K-WANG



Chapter 1 General Information and Hardware Specifications
1. Classification of core functions of the whole machine
(1) Complete set of protective components (ANSI standard)
Fixed time overcurrent 51P (phase)/51N (neutral): 12 standard delay curves (S/L/D/M/I/V/E/A/B/C/G/F, including BS142 national standard curve), supporting integral reset;
Instantaneous overcurrent 50P/50N;
Fixed time overcurrent 50TP/50TN;
Low frequency load shedding 81 (low-frequency trip+frequency recovery automatic coincidence);
Undervoltage protection 27, overvoltage protection 59;
Circuit breaker failure protection BF;
Locking function: BT1 locks neutral overcurrent, BT2 locks all fixed time overcurrent.
(2) Automatic reclosing 79
Up to 4 times of overlapping delay for gear division, configured with coincidence failure timer, total cycle timer, and reset timer; Support segmented timing with downstream sectionalizers/fuses, equipped with voltage loss locking and external switching control.
(3) Measurement and data recording
Real time measurement: three-phase current/neutral current, three-phase voltage, frequency, active/reactive/apparent power, power factor;
Demand statistics: maximum/minimum current and power demand within the 1-60 minute interval;
Electricity measurement: cumulative active/reactive hours;
Fault storage: up to 40 fault events with time stamps (10ms resolution), recording fault type, current and voltage, circuit breaker action, and set value group;
Life statistics of circuit breakers: cumulative breaking times, cumulative I ² t.
(4) 4 independent fixed value groups
Normal standard, Aux1 cooling load, Aux2 emergency, Aux3/Aux4 special working conditions; External switch value switching setting, Aux2 has the highest priority, and the cooling load mode can be automatically activated.
(5) IO and Communication Resources
Input: Multiple switch values (reclosing/locking/circuit breaker position/user programmable input);
Output: 2-channel tripping, 2-channel closing, circuit breaker failure output BLTC voltage tap changer lockout, 7-channel fault target relay, multi-channel programmable alarm;
Communication: Front panel RS232, backplane RS232/optional RS485, VT100 terminal protocol, supports parameter upload and download, remote monitoring.
2. Electrical hardware parameters
CT/PT adaptation: supports 1A and 5A secondary currents; PT secondary 60-130V, supports three-phase three wire Delta/three-phase four wire Y connection switching;
Working power supply: 48Vdc/125Vdc/120Vac, optional dual redundant power supply;
Contact capacity: Trip contact short-term 30A (0.2s), continuous 3A; resistive load 250Vdc 0.3A;
Environment: Operating at -40 ℃~+70 ℃, resistant to vibration and impact, 95% no condensation humidity;
Storage life: Built in lithium battery clock, non-volatile storage with a maximum of 100000 erasures;
Mechanical: 19 inch 5U rack, supporting horizontal/vertical installation, equipped with a dedicated testing simulator.
3. Model coding rules
The model letter distinguishes CT secondary (1A/5A), power supply type, whether it has underfrequency/undervoltage, testing module, horizontal and vertical installation, and communication interface.
4. 12 types of overcurrent delay curves
Built in BS142 standard curves for short, long, standard, extreme, super, timed, and four types, with complete curve charts, calculation formulas, and constant tables.
Chapter 2 Panel Controls and Module Structure
The whole machine is divided into 3 detachable panel modules:
Control module: single line 12 character display screen, up and down selection buttons, status reset, LED indicator lights (overcurrent/coincidence/frequency/voltage/fault self-test, etc.); Split state mode, fixed value editing mode, and automatic locking of reclosing in editing mode.
Contact detection module: test mode push-pull switch, 15 test sockets, circuit breaker position indicator lights 5a/52 b, power indicator light, mechanical fault target indicator (TRIP1/TRIP2, manual reset); The test mode can isolate external circuits and inject analog signals.
Magnetic transformation module: Built in CT/PT isolation transformer, panel can be opened to replace wiring plugs, built-in Y/Δ voltage connection switch.
Two operating modes
Status mode (default power on): Loop view real-time current, voltage, frequency, demand, fault target, time and date;
Fixed value mode: Only the front panel can modify basic parameters (CT ratio, baud rate, demand cycle, time), all protection curves, coincidence logic, and programmable IO require external terminal modification; Modifications that are not saved can be revoked.

