Product Introduction:
The GWZC-9821C Transformer Differential Protection Relay is a specialized protection device designed for medium to high-voltage power transformers in substations, industrial plants, and renewable energy systems. It provides differential protection by comparing currents on both sides of the transformer to detect internal faults such as winding short-circuits, while harmonic restraint prevents false tripping during inrush conditions. Additional features may include CT supervision and backup overcurrent protection. Typically installed in transformer protection panels, control cubicles, or high-voltage switchgear, this relay ensures reliable fault detection while maintaining stability during transients, making it ideal for safeguarding critical transformers in utility and industrial applications.
Product functionsANSI）：
1.Instantaneous Differential Protection (ANSI 87H)
2.Percentage Differential Protection (ANSI 87)
3.Differential Current Alarm (ANSI 87AL)
4.Overcurrent Protection (Stage I/II/III) (ANSI 50/51)
5.Inverse Time Overcurrent Protection (ANSI 51V)
6.Overload Protection (ANSI 49)
7.Negative Sequence Overcurrent (Stage I) (ANSI 46)
8.Negative Sequence Overcurrent (Stage II) (ANSI 46)
9.Zero-Sequence Overcurrent (Stage I/II) (ANSI 50N/51N)
10.Zero-Sequence Overcurrent (Stage III) (ANSI 51N)
11.Overvoltage Protection (ANSI 59)
12.Undervoltage Protection (ANSI 27)
13.Zero-Sequence Overvoltage (ANSI 59N)
14.PT Fuse Failure (ANSI 60FL)
15.PT Loss of Voltage (ANSI 60)
16.CT Open-Circuit Detection (ANSI 60CT)
17.Control Circuit Supervision (ANSI 74)
18.Loss of Mains Protection (ANSI 27D)
19.Non-Electrical Protection (ANSI 30)
Electrical Specifications
Power Supply:
● AC: 85-264V, 47-63Hz (≤15% THD)
● DC: 100-370V (≤5% ripple)
Rated AC Parameters:
● Voltage: 100V/√3 or 100V
● Current: 5A/1A
● Frequency: 50Hz
Overload Capacity:
● Current Circuit: 2×In continuous | 10×In (10s) | 40×In (1s)
● Voltage Circuit: 1.5×Un continuous
Power Consumption:
● Supply: <10W (static), ≤15W (trip)
● Current Circuit: ≤1VA/phase (5A) / ≤0.5VA/phase (1A)
● Voltage Circuit: ≤0.5VA/phase
Digital Output:
● Dry contact (8A@250VAC / 30VDC)
● Dielectric: 4kVAC (coil-contact), 1kVAC (open contact)
● Operating Time: 5ms (typ) / 8ms (max)
● Mechanical Life: 100k operations
Protection Performance
Operating Range:
● Voltage: 0.5-120V (phase)
● Current: 0.02-20×In
● Zero-Seq Current: 0.05-20A
● Frequency: 35-65Hz | Delay: 0-100s
Accuracy:
● Voltage/Current: ±2.5% or ±0.1V/±0.05A (whichever greater)
● Frequency: ±0.01Hz
● Settings: ±2.5%
Trip Time:
● Instantaneous: ≤35ms (≥1.2× setting)
● Time-Delayed: ≤1% of setting or 35ms
Measurement & Monitoring
Range:
● Voltage: 0.5-120V | Current: 0.02-1.2×In
Accuracy:
● V/I: ±0.2% | Frequency: ±0.01Hz | Other: 0.5%
● Time Sync: ≤2ms | SOE: ≤1ms
Event Recording:
● 128 protection trips/operations
● 32 self-tests/fault waveforms (COMTRADE)
Environmental & Mechanical
Operating Temp:
● Standard: -10°C to +55°C
● Extended: -40°C to +70°C*
Storage Temp: -40°C to +80°C
Humidity: 5-90% RH (non-condensing)
Pressure: 60-110 kPa
Compliance:
● IEC 60255-21 (vibration/shock)
● IEC 61000-6 (EMC)
