BH-0.66 II Indoor Plastic Case Current Transformer, low voltage distribution

BH-0.66 II Indoor Plastic Case Current Transformer, low voltage distribution

0.66kV indoor window-type current transformers for low-voltage distribution metering and current monitoring

  • Multiple rectangular window sizes available for busbar and cable installation
  • Rated 5A secondary output with 150A to 4000A primary current range
  • Indoor plastic case construction for low-voltage switchgear, distribution cabinets
  • Accuracy classes 0.5, 0.2, 0.2S & 0.5S for metering and monitoring circuits
  • For 50Hz AC systems up to 0.66kV, with -5°C to +40°C standard service

Product Overview

The BH-0.66 II indoor plastic case current transformer is a window-type low-voltage current transformer designed for current measurement, electrical monitoring, and energy metering circuits in AC distribution systems with rated voltage up to 0.66kV. The product converts primary current in a busbar or cable circuit into a standard 5A secondary current signal for meters, instruments, or monitoring equipment.

The BH-0.66 II series is mainly used in indoor low-voltage distribution cabinets, complete switchgear assemblies, metering panels, and industrial power distribution systems. The product adopts an enclosed plastic case structure and is available with multiple rectangular window apertures to match different busbar and cable layouts.

Product Type

Item Specification
Product name Indoor Plastic Case Current Transformer
Model series BH-0.66 II / BH(SDH)-0.66 II
Product structure Window-type / through-core current transformer
Rated voltage class 0.66kV low-voltage AC system
Rated frequency 50Hz
Installation location Indoor
Typical applications Metering, current monitoring, low-voltage distribution measurement, switchgear instrumentation

Product Display

BH-0.66 II indoor plastic case current transformer product display

Main Applications

  • Low-voltage AC distribution systems rated up to 0.66kV
  • 380V and 660V distribution cabinets
  • Low-voltage switchgear and complete distribution panels
  • Energy metering and current measurement circuits
  • Electrical monitoring systems for industrial and commercial power networks
  • Busbar or cable current sensing where a rectangular window-type CT is required

Key Technical Features

  • Window-type installation: The primary busbar or cable passes through the CT window, allowing direct current sensing without a primary winding connection.
  • Multiple aperture options: Window sizes include 30×30, 40×30, 50×30, 60×30, 80×30, 100×30, 120×50, 155×50, 180×50, 206×55, 225×50, and 225×65.
  • Standard 5A secondary current: Compatible with common metering instruments, low-voltage monitoring devices, and measuring circuits.
  • Indoor plastic case structure: The enclosed housing provides mechanical protection and electrical insulation for the internal core and winding assembly.
  • Low-voltage distribution design: Suitable for 50Hz AC circuits with rated voltage up to 0.66kV.

Working Principle

The BH-0.66 II current transformer operates based on electromagnetic induction. When the primary conductor passes through the window and carries current, magnetic flux is generated in the iron core. The secondary winding outputs a proportional 5A current signal for connected meters, instruments, or monitoring devices. This enables safe measurement of high primary current in low-voltage distribution circuits.

Model Designation

BH-0.66 II current transformer model designation

The model code can be interpreted as follows:

Code Meaning
SDH / BH Product series for low-voltage outgoing cabinet or enclosed current transformer application
0.66 Rated voltage class: 0.66kV
Window size code Maximum busbar or cable window width in mm
II Product category / design series

Technical Data

Item Specification
Rated voltage 0.66kV / 660V
Rated frequency 50Hz
Rated primary current 150A to 4000A, depending on selected current ratio and specification
Rated secondary current 5A
Accuracy class 0.5, 0.2, 0.2S, 0.5S; subject to selected ratio and order requirements
Rated output 5VA or 10VA according to specification
Ambient temperature -5°C to +40°C
Installation altitude ≤1000m under standard service conditions
Applicable standards GB/T 20840.1, GB/T 20840.2; IEC 61869-2 can be referenced according to project requirements

Rated Current, Accuracy and Output Reference

Rated Primary Current (A) Rated Secondary Current (A) Accuracy Class Rated Output (VA)
150, 200, 250 5 0.5 5
300, 400, 500, 600 5 0.2 5
800, 1000, 1500 5 0.2S 5
2000, 3000, 4000 5 0.5 / 0.5S 10

Note: Technical data outside the above range can be confirmed by technical agreement between manufacturer and purchaser.

Installation and Dimensions

The BH-0.66 II series provides multiple rectangular window sizes for different busbar or cable configurations. The following dimensions are for reference. Final dimensions should be confirmed with the approved drawing before cabinet design or batch ordering.

