Structure and Meaning of Transformer Model Symbols
Dry-type transformer Symbols models typically consist of a combination of letters and numbers, each representing specific technical characteristics. Below is an example and breakdown:
- SCB10-1000KVA/10KV/0.4KV:
- S: Three-phase transformer (D indicates single-phase).
- C: Cast resin solid insulation.
- B: Foil winding (R represents wire winding; L indicates aluminum winding).
- 10: Design sequence number, where higher numbers denote newer technology.
- 1000KVA: Rated capacity.
- 10KV/0.4KV: Primary and secondary rated voltage.
Other letter arrangement order and meaning of Dry-Type Transformer Symbols
(1) Winding coupling method: ** (not marked); self-coupling (indicated by O).
(2) Number of phases: single phase (D); three phase (S).
(3) Winding external insulation medium: transformer oil (not marked); air (G); gas (Q); molded solid casting type (C); wrapping type (CR); flame retardant liquid (R).
(4) Type of cooling device: natural circulation cooling device (not marked); air cooler (F); water cooler (S).
(5) Oil circulation method: natural circulation (not marked); forced oil circulation (P).
(6) Number of windings: double winding (not marked); triple winding (S); double split winding (F).
(7) Voltage regulation method: no-excitation voltage regulation (not marked); on-load voltage regulation (Z).
(8) Coil conductor material: copper (not specified); copper foil (B); aluminum (L); aluminum foil (LB).
(9) Core material: electrical steel sheet (not specified); amorphous alloy (H).
(10) Special purpose or special structure: sealed (M); series connection (C); starting (Q); lightning protection (B); capacity adjustment (T); high impedance (K); ground station traction (QY); low noise (Z); cable lead-out (L); isolation (G); capacitor compensation (RB); oil field power lighting (Y); plant transformer (CY); fully insulated (J); synchronous motor excitation (LC).
Technical Features Behind the Symbols
- Insulation Type:
- Cast resin type (C): Excellent fire resistance, suitable for indoor use.
- Non-encapsulated type (G): High-temperature tolerance, ideal for industrial environments.
- Cooling Methods:
- Natural cooling (AN): No additional equipment required, suitable for general applications.
- Forced air cooling (AF): Uses fans for heat dissipation, ideal for high-load conditions.
- Winding Material:
- Copper winding (no specific symbol): Superior conductivity, lower losses.
- Aluminum winding (L): Cost-effective but slightly higher losses.
Connection Method Dry-Type Transformer Symbols Explanation
The connection method of dry-type transformers is often represented by codes like “Dyn11.” Below is a breakdown of common symbols:
| Symbol | Meaning | Features |
|---|---|---|
| Y | Star connection | Includes neutral point, suitable for three-phase four-wire systems |
| D | Delta connection | No neutral point, ideal for balanced loads |
| n | Neutral point lead-out | Provides zero line |
| 11 | Clock notation | Secondary voltage leads primary voltage by 30° |
Quick Guide to Nameplate Information
The nameplate on a dry-type transformer contains essential parameters that help buyers understand its performance:
- Rated Capacity: For example, “1000KVA” indicates the maximum load capacity.
- Primary/Secondary Voltage: For example, “10KV/0.4KV,” which specifies input and output voltage ranges.
- Frequency: Typically “50Hz” or “60Hz.”
- Insulation Class: For example, “F-class” or “H-class,” indicating heat resistance levels.
Application Scenarios and Selection Tips
Choose the right product based on symbols:
- For high-rise buildings, hospitals, or other locations requiring high safety standards, opt for SCB series cast resin transformers.
- For industrial equipment or high-load environments, select models with AF cooling methods for enhanced performance.
