3P 300A Electronic Molded Case Circuit Breaker

At the top of the distribution system pyramid, a current of 300A carries the lifeline of the entire area or core equipment. Traditional protection schemes are no longer able to balance the precision of protection, the selectivity of the system, and the intelligence of management. The SPX high-quality 3P 300A Electronic Molded Case Circuit Breaker is the innovator born for this purpose. It is not just a switch that trips in case of a fault, but also a local intelligent unit that integrates high-precision sensing, programmable logic, and data exchange. It marks the transition of molded case circuit breakers from the analog mechanical era to the digital intelligent era, becoming a key intelligent node for building reliable, transparent, and efficient distribution networks.

Feature

The customized 3P 300A Electronic Molded Case Circuit Breaker allows users to accurately set the protection current values and times for overload long delay (Ir), short circuit short delay (Isd), and instantaneous (Ii) over a wide range through an electronic release unit (ETU). This flexibility enables it to match the characteristics of different loads such as transformers, busbars, and large motors. 
The unique short delay protection function, by manually setting a short time delay (such as 0.1-0.4 seconds), ensures that in the event of a short circuit at the remote end, only the lower level circuit breaker closest to the fault point will operate, while the current level remains closed, thus achieving fully selective protection and minimizing large-scale power outages. 
Integrated adjustable ground leakage current protection (G function) effectively prevents electrical fires or personal electric shock accidents caused by insulation damage. The 3P 300A Electronic Molded Case Circuit Breaker provides a safety dimension that traditional circuit breakers do not have. 
A warning signal can be issued before the actual overload reaches the trip threshold. Its "thermal memory" function can simulate the thermal accumulation process of the motor, providing more reasonable protection under frequent starting conditions. 
It can record the types of faults (overload, short circuit, grounding, etc.) that have been tripped several times recently, the fault phase, and the current value during the action, providing key data for rapid fault diagnosis. 
Standard or optional communication modules (such as Modbus, Profibus) are available to upload real-time full power parameters such as three-phase current, voltage, power, power factor, and electrical energy, enabling digital monitoring of the distribution system.

Application

As the main protection switch for precision air conditioning, UPS input/output, and high-voltage DC power supply in the computer room, and monitoring their energy consumption.
As a low-voltage side outgoing switch in the main distribution cabinet of the workshop, or as a main line for protecting dense bus ducts.
The 3P 300A Electronic Molded Case Circuit Breaker provides intelligent protection and control for large water pumps, fans, compressors, and central refrigeration units below 250kW.
As a 3P 300A Electronic Molded Case Circuit Breaker for low-voltage main incoming lines or important partition distribution in large shopping malls, hospitals, and airports, it achieves energy management and demand control.

The SPX SM30-400 Series Of Moulded Case Circuit Breaker MCCB Parameter

Frame(A)		SM30-400(NF-CW)						Operating characteristics
Rated current in(A)		250、300、315、350、400
Rated voltage(V)		AC 400V
Rated insulation voltage(V)		AC 690V
Number of poles		3			4
Limited breaking capacity		C	S	H	C	S	H
Short circuit interrupting circuit(kA) AC400V		25	35	50	25	35	50
Operate short circuit(kA) AC400V		15	20	25	15	20	25
Profile picture
	a	258			258
	b	140			185
	c	153			153
Mounting picture
	d	195			195
	e	45			45
	f	8			8
Machine life		4000
Electrical life		1500
Electrical-operation device(MD)		●
Extemal rotary handle		●
Automatic tripping device		Thermal-magnetic