Voltage-Transformer Selection for a Defined 3–10 kV Duty

The JDZ(X)9-3,6,10Q(G) 10kV single-phase instrument transformer family is a full-operational-mode, indoor unit. As a rugged cast-resin voltage transformer, it is specifically intended for measurement duties on single-phase 3 kV, 6 kV, and 10 kV distribution circuits. A family designation is not a single universal configuration. Before specifying a unit, verify the complete model code, voltage ratio, secondary arrangement, accuracy class, burden, insulation level, wiring diagram, and applicable dimensional drawing against the approved project documents.

That distinction matters in tendering and panel engineering. A procurement description may identify the 10kV voltage transformer family, while the meter, relay, secondary wiring, cable burden, and earthing scheme establish the actual configuration needed. Treat the transformer as one interface in a measurement chain. The approved single-line and secondary wiring diagrams should determine how the selected single-phase instrument transformer connects with the rest of the system.

What the Published Model Groups Indicate

In the documented code, J identifies a voltage transformer, D identifies a single-phase unit, and Z identifies cast insulation. The bracketed X indicates a residual-voltage winding when fitted. The figures 3, 6, and 10 identify the kilovolt family. Q denotes full operational mode, and the bracketed G identifies all-insulation construction.

The JDZ9-xQ is listed without a residual-voltage winding. The JDZX9 voltage transformer (specifically JDZX9-xQ and JDZX9-xG) is listed with residual-voltage arrangements where the corresponding wiring configuration applies. If the project requires earth-fault or residual-voltage measurement, compare that requirement with the relevant JDZX9 documentation. If it does not, the applicable JDZ9-xQ information is the more appropriate starting point. An external interposing transformer, meter, or relay does not independently determine this unit’s ratio or winding arrangement.

Electrical Information to Confirm Against the Exact Code

Selecting the correct cast-resin voltage transformer requires evaluating precise electrical parameters. Please refer to the table below for published family information:

The source lists JDZ9-xQ standard outputs of 40 VA at class 0.2, 100 VA at class 0.5, 200 VA at class 1, and 240 VA at class 3, with a stated maximum of 500 VA. The four-winding JDZ9-10Q entry shows 20/20 and 20/30 VA plus 30/30 VA, with a stated maximum of 400/400 VA.

For the JDZX9 voltage transformer, the published entries show 30 VA at class 0.2, 80 VA at class 0.5, 180 VA at class 1, 500 VA at class 3, and 100 VA at 6P, with a stated maximum of 600 VA. JDZX9-xG entries show 30 VA at class 0.2, 60 VA at class 0.5, 180 VA at class 1, 500 VA at class 3, and 100 VA at 6P. These figures are configuration-specific. A blank or slash is not an available rating, and a maximum value alone is not a selection rule.

Features that Support a Controlled Specification Review

When evaluating this 10kV voltage transformer for your project, consider the following technical features:

• Cast-resin, single-phase construction: Documented for the indoor instrument-transformer family, providing robust insulation.
• Voltage-family choice: Allows precise selection against the actual 3 kV, 6 kV, or 10 kV circuit.
• Measurement classes: The published tables include 0.2, 0.5, 1, and 3 entries to meet various metering accuracy needs.
• Residual-voltage arrangements: Apply only to the corresponding documented JDZX9 groups, ensuring earth-fault protection capabilities.
• 6P listing: Is limited to the listed JDZX9 configurations and requires confirmation for protection circuits.

It is intuitive to assume that a higher voltage class or output figure automatically produces a better installation. It does not. The useful unit is the one whose rated ratio, burden, accuracy, insulation, and winding arrangement match the connected circuit. Where a system study considers transformer excitation current, obtain the data sheet for the complete selected code; that factor is not stated in the published family summary as a selectable configuration value.

Drawing, Panel, and Secondary-Interface Checks

Mechanical information must be used with the matching drawing for this single-phase instrument transformer. JDZX9-3, 6, and 10Q drawings list a 251±1 mm overall height, 154 mm body height, 345 mm base length, one M10 primary terminal, an M8 earth bolt, two Φ13 × 16 holes, and four Φ13 base holes at 315±0.5 mm centres. JDZ9-3, 6, 10Q and JDZX9-3, 6, 10G drawings list a 256±1 mm overall height, a 358 mm base length, 186 mm width, two M10 terminals at 175 mm spacing, an M8 earth bolt, and four Φ13 base holes at 270±0.5 mm centres.

Check terminal access, secondary cable routing, earth connection, mounting-hole centres, clearance, and the specified wiring figure as one exercise. OCR material visually identifies an HV terminal stud, cast-resin body, transparent terminal cover, brass mounting base, and accessible secondary-side studs. It does not establish a universal cabinet-rail mounting method, so the project drawing and panel interface must govern that decision.

Application Boundary and RFQ Checklist

The documented application for this cast-resin voltage transformer is single-phase voltage measurement in 3 kV, 6 kV, and 10 kV distribution circuits. JDZ9-xQ applies where no residual-voltage winding is required; JDZX9-xQ and JDZX9-xG apply only when the required arrangement matches the published winding information. A 110kv transformer project is not a reason to substitute this family: its voltage class and measurement role must match the approved design.

For a useful request for quotation, state the rated voltage, complete model group, ratio, winding count, required accuracy and output, residual-voltage requirement, wiring diagram, mounting drawing, standards category, and test scope. Add the panel interface, cable restrictions, earthing arrangement, and project schedule. The source lists MOQ 1, T/T terms, and delivery within 20 days after receipt of payment; reconfirm commercial terms before ordering.

Confirm the relevant standards category, edition, test scope, and local-grid requirements with the supplier and responsible authority. Zhejiang Jingyu Technology Co., Ltd. lists voltage, current, and zero-sequence instrument transformers in its product range. Request the exact data sheet and drawing for the 10kV voltage transformer, have the selected configuration reviewed by qualified engineering personnel, and verify secondary-circuit continuity and earthing before energization.