Three Phase Distribution Transformer
The choices that matter on a three phase unit are the vector group, the impedance, the winding material and the cooling method.
Almost all industrial and commercial power distribution is three phase. A three phase distribution transformer is a single unit containing three windings on a common core — more compact, more efficient and cheaper per kVA than a bank of three single phase units.
The choices that matter on a three phase unit are the vector group, the impedance, the winding material and the cooling method. Get these wrong and you get circulating currents, nuisance protection operation or a transformer that cannot be paralleled with the existing one.
Technical Specifications
| Parameter | Typical Value |
|---|---|
| Rated capacity | 500 – 3150 kVA |
| Primary voltage | 11 kV / 22 kV / 33 kV |
| Secondary voltage | 400 V / 415 V |
| Phase | Three phase |
| Frequency | 50 Hz or 60 Hz |
| Vector group | Dyn11 standard; Dyn5, Yyn0, YNd11 on request |
| Impedance | 4% – 6% |
| Cooling | ONAN / KNAN / AN / AF |
| Winding material | Copper or aluminium |
| Neutral | Solidly earthed or resistance earthed as specified |
| Standards | IEC 60076 / IEEE C57.12 |
Typical values for this product family. Insert your certified datasheet values before publication — Hebei Youge Electrical Equipment Co., Ltd..
Applications
- Three phase motor loads
- Factory distribution boards
- HVAC and chiller plant
- Lift and escalator supplies
- Commercial riser distribution
- Mixed single and three phase building loads
Advantages
- Single compact unit instead of a three-unit bank
- Lower losses and better voltage regulation
- Correct vector group for paralleling with existing plant
- Balanced neutral design for mixed lighting and power loads
- Copper or aluminium to match project budget
- Full routine testing including ratio, vector group and insulation
Customization Options
- Vector group and earthing arrangement
- Impedance to suit fault level and paralleling
- Copper or aluminium windings
- Cable box arrangement: top or bottom entry
- Monitoring and alarm contacts
Manufacturing, Testing and Standards
Every unit is built under documented process control and subjected to routine tests before dispatch: winding resistance, voltage ratio and vector group, impedance voltage and load loss, no-load loss and current, applied and induced voltage dielectric tests, and functional checks of accessories. Type tests — including lightning impulse, temperature rise and short-circuit withstand — are available for new designs and project requirements. See our testing and quality control pages.