🔍 Transformer Overview
| Field | Value | Explanation |
|---|---|---|
| Type of Phase | 3Ø | 3-phase transformer |
| Connection Type | AN | Likely manufacturer’s internal code (not standard notation) |
| KVA Rating | 300 KVA | Transformer capacity: can handle 300,000 VA (or 300 kVA) |
| Primary Voltage | 380 / 400 / 420 V | Input voltage (star-connected) — selectable based on tap |
| Secondary Voltage | 60 V | Output voltage (delta-connected) — for furnace heater circuits |
| Primary Current | 456 / 433 / 412 A | Current drawn at respective primary voltages (depends on tap selected) |
| Secondary Current | 2887 A | Very high current — furnace heaters draw large current at low voltage |
| Impedance | Not specified here (normally %Z) | Usually shows short circuit impedance (not printed here) |
| Frequency | 50 / 60 Hz | Operates on standard utility frequency (India = 50 Hz) |
| Cooling Type | Air Cooled | Natural air cooling — no oil or fan system |
| Vector Group | Yd11 | Y = star primary, d = delta secondary, 11 = 330° phase shift |
🧮 Vector Group: Yd11
- Primary winding: Star (Y)
- Secondary winding: Delta (d)
- Phase Shift: 11 o’clock position → 330° shift
Used in applications like furnaces where:
- Load needs low voltage, high current
- Isolation and phase shift are useful
🧊 Cooling Info
| Field | Value |
|---|---|
| Cooling Type | Air Cooled |
| Core & Winding | 1023 Kg |
| Total Mass | 1388 Kg |
This is a dry-type transformer, cooled by natural air. Total mass includes casing, terminals, etc.
🏷️ Markings & Terminals
➤ Primary (STAR-connected):
- Voltage taps: 380V, 400V, 420V
- Neutral available
- Used for 3-phase power input
➤ Secondary (DELTA-connected):
- Output voltage: 60 V between phases
- No neutral — only line-line available
- Suited for heaters in delta
🏭 Application Fit:
This transformer is specially built for industrial furnaces:
| Feature | Purpose |
|---|---|
| 🔥 Low voltage, high current (60 V / 2887 A) | To supply power to resistive heating elements |
| 🧊 Air cooled | Easy to maintain, ideal for indoor control rooms |
| 🔄 Delta secondary | Perfect for 3-phase heater bank in delta |
| 🛡️ Yd11 vector | Helps isolate furnace system from supply and reduce harmonics impact |
✅ Summary:
- 300 kVA air-cooled transformer
- Primary: 380–420 V star
- Secondary: 60 V delta, high current (2887 A)
- Used to power 3-phase delta-connected heaters in a vacuum furnace
- Vector group Yd11 ensures isolation and controlled phase shift