Product Overview

The JDZ-3/6/10(W) and JDZF-10 indoor semi-enclosed epoxy cast-resin voltage transformers are medium-voltage voltage transformers designed for 3kV, 6kV and 10kV AC power systems. They convert primary system voltage into standardized secondary voltage signals for voltage measurement, energy metering, monitoring instruments and relay protection circuits.

This series adopts a semi-enclosed cast-resin structure. The transformer core and windings are insulated with epoxy resin, while the primary terminals, secondary terminals and mounting structure are arranged for indoor switchgear installation.

JDZ JDZF 3 6 10W Current Transformer AD image

Application Position

The JDZ / JDZF voltage transformer is normally installed inside indoor medium-voltage switchgear, metering panels or voltage transformer compartments. It supplies secondary voltage signals to voltmeters, energy meters, protection relays, monitoring devices and control systems.

Main Applications

3kV, 6kV and 10kV indoor medium-voltage switchgear
Voltage metering and voltage indication circuits
Energy metering and power monitoring systems
Relay protection voltage input circuits
Single-phase voltage measurement in medium-voltage distribution systems
Cabinet applications requiring semi-enclosed epoxy cast-resin insulation

Key Specifications

Item	Specification
Model series	JDZ-3(W) / JDZ-6(W) / JDZ-10(W) / JDZF-10
Product type	Indoor voltage transformer / potential transformer
Structure	Semi-enclosed type
Insulation structure	Epoxy cast-resin insulation
Installation	Indoor
Rated voltage class	3kV, 6kV and 10kV
Rated frequency	50Hz
Rated secondary voltage	100V, or dual-secondary output according to model
Accuracy class	0.2, 0.5, 1, 3 and dual-secondary accuracy combinations
Main function	Voltage metering, monitoring and relay protection

Application Fit

Suitable For

Indoor medium-voltage switchgear rated 3kV, 6kV or 10kV
Voltage metering circuits requiring 100V secondary output
General voltage indication and monitoring circuits
Relay protection circuits requiring voltage reference signals
Projects requiring semi-enclosed epoxy cast-resin voltage transformers

Not Recommended For

Outdoor exposed installation without a protective enclosure
Systems above the specified rated insulation level
Applications requiring fully enclosed cast-resin or oil-immersed VT construction
Special voltage ratios, dual-secondary arrangements or accuracy classes without technical confirmation

Technical Structure

Component	Description
Core	Ring-type iron core used for electromagnetic voltage transformation
Windings	Primary and secondary windings cast with epoxy resin insulation
Insulation body	Semi-enclosed epoxy cast-resin structure for indoor medium-voltage use
Primary terminals	High-voltage terminals arranged on the upper part of the transformer body
Secondary terminals	Secondary lead-out terminals arranged on the cast-resin base
Mounting base	Base-mounted structure for indoor switchgear installation

Model Designation

JDZ-3/6/10(W) / JDZF-10 Indoor Semi-Enclosed Epoxy Cast-Resin PT Product Type

The JDZ / JDZF model code can be interpreted as follows:

Code	Meaning
J	Voltage transformer
D	Single-phase structure
Z	Epoxy cast-resin insulation
F	Special structural variant / product variant code used in JDZF models
3 / 6 / 10	Rated voltage class: 3kV, 6kV or 10kV
W	Anti-pollution / product variant code according to manufacturer specification

Technical Data

The following technical data is based on the provided JDZ-3(W), JDZ-6(W), JDZ-10(W) and JDZF-10 sample tables. Final values should be confirmed according to the approved drawing, technical agreement and nameplate data.

JDZ Technical Data

Item	JDZ-3(W)	JDZ-6(W)	JDZ-10(W)
Rated voltage ratio (V)	1000/100 2000/100 3000/100	6000/100	10000/100
Frequency (Hz)	50	50	50
Rated output for accuracy class 0.5 (VA)	30	50	80
Rated output for accuracy class 1 (VA)	50	80	150
Rated output for accuracy class 3 (VA)	80	200	300
Max. output (VA)	200	400	500
Rated insulation level (kV)	3.5/23/40	6.9/32/60	11.5/42/75

JDZF-10 Technical Data

Type

Voltage

Ratio (V)

Frequency

(Hz)

Output

0.2 Class

(VA)

Output

0.5 Class

(VA)

Output

0.2/0.2 Class

(VA)

Output

0.5/0.5

Class (VA)

Max.

Output

(VA)

Insulation

Level

(kV)

JDZF-10(W)

10000/100

25/25

50/50

200

11.5/42/75

Technical notes:

The product is designed for indoor use in 50Hz medium-voltage systems.
Voltage ratios and secondary outputs should be selected according to the connected meter or relay input requirement.
Dual-secondary output configurations should be confirmed before ordering.
Final rated output and accuracy class should follow the nameplate and technical agreement.

Service Conditions

Altitude: not over 1000m
Ambient temperature: maximum +40°C, minimum -5°C
Relative humidity: less than 85% at 20°C
The product has passed direct vibration testing with an intensity of 0.4g three-sine waves according to the product sample statement.
The product can be used under pollution conditions according to the sample description.
Installation environment should be indoor and suitable for medium-voltage cast-resin equipment.

