Model meaning
Z: vacuum arc extinguishing
N: indoor installation
23: Design serial number
12: Rated voltage (kV)
Functional localization
Full current interruption: reliably interrupt rated current, overload current and short circuit current (up to 31.5kA).
Fast protection: the opening time is less than ≤50ms, and the fault cutting speed is better than the traditional model.
Typical application
Inlet/outlet of 12kV distribution system, distribution room of industrial and mining enterprises, box-type substation (adapted to XGN15-12, KYN28A-12 and other switchgear).
Operation accessory configuration
Operating power supply: DC 110V/220V or AC 220V V.
Auxiliary contact: 6 normally open+6 normally closed (including energy storage/on/off indication)
Locking function
It is forbidden to push/pull the handcart in the closing state.
The earthing switch is mechanically interlocked with the circuit breaker.
Type selection verification formula
Thermal stability check: I \ infty} 2 \ CDOTT \ LEQ I _ {th} 2 \ CDOT4I ∞ 2t ≤ ITH24 (fault thermal effect ≤ circuit breaker tolerance).
Altitude correction: when it is more than 1000m, the capacity will be reduced by 1% per 100m rated current.
Ambient temperature: -30℃-+40℃ (special design is required if it exceeds the range).
Critical threshold
Break-brake speed is 1.1 0.1 m/s (if the speed drops by more than 15%, it needs maintenance).
Contact overtravel is 3 0.5 mm (< 2.5 mm, the arcing chamber must be replaced).
Periodic maintenance
3 years /5000 operations:
Main circuit resistance measurement (standard: ≤ 40μ ω @ 1250a)
Mechanism lubrication (special low temperature grease)
Forced replacement of arc extinguishing chamber
Cumulative breaking short-circuit current reaches 300% Isc (for example, 25kA cumulative breaking 75kA).
Used for 10 years (even if the parameters are normal)
Iron law of safe operation
Five-proof interlock must be intact!
After breaking the brake, you must wait for ≥15s before operating the handcart (to ensure that the arc is completely extinguished).
