Overview

This type of high-voltage combined transformer is improved on the basis of similar products and is cast from imported outdoor special insulation resin from abroad. It has the characteristics of arc resistance, ultraviolet resistance, aging resistance, and long life. It is suitable for metering of active and reactive power in AC power systems with a rated frequency of 50HZ and a rated current of 35KV. It is especially suitable for small substations with unattended and oil-free products. The product performance meets GB requirements.

Model and meaning

Structure introduction

The combined transformer consists of three single-phase voltage transformers (PT) and three current transformers (CT); the voltage transformer and current transformer are vacuum casted into one by a special outdoor insulation material (Swiss CibaCW5837). It is small in size and has the characteristics of high thermal stability, high precision, low magnetic density, overvoltage resistance, light weight, and easy installation. The secondary winding of the current transformer has taps to obtain different current ratios.

The secondary outlet terminal has a wiring protection box, and there is a wiring hole below it, which is convenient to connect, safe and reliable, and can prevent power theft. There are four mounting holes on the base channel steel for installation.

Technical data

This type of combined transformer reference standard

GB/T 20840.1-2010 "Transformers Part 1: General Technical Requirements"

GB/T 20840.4-2015 "Transformer Part 4: Technical Requirements for Supplementary Combined Transformer"

Rated voltage: 35kV

Rated frequency: 50Hz

Rated insulation level: 40.5/95/200 kV  

Rated voltage ratio: 35/√3/0.1/√3kV

Rated primary current: 5~600A; Rated secondary current: 5A or 1A

Rated capacity: PT: 0.2 level, 3×20/30VA; CT: 0.2S level, 3×15VA

Rated short-term thermal current (Ith) multiple: 100In/Is

Rated dynamic stable current (Idyn) multiple: 2.5Ith

Rated load power factor: cosФ=0.8 (hysteresis), FS≤10

Ambient temperature: between -25℃ and 40℃, the average daily temperature shall not exceed 35℃

Dirt level: Level IV

Altitude: no more than 1000m

Wiring diagram   

Appearance and installation dimensions

When installing a resonator on the N-terminal, the resonator must use weak insulation (D type) product.

Ordering instructions

1. Current ratio

2. Secondary cable length

3. Other special requirements

Things to note

1. After wiring, check whether all wiring is correct, especially the voltage secondary outlets a-b and c-b, and the current secondary outlets xS1 and xS2 or xS3 cannot form an open circuit.

2. The base ground terminal must be grounded on the site, and the transformer secondary outlet wire is reliably connected to ground according to regulations. Please note that the double-variable current secondary terminals S2 and S3 cannot be grounded at the same time.

3. The primary line installation must be P1 as the incoming side and P2 as the outgoing side.

4. Pay attention to protecting the terminal board and umbrella group during handling and hoisting.