Installation and Dimensions

The JDZ / JDZF series should be installed according to the approved outline drawing, wiring diagram and switchgear layout. The sample drawings show several structure options for JDZ-3 / JDZ-6, JDZ-10 standard type, JDZ-10L increased-capacity type and JDZF-10L dual-secondary increased-capacity type.

Dimension and Weight

Model / Structure	Typical Application	Approximate Weight
JDZ-3 / JDZ-6	3kV or 6kV semi-enclosed cast-resin VT	19.5 kg
JDZ-10	10kV, 10000/100V, 0.5 class standard type	25 kg
JDZ-10L	10kV, 10000/100V, 0.2 class increased-capacity type	31 kg
JDZF-10L	10kV, 10000/100/220V dual-secondary increased-capacity type	31 kg

Terminal and Wiring Notes

Primary wiring and secondary wiring should follow the approved wiring diagram.
Single-phase connection and three-phase connection options should be selected according to the project design.
Secondary terminal markings must be checked before commissioning.
The transformer should be firmly fixed to the cabinet base or mounting plate.
Electrical clearance and creepage distance should comply with the rated insulation level and switchgear design.

Compliance and Testing

The JDZ / JDZF semi-enclosed cast-resin voltage transformer series is designed for indoor medium-voltage applications. Applicable standards, inspection items and acceptance criteria should be confirmed according to the project specification, customer requirements and final technical agreement.

Typical Routine Tests

Visual inspection and nameplate verification
Ratio verification
Polarity and terminal marking check
Accuracy test at specified rated burden
Power-frequency withstand voltage test
Insulation resistance test
Secondary winding verification

Engineering Notes

Select the model according to system voltage: JDZ-3, JDZ-6 or JDZ-10.
Select JDZF-10 where a special dual-secondary or higher-accuracy metering configuration is required.
Do not exceed the rated output corresponding to the selected accuracy class.
Confirm whether the circuit uses single-phase or three-phase connection before wiring.
Verify terminal markings, grounding arrangement and insulation clearance before commissioning.
For special ratios, special capacity or special environmental conditions, technical confirmation is required before ordering.

Selection Guide

How to Select the Correct JDZ or JDZF Model

Select JDZ-3(W) for 3kV systems, JDZ-6(W) for 6kV systems and JDZ-10(W) for 10kV systems. Select JDZF-10(W) when the project requires a 10kV dual-secondary or special metering configuration.

How to Select Accuracy Class and Rated Output

Use class 0.5 or 0.2 for higher-accuracy metering circuits, class 1 for general measurement and class 3 for indication or lower-accuracy auxiliary circuits. The rated output should be higher than the total connected burden of meters, relays and wiring.

How to Confirm Voltage Ratio

The primary voltage ratio should match the system voltage, such as 1000/100V, 2000/100V, 3000/100V, 6000/100V or 10000/100V. The secondary voltage should match the input rating of the connected instrument or relay.

How to Confirm Installation Space

Check the outline drawing, base mounting holes, terminal direction, bushing clearance and weight before cabinet installation. Increased-capacity or dual-secondary models may require different installation space.

Ordering Information

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

Product model: JDZ-3(W), JDZ-6(W), JDZ-10(W), JDZF-10(W), JDZ-10L or JDZF-10L
Rated voltage ratio and secondary voltage requirement
Rated frequency: normally 50Hz
Required accuracy class and rated output
Single-secondary or dual-secondary configuration
Rated insulation level
Installation dimensions or switchgear layout requirements
Applicable standard or project specification
Quantity
Special requirements for drawings, test reports, certificates, nameplate language, packaging or shipping

FAQs

The JDZ-3/6/10(W) voltage transformer is used to convert 3kV, 6kV or 10kV primary voltage into standardized secondary voltage signals for voltage metering, voltage monitoring and relay protection in indoor medium-voltage systems.

Semi-enclosed cast-resin structure means the core and windings are insulated with epoxy resin, while the primary and secondary connection parts are arranged for indoor cabinet installation. It is different from fully enclosed cast-resin structures and oil-immersed structures.

Select JDZ-3(W) for 3kV systems, JDZ-6(W) for 6kV systems and JDZ-10(W) for 10kV systems. JDZF-10(W) can be selected for special 10kV metering configurations, including dual-secondary output requirements.

Select the accuracy class according to the circuit function. Metering circuits normally use 0.2 or 0.5 class, general measurement may use class 1, and indication circuits may use class 3. The rated output should be higher than the total connected secondary burden.

JDZ-10 is the standard 10kV semi-enclosed voltage transformer type. JDZF-10 is used where a special secondary configuration, such as dual-secondary output or higher-accuracy metering arrangement, is required. The final configuration should be confirmed by technical specification.

No. This series is designed for indoor use. Outdoor exposed installation requires an outdoor voltage transformer structure or a suitable enclosure confirmed by the project design.

Check altitude, ambient temperature, humidity, switchgear space, mounting holes, terminal direction, bushing clearance and rated insulation level before installation. The standard service condition is indoor use with altitude not over 1000m.

Typical routine tests include ratio verification, polarity check, terminal marking check, accuracy test at rated burden, power-frequency withstand voltage test, insulation resistance test and secondary winding verification.

Please provide the model, voltage ratio, rated frequency, accuracy class, rated output, insulation level, secondary configuration, installation dimensions, applicable standard, quantity and any requirements for drawings, certificates, test reports, nameplate language or packaging.