BH-0.66 II current transformer installation and dimensions

Available Window Sizes and Overall Dimensions

Model a b h A B H
BH0.66(II) 30×30 32 32 85 59 50 97
BH0.66(II) 40×30 42 32 89 79 46 105
BH0.66(II) 50×30 52 32 92 87 46 108
BH0.66(II) 60×30 61 32 96 102 46 112
BH0.66(II) 80×30 83 32 103 122 45 119
BH0.66(II) 100×30 102 32 108 141 49 124
BH0.66(II) 120×50 122 52 135 165 50 151
BH0.66(II) 155×50 155 52 145 202 49 161
BH0.66(II) 180×50 180 52 145 231 49 161
BH0.66(II) 206×55 206 55 148 252 50 164
BH0.66(II) 225×50 226 52 150 270 55 166
BH0.66(II) 225×65 226 65 170 270 55 186

Unit: mm. Final dimensions are subject to confirmed drawing and selected specification.

Service Conditions

  • Installation location: indoor
  • Ambient temperature: -5°C to +40°C
  • Relative humidity: not more than 80% under standard conditions
  • Altitude: not more than 1000m unless otherwise specified
  • Atmospheric condition: no serious pollution in the surrounding air
  • The installation environment should be free from severe vibration, conductive dust, corrosive gas, explosive medium, and heavy moisture.

Standards and Compliance

The BH-0.66 II series is designed according to low-voltage current transformer requirements and can be supplied with reference to GB/T 20840.1, GB/T 20840.2, and related project specifications. IEC 61869-2 requirements may be referenced when required by the project or technical agreement.

Installation and Safety Notes

  • Confirm the rated current ratio, accuracy class, burden, and window size before installation.
  • Ensure that the busbar or cable passes correctly through the CT window.
  • Connect the secondary terminals according to the marked polarity.
  • The secondary circuit of a current transformer must not be open-circuited when the primary circuit is energized.
  • Secondary wiring and grounding should follow the project wiring diagram and local electrical regulations.
  • Installation and maintenance should be carried out by qualified electrical personnel.

Ordering Information

Please provide the following information when ordering or requesting a quotation:

  • Product model: BH-0.66 II or BH(SDH)-0.66 II
  • Window size, such as 30×30, 80×30, 120×50, 225×65, etc.
  • Rated primary current and rated secondary current
  • Required accuracy class
  • Rated output / burden in VA
  • System frequency
  • Installation quantity
  • Special requirements for labels, terminal arrangement, drawings, inspection documents, certificates, or packaging

Selection Guidelines

  1. Confirm system voltage: Select this CT for low-voltage AC systems up to 0.66kV.
  2. Confirm primary current: Select the current ratio according to the normal operating current of the circuit.
  3. Confirm window size: Match the CT aperture with the busbar or cable size in the cabinet.
  4. Select accuracy class: Use 0.2 or 0.2S for higher metering requirements, and 0.5 or 0.5S for general measurement or monitoring applications.
  5. Check rated burden: The total burden of connected instruments, meters, and wiring should not exceed the CT rated output.
  6. Confirm installation space: Check the overall dimensions before switchgear layout or cabinet assembly.

FAQs

It is used to convert primary current into a standard 5A secondary current signal for metering, monitoring, and measurement in low-voltage distribution systems.

The BH-0.66 II series is suitable for low-voltage AC systems with rated voltage up to 0.66kV, including common 380V and 660V distribution applications.

The standard secondary current is 5A, which is compatible with common low-voltage metering instruments and monitoring devices.

The available primary current range is generally from 150A to 4000A, depending on the selected window size, current ratio, rated output, and technical specification.

Common accuracy classes include 0.5, 0.2, 0.2S, and 0.5S. The final class should be selected according to the metering, monitoring, or project accuracy requirement.

The primary current ratio should be selected according to the normal operating current of the circuit. The selected ratio should cover the expected load current and allow reasonable margin for load fluctuation.

Yes. The BH-0.66 II series includes multiple rectangular window sizes from 30×30 to 225×65 for different busbar and cable layouts.

This model is intended for indoor installation. Outdoor applications should use a current transformer structure designed for outdoor environmental conditions, including moisture, UV exposure, pollution, and temperature variation.

When the primary circuit is energized, the secondary circuit of a current transformer must not be open-circuited. An open secondary circuit may generate high voltage, damage insulation, and create safety risks for equipment and personnel.

Please provide the model, window size, current ratio, accuracy class, rated output or burden, system frequency, quantity, and any special requirements for labels, terminals, drawings, certificates, inspection documents, or packaging.