QDTB® Transformer

JMB-1/0.66/0.38

JMB Series • 1kVA • 0.66/0.38 kV

JMB-1/0.66/0.38 is a 1 kVA, 0.66/0.38 kV special/isolation/control transformer manufactured by Shandong Yaqing Electric Power Technology Co., Ltd. (QDTB) in Qingdao, China, designed and tested in accordance with IEC 60076, vector group Dyn11, short-circuit impedance 12%, approximate weight 10 kg. Available on FOB Qingdao terms; datasheet, routine test report and GA drawing issued with each unit.

Technical Specifications

JMB-1/0.66/0.38 technical specifications
ModelJMB-1/0.66/0.38
Rated Capacity1kVA
HV Voltage0.66 kV
LV Voltage0.38 kV
Frequency50 Hz
Vector GroupDyn11
Short-circuit Impedance12%
CoolingAN
InsulationH (180°C)
Temperature Rise65 K
No-load Loss20 W
Load Loss40 W
EfficiencyNational/industry standard
Weight10 kg
Dimensions140×130×150 mm
Applied StandardIEC 60076

Typical operating points

Calculated from this model’s nameplate losses (P₀ 20 W, P_k 40 W), u_k 12%, at power factor 0.9.

LoadOutput (kW)No-load loss (kW)Load loss (kW)Total loss (kW)Efficiency (%)Voltage regulation (%)
50%0.50.0200.0100.03093.754.36
75%0.70.0200.0220.04394.086.60
100%0.90.0200.0400.06093.758.89
125%1.10.0200.0630.08393.1711.22

Highest efficiency around 1 kVA (70.7% of rating) — β* = √(P₀ / P_k).

Product Image & Parameters

JMB - QDTB

Images are for illustration purposes only

JMB-1/0.66/0.38

JMB Series

Capacity
1kVA
HV Voltage
0.66kV
LV Voltage
0.38kV
Frequency
50Hz
Short-circuit impedance
12%
Cooling method
AN
Efficiency
National/industry standard
Applied standard
IEC 60076
Connection
Dyn11 (IEC)
Energy SavingLow Loss

TECHNICAL DRAWING

Model: JMB-1/0.66/0.38 | Type: Oil-immersed transformer | Capacity: 1 kVA

FRONT ELEVATION

Oil level1U1V1W2U2V2W2NTAPN.P.120mm150mm

ELECTRICAL SCHEMATIC

HV WINDING (Delta)1U1V1WLV WINDING (Star)2U2V2W2NDyn11 (IEC)

EFFICIENCY vs LOAD

90%95%98%99%0%25%50%75%100%≈99%load %efficiency %

SIDE VIEW

Oil level90mm

TOP VIEW

1U1V1W2U2V2W2N90mm

TERMINAL BLOCK

HV TERMINAL BLOCK1U1V1W1N1PELV TERMINAL BLOCK2U2V2W2N2PE2122Terminal block configurationTin-plated copper busbar

CORE & WINDING

OIL / TANKHV winding/bushingINSULATIONLV winding/bushingIron coreconcentric cross-section

Technical specifications

1. Model:JMB-1/0.66/0.38
2. Type:Oil-immersed transformer
3. Capacity:1 kVA
4. Frequency:50 Hz
5. HV voltage:0.66 kV
6. LV voltage:0.38 kV
7. HV current:0.87A
8. LV current:1.52A
9. Vector group:Dyn11 (IEC)
10. Impedance:12%
11. Insulation level:H (180°C)
12. Temperature rise:65K
13. No-load loss:20W
14. Load loss:40W
15. No-load current:5.5%
16. Cooling method:AN
17. Tap changer:±5% Single-tap
18. Standard:IEC 60076
19. Dimensions:140×130×150 mm
20. Weight:10kg
LEGEND:
Iron core
HV winding/bushing
LV winding/bushing
Dimension line

Product Description

1kVA, 3-phase isolation, dry-type transformer, 50Hz, primary 660V (HV 660V), secondary 380V (LV 380V), Standard, insulation H, impedance 4%

Related Keywords

JMB-1/0.66/0.38 isolation control transformer1kVA control transformerprimary 0.66kV secondary 0.38kVJMB machine tool safety transformer for CNC equipment

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Derived Ratings (calculated from the configuration)

The values below are computed from what you selected above. Anything that cannot be computed yet is shown as an em dash — never as zero.

Iₙ = S / (√3·U) · I_sc = 100·Iₙ / uₖ · S_sc = √3·U·I_sc · I_p = k·Iₖ

Inputs taken from the configuration
Capacity: — kVAfrom the configuration above
System voltage: not specified
Impedance voltage uₖ: not specified
Result
Rated current Iₙ—
Short-circuit current I_sc—
Short-circuit current I_sc—
Short-circuit power S_sc—
I_sc is calculated on the transformer impedance basis alone (system impedance neglected) — the same basis used in IEC 60076-5 short-circuit calculations.

Still required to complete the calculation: rated capacity S, impedance voltage uₖ, short-time or peak withstand current.

Per-model values (P0 / Pk / uₖ declared by the factory, losses, noise, temperature rise, dimensions, weight) are not in the product library: those rows stay at an em dash until the factory parameter sheet is supplied. An em dash means the value is unavailable — it is never rendered as zero.

Derived losses (from the selected efficiency grade + capacity)
No-load loss P0 (kW)—
Load loss Pk (kW)—

Read-only: no price factor, not part of the sum — the loss-grade cost is already carried by the efficiency (subtype) base price, so charging here would double-bill. Values come from the product library type-test data, interpolated between published capacities; grades the library does not cover show an em dash, never zero.

特种/隔离/控制变压器（产品库逐型号 noLoadLoss，无独立能效档维度）

Reference prices are for estimation only and do not constitute a formal offer.

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JMB-1/0.66/0.38 - Frequently Asked Questions

QWhat are the main applications of JMB-1/0.66/0.38?

JMB-1/0.66/0.38 (JMB series, Special/Isolation/Control Transformers) is widely used in industrial power distribution, commercial buildings and utility power systems. Can be flexibly configured according to actual project requirements.

QWhat are the main technical specifications of JMB-1/0.66/0.38?

Key specifications: Capacity: 1kVA, HV 0.66 kV, LV 0.38 kV, Frequency 50 Hz, Impedance 12%, Connection Dyn11 (IEC), Cooling AN, Standard IEC 60076.

QCan JMB-1/0.66/0.38 be custom ordered?

Yes. QDTB® provides comprehensive OEM/ODM customization services. Parameters such as capacity, voltage ratio, cooling method, connection group and protection class can all be adjusted. Over 25 years of manufacturing experience ensures consistent quality.

QHow to get a quote and technical documentation?

Contact via the "Send Inquiry" button below, or contact sales at Alice@qdtb-transformer.com / +86 13698683193. We provide detailed quotations and technical documentation instantly.

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