Overview

The JDG4-0.5 Indoor Low Voltage Transformer is a dry-type transformer designed for indoor applications in power systems with a rated voltage of 0.5kV and a frequency of 50Hz. Built with a durable thermosetting phenolic plastic framework and high-quality cold-rolled silicon steel cores, it ensures precise voltage measurement, energy metering, and relay protection. This transformer complies with GB1207 and IEC60044-2:2003 standards, making it reliable for low-voltage applications.

The JDG4-0.5 Indoor Low Voltage Transformer is engineered for accuracy and safety, ideal for use in measuring instruments and protective relay systems. Its compact and robust design prevents overloads and provides dependable operation in harsh indoor environments, ensuring efficient and secure system performance.

Type Designation

The following is an explanation of the product designation:

• J: Voltage transformer
• D: Single phase
• G: Dry type
• 4: Design number
• 0.5: Voltage grade (kV)

Operating and Installation Conditions

1. Installation Location: Indoor.
2. Ambient Temperature: -5°C to +40°C.
3. Ambient Humidity: Relative humidity not exceeding 80%.
4. Altitude: Not exceeding 1000 meters.
5. Atmospheric Conditions: Free from severe pollution or contamination.

Construction of JDG4-0.5 Voltage Transformer

The core of the JDG4-0.5 Voltage Transformer is constructed using high-quality cold-rolled silicon steel sheets in a “C”-shaped design. The primary and secondary windings are mounted on the middle columns of two “C”-shaped cores. All terminal connections are routed to a secure wiring pedestal, ensuring efficient and safe operation. Overload operation is strictly prohibited, reinforcing the reliability and longevity of the transformer.

Technical Data for

Outline and Dimensions of Installation

JDG4-0.5 Indoor Low Voltage Transformer Dimensions of Installation

JDG4-0.5 Indoor Low Voltage Transformer Dimensions of Installation

Connection Methods for Voltage Transformers

The connection methods for voltage transformers can be categorized into the following three common types:

1. Star Connection (Y-Y): In systems where the neutral point is ungrounded or grounded through an arc suppression coil, the PT’s primary winding must be connected in a star configuration with the neutral grounded. This setup is used to measure the phase-to-ground voltage.
2. V-V Connection: Two single-phase transformers are connected to the UAB and UBC line voltages in the power grid, forming an incomplete delta configuration (also known as V-V connection). This method is widely used in ungrounded or arc suppression coil-grounded networks below 20kV to measure the inter-phase voltages. However, it cannot measure the phase-to-ground voltage.
3. Open Delta Connection: Three single-phase, three-winding voltage transformers form either YN, yn, d11 or YN, y, d11 connections (where the secondary star winding’s neutral is grounded via the B-phase). This method is widely applied across all voltage levels, especially in 3~15kV systems. The secondary winding is used to measure inter-phase or phase-to-ground voltages. The auxiliary secondary winding is configured as an open delta to connect insulation monitoring instruments, relays for ungrounded networks, or ground protection systems for directly grounded systems.

When ordering, please specify the following:

1. Insulation level
2. Ratio of primary and secondary voltage
3. Number of cores, output, and accuracy class
4. Test specification
5. For special customizations, please contact us

FAQs for JDG4-0.5 Indoor Low Voltage Transformer

1. What are the primary applications of the JDG4-0.5 Voltage Transformer?
   The JDG4-0.5 is ideal for voltage measurement, energy metering, and relay protection in low-voltage indoor power systems with a rated voltage of 0.5kV.
2. What standards does the JDG4-0.5 Voltage Transformer comply with?
   It complies with GB1207 and IEC60044-2:2003 standards, ensuring safety and performance for industrial and utility applications.
3. Can the JDG4-0.5 Voltage Transformer be used outdoors?
   No, it is designed exclusively for indoor use in controlled environments.
4. What is the rated output and limit output of the JDG4-0.5 Voltage Transformer?
   It has a rated output of 15 VA and a limit output of 25 VA for voltage ratios of 220/100, 380/100, and 500/100.
5. What should be specified when ordering the JDG4-0.5 Voltage Transformer?
   Please specify the insulation level, primary-to-secondary voltage ratio, number of cores, rated output, accuracy class, and any required test specifications.
6. Can the JDG4-0.5 Voltage Transformer be customized for specific requirements?
   Yes, special customizations are available. Please contact our technical team to discuss your specific needs.