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GWZC-9890L Low-Frequency Low-Voltage Load Shedding DeviceGWZC-9890L Low-Frequency Low-Voltage Load Shedding Device
Low-Frequency Low-Voltage Load Shedding Device Side View
Low-Frequency Low-Voltage Load Shedding Device Rear View
GWZC-9890L Low-Frequency Low-Voltage Load Shedding DeviceGWZC-9890L Low-Frequency Low-Voltage Load Shedding Device
Low-Frequency Low-Voltage Load Shedding Device Side View
Low-Frequency Low-Voltage Load Shedding Device Rear View
GWZC-9890L Low-Frequency Low-Voltage Load Shedding Device
Applicable Scope:GWZC-9890L Underfrequency and Undervoltage Load Shedding (UFUVLS) device serves as an emergency protection measure for power systems. It automatically sheds partial loads to restore balance when grid frequency drops due to power deficit or voltage declines from reactive power deficiency, preventing frequency collapse or voltage instability while avoiding widespread blackouts. This device is particularly suitable for complex grids with high renewable energy penetration.
Product functions(ANSI):IEEE C37.2: ​27L1, 27L2, 27L3  | 59L1, 59L2, 59L3 | 81L1, 81L2, 81L3 | ​81O1, 81O2, 81O3
Communication functions:Supported Protocols:​​IEC 60870-5-103 (over Ethernet) | MODBUS RTU (via RS-485) | IEC 61850 (Ed.2 or Ed.1, as applicable)
​Interfaces:​​2× Ethernet Ports​ (IEEE 802.3 compliant, 10/100 Mbps) | 2× RS-485 Ports​ (ANSI/TIA-485-A standard, galvanically isolated)
Other functions: Support time synchronization via communication message, SNTP (Simple Network Time Protocol) time synchronization, and IRIG-B time synchronization. Support the dot matrix printing function with serial port communication. Support the fault recording function
Product Introduction Technical Parameter Size

Product Introduction:

          GWZC-9890L Underfrequency and Undervoltage Load Shedding (UFUVLS) device serves as an emergency protection measure for power systems. It automatically sheds partial loads to restore balance when grid frequency drops due to power deficit or voltage declines from reactive power deficiency, preventing frequency collapse or voltage instability while avoiding widespread blackouts. This device is particularly suitable for complex grids with high renewable energy penetration.

Product functions(ANSI):

Undervoltage Load Shedding ( ​27L1, 27L2, 27L3)
Overvoltage Load Shedding ( ​59L1, 59L2, 59L3)​
Underfrequency Load Shedding (81L1, 81L2, 81L3)
Overfrequency Load Shedding (81O1, 81O2, 81O3)
PT Fuse Failure Alarm (60)

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)

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GWZC-9890L Low-Frequency Low-Voltage Load Shedding DeviceGWZC-9890L Low-Frequency Low-Voltage Load Shedding Device
Low-Frequency Low-Voltage Load Shedding Device Side View
Low-Frequency Low-Voltage Load Shedding Device Rear View
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