Back to smartelemfg Home
Contact us Merchants settle in
Back to smartelemfg Home
Home -PT protection relay
GWZC-9851 PT protection relay
PT protection relay Side View
PT protection relay Rear View
GWZC-9851 PT protection relay
PT protection relay Side View
PT protection relay Rear View
GWZC-9851 PT protection relay

Applicable Scope:The GWZC-9851 PT Protection Relay is designed for voltage transformer (PT) protection and monitoring in 110kV and below substations. It provides overvoltage and undervoltage protection for busbar PTs and is typically installed in switchgear cabinets for reliable voltage measurement in distribution and industrial power systems.

Product functions(ANSI): 59 | 27 | 59N | IEC 61850: XCBR.AlmCCS/MMXU.AlmPTFF

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

          The ​GWZC-9851 PT Protection Relay​ is designed for voltage transformer (PT) protection and monitoring in ​110kV and below​ substations. It provides ​overvoltage, undervoltage, and fuse failure protection​ for busbar PTs and is typically installed in ​switchgear cabinets​ for reliable voltage measurement and fault detection in distribution and industrial power systems.

Product functionsANSI)

​1.Overvoltage Protection (ANSI 59)
2.Undervoltage Protection (ANSI 27)
3.Zero-sequence Overvoltage Protection (ANSI 59N)
4.Control Circuit Supervision Alarm (IEC 61850: XCBR.AlmCCS)
5.VT Fuse Failure Alarm (IEC 61850: MMXU.AlmPTFF)

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)

Related products More
GWZC-9651 VT (Voltage Transformer) Protection Relay
GWZC-9651 VT (Voltage Transformer) Protection Relay
detail
GWZC-9852 PT Paralleling relay
GWZC-9852 PT synchronizing relay
detail
GOWE-9000 Partial discharge online monitoring system
Partial discharge online monitoring system
detail
GOWE-9000 Wireless Temperature Monitoring System for Substations
detail
GWZC-9604 Feeder Arc Flash Protection Relay
GWZC-9604 Feeder Arc Flash Protection Relay
detail
Technical Knowledge More
Wireless Temperature Monitoring System for Substations
Wireless Temperature Monitoring System: Application in Switchgear​
This article introduces the application of wireless temperature monitoring systems in high-voltage and low-voltage switchgear. The configuration of the wireless temperature monitoring system varies across different equipment. If you need a customized wireless temperature monitoring solution for your project, please visit our website for more information.
2025/09/08
GWZC-9804 Arc Flash Protection Relay
Switchgear Arc Flash Protection System Configuration Scheme
This article introduces the configuration scheme for a switchgear arc flash protection system. Busbar arc flash protection monitors the busbar compartment and trips the incoming breaker, while feeder arc flash protection monitors the circuit breaker compartment and cable compartment to trip the feeder breaker. A proper arc flash protection system configuration scheme can effectively protect personnel and equipment safety. For information on a reliable arc flash protection system configuration scheme, please visit our website.
2025/09/04
Arc Flash Protection Relay
Arc Protection Working Principle and Decision Process
Arc Flash Protection is a specialized safety system engineered to rapidly detect and mitigate destructive electrical arc flash faults. Unlike conventional overcurrent protection, it utilizes a combination of light and current sensors to identify an arc flash event within milliseconds. By triggering a circuit breaker to isolate the fault incredibly fast, Arc Flash Protection significantly reduces the explosive energy released, safeguarding personnel from severe injury and preventing extensive damage to electrical equipment like switchgear. This makes it an indispensable defense layer in industrial, commercial, and utility power systems.
2025/09/03
GWZC-9851 PT protection relay
PT protection relay Side View
PT protection relay Rear View
Inquiry Consultation
产品表单
Inquiry Consultation
+86-17621210051
+86-17621210051
+86-17621210051
+86-17621210051
home product email
live chat
my