MCCB

MLM1 MCCB

The ML/MGM1 series are robust Molded Case Circuit Breakers (MCCBs) designed for reliable circuit protection in industrial applications. They offer a comprehensive range of frame sizes from 63A to 1250A, with rated currents from 10A to 800A. These breakers feature thermal-magnetic releases for both overload and instantaneous short-circuit protection, tailored for either distribution or motor circuits. With high breaking capacities up to 80kA (Icu) and options for various accessories like shunt trips and auxiliary contacts, they ensure safety and flexibility. The datasheet provides essential installation data, including conductor sizing, power loss, and derating factors for ambient temperatures up to 60°C.

Product Details

Product Descriprion

The MLM1 and MGM1 series are versatile Molded Case Circuit Breakers (MCCBs) engineered for superior performance in electrical distribution and motor protection. This comprehensive product line covers an extensive range, with frame sizes from 63A to 1250A and adjustable rated currents spanning 10A to 800A, available in 3-pole and 4-pole configurations.

A key feature is their protective release, which utilizes a thermal-magnetic mechanism. The inverse-time delay thermal unit handles overloads, while the magnetic unit provides instantaneous tripping for short-circuits. Specific models are calibrated for either distribution protection or motor protection, with detailed trip characteristics provided for each. The breakers boast a high rated insulation voltage of up to 800V and a formidable ultimate short-circuit breaking capacity (Icu) of up to 80kA at 415V AC, with specified values for 690V AC systems as well.

For installation and application engineering, the datasheet supplies critical data. This includes recommended conductor cross-sectional areas for each current rating, total power loss values for different models, and detailed derating factors for ambient temperature variations beyond the standard 40°C, extending to 60°C. A wide array of accessories, including shunt releases, under-voltage releases, and auxiliary contacts, enhance functionality. Compliant with IEC standards, these MCCBs are characterized by their high breaking capacity, rational design, and adaptability to various industrial environments, making them a dependable choice for complex power distribution systems.

Protection Characteristics

The thermal-magnetic release features an inverse time-delay characteristic.The magnetic-only release provides instantaneous tripping;its characteristics for distribution protection are listed in the table below.

Distribution Protection

Rated Current of Release,In(A)	Thermal Trip(Ambient Temperature: Land +40°C /Marine +45°C)		Magnetic Trip Setting (A)
	1.05 In(Cold State) No-trip time(h)	1.30 In(Hot State) Trip time (h)
10≤In≤63 63<In≤100	≤1	≤1	10In±20%
	≤2	≤2
100<In≤800	≤2	≤2	5In±20% 10In±20%

Motor Protection

Rated Current of- Release,In(A)

Thermal Trip(Ambient Temperature:Land +40°C /Marine+45°C)

Magnetic Trip

Setting(A)

1.0 In

(Cold State)

No-trip time (h)

1.20ln

(Hot State)

Trip time(h)

1.50In

(Hot State)

Trip time(h)

7.2 In

(Cold State)

Trip time (h)

10≤In≤250

250<ln≤800

≤2

≤4 min

≤8 min

4 s<Tp≤10 s

6 s<Tp≤20s

12ln±20%

Note: The 100A and 125A specifications for model MLM1-250 are equipped with a 5In magnetic-only release.

Release Methods and Accessory Codes

Model		MLM1-63			MLM1-125					MLM1-250
Number of poles		3		4	2	3			4	2	3			4
Frame size current		63			125					250
Rated current(A)		10,16,20,25,32 40,50,63			10,16,20,25,32 40,50,63,80,100					200,225,250
Rated insulation vohage(V)		500			800					800
Rated operational voltagefV)		380/400/415			380/400/415/690					380/400/415/690
Arcing distance(mm)		≤50			≤50					≤50
Breaking capacity code		S	H	H	H	S	H	R	H	H	S	H	R	H
Frame size rated current(A)		63	63	63	100	100	100	100	100	250	250	250	250	250
Ultimate short-circuit breaking capacity Icu (kA,RMS)	AC 380V/ 400V/415V	15	35	35	50	25	SO	65	50	50	25	50	65	50
	AC690V	一	一	一	8	3	8	10	8	8	5	8	10	8
Service short-circuit breaking capacity lcs (kA,RMS)	AC 380V/ 400V/415V	7.5	175	17.5	25	125	25	325	25	25	12.5	25	325	25
	AC690V	一	一	一	4	1.5	4	5	4	4	2.5	4	5	4
Fixed type		■			■					■
Rear connection		■			■					■
Plug in type		■			■					■
Shunt release		■			■					■
Under-voltage ralease		■			■					■
Auxiliary contact		■			■					■
Alarm contact		■			■					■

