modes: manual operation (no code), power operation (designated by "P"), and rotary handle operation (designated by "Z"), offering flexible installation and operation options for different application scenarios.