Introduce
FZ(R)N21-40.5D indoor high-voltage alternating-current vacuum load switch-fuse combination("combination"for short)is used in powersystems with an AC frequency of 50 Hz and a rated voltage of 40.5 kV to break load currents,overload currents and short-circuit currents.Itparticularly applies to the places needing control,protection for oil-free,maintenance-free,frequently-operated and ring network power supplyunits and terminal power supply transformers.
The combination is characterized by large breaking capacity,high safety and stability,long electrical life,support for frequent operation,lessmaintenance,etc.It has an apparent isolating gap,an earthing switch with making capability,an electric spring actuator and remote controlcapability.
Product standards
FZ(R)N21 indoor load switch is produced in line with the following standards and codes.
●GB 16926-1997 High-voltage alternating-current load switch-fuse combinations
●IEC 60420 High-voltage alternating-current load switch-fuse combinations
Operating conditions
Normal operating conditions
●Ambient temperature:-40℃~+40℃(below 35℃ within 24 hours)
●Relative humidity:≤95%(daily average)or≤90%(monthly average)
Altitude:≤1000m
Technical parameters
| ltem | Unit | Reference value | ||
| Rated voltage | kV | 40.5 | ||
| Rated frequency | Hz | 50 | ||
| Rated maximum current of the fuse | A | 63 | ||
| 1min power-frequency withstand voltage | kV | Vacuum gap,interpole,pole-to-ground:95;isolating gap:110 | ||
| Insulation level Lightning impulse withstand voltage | kV | Vacuum gap,interpole,pole-to-ground:185;isolating gap:215 | ||
| Rated peak withstand current | kA | 50 | ||
| 4s rated short-time withstand current | kA | 20 | ||
| Rated breaking current of the active load | A | 1250 | ||
| Rated closed-loop breaking current | A | 1250 | ||
| Rated breaking current of cable during charge | A | 21 | ||
| Rated short-circuit breaking current | kA | 31.5 | ||
| Rated transfer current | A | 1200 | ||
| Fuse mode | XRNT3A-40.5/□-31.5 | |||
| Output energy of the fuse striker | J | 2-5 | ||
| Rated short-circuit making current | kA | 80(expected peak value) | ||
| Rated peak withstand current of the earthing switch | kA | 50 | ||
| 4s rated short-time withstand current of the earthing switch | kA | 20 | ||
| Rated voltage (DC or AC)of the auxiliary circuit | V | 220;110 | ||
| Mechanical life | Cycles | 10000 | ||
Technical parameters of the vacuum load switch
| ltem | Unit | Reference value |
| Gap of contacts | mm | 17±1 |
| Compression travel of the contact spring | mm | 4±1 |
| Average making speed | m/s | 0.6±0.2 |
| Average breaking speed(gap:6mm) | m/s | 1.5±0.2 |
| Breaking time | ms | ≤60 |
| Non-synchronous making/breaking of contacts of the three phases | ms | ≤2 |
| Bounce time in contact making | ms | ≤3 |
| Distance between live parts and phase-to-ground distance | mm | ≥300 |
| Circuit resistance between the upper and lower brackets | μ Q | ≤80 |
Overall and Installation dimension
Overall dimension of FZ(R)N21-40.5 indoor high-voltage altenating-current vacuum load switch(side installation and left hand operation)
L:distance between the actuator and the frame (it is usually 330mm,or 430mm or 530mm upon request of the user.)
Overall dimension of FZRN21-40.5 load switch(side installation and left hand operation)
L:distance between the actuator and the frame (it is usually 330mm,or 430mm or 530mm upon request of the user.)