Model		MGM1-400					MGM1-630				MGM1-800		MGM1-1250
Number of poles		3			4		3		4		3	4	3
Frame size current		400					630				800		1250
Rated current(A)		225,250,315,350,400					400,500,630				630,700,800		700,800 1000,1250
Rated insulation vohage(V)		800					800				500		500
Rated operational voltage(V)		380/400/415/690					380/400/415/690				380/400/415		380/400/415
Arcing distance (mm)		<100					<100				<100		<100
Breaking capacity code		s	H	R	S	S	H	R	S	H	R	H	H
Frame size rated current(A)		400	400	400	400	630	630	630	630	800	800	800	1250
Ultimate short-circuit breaking capacity Icu (kA,RMS)	AC 380V/400V/415V	35	50	70	35	35	50	70	50	60	70	60	65
	AC 690V	10	12	15	10	12	13		12	–	–	–	–
Service short-circuit breaking capacity lcs (kA,RMS)	AC 380V/400V/415V	17.5	25	35	17.5	17.5	26	35	26	30	35	30	32.5
	AC 690V	5	6	7.5	5	6	6.5		6	–	–	–	–
Fixed type		■				■				■			■
Rear connection		■				■				■			■
Plug in type		■				■				■			■
Shunt release		■				■				■			■
Under-voltage release		■				■				■			■
Auxiliary contact		■				■				■			■
Alarm contact		■				■				■			■

Cross-Sectional Area of Connecting Conductors and Suitable Rated Currents

Rated Current (A)

16,20

40,50

100

125

160

180,200,

225

250

315,

350

400

Conductor Cross- Sectional Area

(mm²)

1.5

2.5

120

185

240

Rated Current(A)	Cable		Copper Busbar
	Cross-Sectional Area (mm²)	Quantity	Dimensions(mm×mm)	Quantity
500	150	2	30×5	2
630	185	2	40×5	2
700,800	200	2	40×5	2

Power Loss

Model	Energizing Current (A)	Total 3-Pole Power Loss (VA)
Model	Energizing Current (A)	Front/Rear Mounting	Plug-in Type
MLM1-63(L,M) Direct-Acting (10~25A)	25	28	32
MLM1-125 (L,M,H) Direct-Acting(10~25A)	25	40	45
MLM1-63(L,M) Indirect-Acting(32~63A)	63	20	24
MLM¹-125 (L,M,H) Indirect-Acting(32~125A)	125	35	40
MLM1-250(L,M,H)	250	62	70
MLM1-400(L,M,H)	400	115	125
MLM1-630(L,M,H)	630	187	200
MLM1-800(M,H)	800	262	-

Derating Factors for Ambient Temperature Variation

Model Factor Temperature	+40° C (Marine +50° C)	+45° C (Marine +50° C)	+50° C (Marine +50° C)	+55° C (Marine +50° C)	+60° C (Marine +50° C)
Model Factor Temperature	Derating Factor	Derating Factor	Derating Factor	Derating Factor	Derating Factor
MLM1-63 (L,M)	1 In	0.94 In	0.88 In	0.80 In	0.72 In
MLM1-125 (L,M,H)	1 In	0.95 In	0.89 In	0.84 In	0.76 In
MLM1-250 (L,M,H)	1 In	0.96 In	0.91 In	0.87 In	0.82 In
MLM1-400 (L,M,H)	1 In	0.94 In	0.87 In	0.81 In	0.73 In
MLM1-630 (L,M,H)	1 In	0.93 In	0.88 In	0.83 In	0.76 In
MLM1-800 (M,H)	1 In	0.88 In	0.83 In	0.79 In	0.76 In