4P 350A Molded Case Circuit Breaker

In large buildings or industrial facilities with a power capacity of several hundred kilowatts, the complexity and safety requirements of the distribution system are growing exponentially. The SPX customized 4P 350A Molded Case Circuit Breaker is designed specifically for the "source" or "aorta" of such complex systems. It goes beyond a single protection function and undertakes three core missions: cutting off fault currents, managing harmonic currents generated by non-linear loads (such as IT equipment and frequency converters) that return to the neutral line, and providing absolute safety and complete electrical isolation during maintenance. It is the 'stabilizing force' that ensures the safe and stable operation of the system even under huge, unbalanced, and harmonic rich loads.

Advantage

In high-capacity nonlinear load systems, the third harmonic current will superimpose on the neutral line, causing its current to far exceed the phase line current. The N pole of the 4P 350A Molded Case Circuit Breaker has overload and short circuit protection capabilities of the same level as the phase pole (350A), which can reliably operate in this abnormal situation and prevent the neutral wire from overheating and catching fire due to long-term overload. This is a fundamental safety hazard that cannot be solved by a three pole circuit breaker.
When any grounding or short circuit fault occurs, the four poles achieve millisecond level synchronous disconnection, and the faulty circuit (including potentially live N wires) is completely isolated from the power supply side, providing the highest level of safety protection for personnel and equipment, fully complying with the strict requirements for total isolation electrical appliances in IEC and GB standards.
Equipped with an electronic release unit, it can finely set protection parameters for each of the four poles. The short delay protection function of high quality 4P 350A Molded Case Circuit Breaker is the key to achieving fully selective tripping of upper and lower levels, ensuring that only the minimum range is isolated in the event of a fault; At the same time, it can monitor and record the current of each phase and neutral line, providing data support for power quality analysis and fault tracing.
Adopting a large capacity framework design, it has excellent heat dissipation performance and dynamic thermal stability, and can withstand a continuous current of 350A and high-intensity short-circuit electric shock.
It can integrate four pole auxiliary contacts, alarm signals, shunt/undervoltage release devices, and electric operating mechanisms, easily achieving remote monitoring, automatic switching, and linkage with building management systems.

Application

The customized 4P 350A Molded Case Circuit Breaker serves as the main incoming circuit breaker for the data center floors under the TN-S power supply system, protecting and isolating the power distribution system containing a large number of single-phase server cabinets, effectively managing the 3rd harmonic.
The low-voltage side main switch of transformers in large shopping centers, super high-rise office buildings, and star rated hotels meets the requirements of safety regulations for isolating all live conductors.
Sports venues, theaters, tertiary hospitals and other important places with multiple single-phase loads must use 4P 350A Molded Case Circuit Breaker for their main distribution cabinets to ensure safety and compatibility.
The 4P 350A Molded Case Circuit Breaker provides power protection and neutral line harmonic current protection for large welding workshops and production lines with centralized variable frequency drive equipment.

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