Chapter 3 Detailed Functional Principles
1. Simulation acquisition and signal circuit
Three phase+neutral current, three-phase voltage are isolated and sampled by an AD converter, and digital filtering is used to suppress DC offset and harmonics of more than 2 times, thereby improving the sensitivity of ground fault protection; Support two-phase/three-phase power algorithms.
2. Logic of various protective actions
Overcurrent protection (50/51/50T)
51 inverse time limit: optional integral reset, distinguishing phase/neutral independent curves;
50 instantaneous: quick break protection, no delay;
50T fixed time limit: independently set delay, can be locked by BT1/BT2 external contacts.
Voltage protection 27 undervoltage/59 overvoltage
Phase separation detection, fixed time limit; It can be switched on or off separately, and automatically locks to prevent PT disconnection and misoperation below the set threshold.
Low frequency 81 protection
Low frequency delay tripping, automatic coincidence after frequency recovery; Set the minimum voltage lockout, PT will not operate when power is lost, and the delay can be independently adjusted.
Circuit breaker failure BF
After the protection trip output, if the circuit breaker is not disconnected and the current continues, the delay triggers the BFI failure output and trips the upstream power supply. Simultaneously monitor the integrity of the trip circuit and issue a disconnection alarm.
3. Four stage automatic reclosing 79
1-4 independent adjustable delays, configuration:
RI coincidence allowed, RDS coincidence prohibited, DTL forced locking permanent disconnection external contacts;
Segmented timing coordination: The downstream protection first cuts off the fault, and this device detects the disappearance of current and automatically counts a coincidence;
BLTC output: After a fault trip, lock the on load tap changer of the substation and release it after restoring normal operation.
4. Fixed value group switching logic
External switch triggers 4 sets of fixed values, Aux1 cooling load can be automatically put into operation after a long period of voltage loss, Aux2 emergency mode has the highest priority; When switching, the recloser will immediately lock and disconnect.
5. IO programmable function
5-way user-defined input: event triggering, target reset, constant value switching, demand reset, etc;
Multi channel programmable alarm output: power failure, reclosing, circuit breaker abnormality, protection action, communication failure, etc., can be connected to SCADA.
6. Communication function
Front and rear RS232 are mutually exclusive, with the front panel taking priority; Support ASCII terminal interaction, parameter upload/download, and fault record export; Set multi-level passwords to prevent illegal modifications and capture terminal logs to save files.
Chapter 4 Installation Specifications
Installation method: 19 inch rack horizontal/vertical installation, provide opening and external dimension drawings; The equipment casing must be reliably grounded (grounding terminal 25).
Wiring requirements: The terminals should be compatible with cables of 12AWG and below, distinguishing between AC CT/PT, DC control power supply, tripping and closing, and communication terminals;
Voltage withstand test: The maximum voltage withstand of the complete cabinet is 1500Vac, and the device has a coupling capacitor inside. There is a small leakage current during voltage withstand;
Optional test plug: unplug the original wiring plug, replace the test plug, isolate the primary and secondary circuits for offline verification;
Isolation transformer configuration: When the PT secondary does not match, an external isolation transformer should be connected, and the three-phase three wire/four wire should be wired according to the drawing.
Chapter 5 Complete Testing Process of the Whole Machine
1. Specialized testing simulator
Equipped with BE1-DFPR test bench, simulate all switch inputs with status indicator lights, provide complete schematic diagram, and standard wiring diagram for bench testing.
2. Standardized verification steps
Preparation in advance: power on, simulate circuit breaker closing, and connect the tripping circuit monitoring;
Clock settings: Modify the date and time on the panel, verify the battery time when powered off;
Fixed value operation: Modify panel basic parameters, configure complete terminal protection logic, support loading factory default fixed values;
Single point verification of each protective component: 51/50/50T overcurrent, 27 undervoltage, 59 overvoltage, 81 low frequency, apply analog quantities item by item, verify action values and error ranges;
Delay verification: Verify the time limit of each protection action, the delay of each section of reclosing, and the delay of failure one by one;
Switching test: BT1/BT2 lockout, reclosing switch DTL、 52 circuit breaker position, user programmable input;
Output contact verification: tripping, closing, BFI failure BLTC、 Each alarm target relay;
Whole machine self-test mode: One click traversal of all LEDs and output contacts, quickly troubleshooting hardware faults;
Trip special test and demand data reset function test.
Chapter 6 Maintenance Instructions
Daily: Regular functional testing only, no need for daily maintenance; The lifespan of the clock lithium battery is about 10 years, and it should be replaced upon expiration;
2. Internal maintenance: There are no easily replaceable discrete components, and it is recommended to return to the factory for repair if there is a malfunction; After replacing the board by oneself, it must be retested completely;
3 Storage requirements: Store below 40 ℃, power on for 30 minutes per year to extend the lifespan of electrolytic capacitors, and reduce the lifespan of capacitors in high-temperature environments by half.

K-JIANG
Add: Jimei North Road, Jimei District, Xiamen, Fujian, China
Tell:+86-15305925923