LZW-72.5 Outdoor Current Transformer

Product Overview

LZW-72.5 current transformer, epoxy resin casting insulation and outdoor installation, is widely used for measuring current, electric energy and protective relaying in the power system with the rated frequency 50Hz or 60 Hz and rated voltage 66kV or 69kV.

Key Features

• High-Voltage Grade Outdoor-Specific Design：The LZW-72.5 features a 72.5kV rated voltage design with insulation levels reaching 125kV (lightning impulse) / 70kV (power frequency withstand voltage). It strictly complies with GB/T 4703.2 and IEC 60044-2 standards, optimized for high-voltage outdoor scenarios such as 110kV and below outdoor substations and overhead lines. This ensures safe and stable operation in long-term high-voltage environments, effectively reducing the risk of insulation breakdown.

•  Extreme Climate Protection Structure：The product incorporates a triple protection system: it uses silicone rubber composite insulation materials and aluminum alloy flanges, achieving 10,000 hours of UV aging resistance; reaches IP68+ protection, enabling long-term operation at 2 meters underwater, with special designs to withstand 30mm/h snow accumulation and ice loads up to 20mm thickness; passes 3,000 hours of salt spray testing, with a creepage distance of 31mm/kV, fully meeting the requirements of harsh outdoor environments such as plateaus, extreme cold, and coastal areas.

• Dual-Winding High-Precision Measurement System：The LZW-72.5 integrates a 0.2S-class metering winding and a 5P30-class protection winding. The metering winding maintains a ratio error ≤±0.2% within 1%~120% rated current, meeting high-precision energy metering needs; the protection winding has a composite error ≤5% at 30 times rated current with 8ms fast response, effectively ensuring the speed of relay protection devices. It includes 3 sets of ratio taps (e.g., 600/5A, 800/5A, 1000/5A), which can be flexibly adjusted via an outdoor-specific sealed switch without disassembly to adapt to different load current scenarios.

• Intelligent Condition Monitoring and Communication Technology:The product is equipped with multi-parameter sensors for temperature (-40℃~+120℃), humidity, and insulation dielectric loss, collecting real-time operational data. It supports IEC 61850-9-2 digital protocol and DL/T 645 standard, while retaining a 4~20mA analog output interface, enabling seamless integration into smart substation systems or compatibility with old monitoring equipment. In-depth analysis of historical data through cloud platforms predicts insulation aging trends in advance, providing data support for operation and maintenance decisions and significantly reducing outdoor inspection frequency and costs.

Main technical parameter

• Rated voltage : 66kV or 69kV

• Highest voltage for equipment : 72.5 kV

• Rated insulation level : 72.5/140/325kV

• Rated secondary current :5Aor1A

• Standards: IEC60044-1.2003 Part 1: Instrument transformers-Part1: Current transformers or ANSI IEEE STD C57.13-2008

Other technical parameter pls see as follow:

Double ratios

Remarks: Upon request we are glad to offer transformers according to other standards or with non-standard technical specs.

Outline drawing