Rated voltage: 24 kV
Rated frequency: 50 Hz (or 60 Hz)
Rated current:
Main bus: usually 1250A, 1600A, 2000A, 2500A, 3150A, 4000A, etc.
Feeder/incoming line/bus tie circuit: 630A, 800A, 1250A, 1600A, 2000A, 2500A, 3150A, etc.
Rated short-time withstand current (thermal stability current - Icw): usually 25kA, 31.5kA, 40kA (4s), etc.
Rated peak withstand current (dynamic stability current - Ipk): usually 63kA, 80kA, 100kA, etc. (generally 2.5 times of Icw).
Rated short-circuit breaking current (Isc): usually 25kA, 31.5kA, 40kA, etc. (depending on the circuit breaker, such as VS1, VD4, VEP and other vacuum circuit breakers).
Rated short-circuit closing current: equal to the rated peak withstand current (Ipk).
Rated insulation level:
1min power frequency withstand voltage (phase-to-phase, phase-to-ground): 65 kV
Lightning impulse withstand voltage (peak, phase-to-phase, phase-to-ground): 125 kV
Isolation break withstand voltage: usually higher than the relative level (such as power frequency 79kV, impulse 145kV).
Protection level:
Casing: IP4X (prevents solid foreign objects with a diameter greater than 1mm).
When the circuit breaker door is open: IP2X (prevents solid foreign objects with a diameter greater than 12.5mm).
Internal compartments: metal partition isolation.
Main circuit resistance: ≤ specified value (μΩ), depending on circuit configuration and current level.
Mechanical life:
Circuit breaker trolley: usually 10,000 times (maintenance-free type can reach 30,000-50,000 times).
Earthing switch: usually 2,000 times.
Dimensions (W x D x H): Typical dimensions are approximately 800mm x 1500mm (1650mm) x 2200mm (2300mm) (single cabinet), which is more compact than KYN61-40.5, but varies greatly between manufacturers and configurations (such as cable entry).
High safety: Armored structure, independent compartment, automatic valve, forced five-protection interlock, directional pressure relief and other designs provide the highest level of personal and equipment safety protection.
High reliability: Mature and stable design, using mainstream vacuum circuit breakers (such as VS1, ZN63, VD4, etc.), key components are of reliable quality, ensuring long-term stable operation.
Convenient maintenance: The removable design is its biggest advantage. Circuit breaker maintenance or replacement does not require disassembly of the main circuit, and can be directly pulled out/pushed into the trolley, greatly shortening the power outage time and improving power supply continuity. Out-of-cabinet maintenance is safer and more convenient.
Compact design: Compared with 40.5kV cabinets (such as KYN61), KYN28A-24 is smaller in size, saves floor space, and is particularly suitable for distribution rooms with limited space.
Flexibility and scalability: The modular design is easy to combine into various main wiring schemes (incoming, outgoing, busbar, PT, metering, station transformer, etc.). The busbar can be easily expanded or cabinets can be added.
Good applicability: It can meet the requirements of conventional indoor environments (temperature, humidity, altitude ≤1000m, and capacity reduction is required for higher altitudes).
Intelligent interface: The relay instrument room is easy to integrate various intelligent protection and control devices, communication management units, and support the needs of digital substations.
24kV voltage level power distribution system for industrial and mining enterprises (low-voltage side outgoing line of main transformer, high-voltage power distribution in factory area).
Main distribution station or regional distribution station for commercial complexes, high-rise buildings, hospitals, and data centers.
Booster station collector line switchgear or station distribution for wind farms and photovoltaic power stations.
Upper power supply incoming line cabinet for switchgear and ring network cabinet.
Control and protection of large motors.
