Transformers transfer electrical energy between circuits and are used differently in various industries, mainly for adjusting voltage. For example, they can step down voltage for low-voltage equipment or step up voltage for long-distance power transmission.

When buying a transformer, it's important to consider carefully and check its specifications for optimal and efficient functions. Here are key factors for selection:

1. Phase Number

Before choosing a transformer type, determine the equipment's application and type. Single-phase transformers are common in household appliances, while three-phase ones are for large enterprises with heavy loads. Manufacturers list compatible phase numbers and equipment types in manuals, which you should refer to for a proper match.

2. Operating Environment

The operating environment matters a lot in transformer selection. Its parameters should fit the environment for stable operation. In open areas exposed to weather, liquid-filled or oil-cooled transformers are better as they protect windings from weather risks like humidity and temperature changes. For dry-type transformers in harsh environments like salty air and high temperatures, anti-corrosion paint coatings are needed to ensure stability and a long service life.

3. Power Characteristics and Protection

Ideally (ignoring losses), the KVA on the primary and secondary sides of a transformer is equal. But in reality, transformers have losses, mainly copper losses (from winding resistance when current passes through, related to load current square) and iron losses (from the iron core in an alternating magnetic field, mostly unrelated to load).

Since transformers are costly, preventive measures are necessary for good operation and a long lifespan. These include using corrosion-resistant coatings, installing oil level and pressure monitors, choosing hot-dip galvanized radiators, and having temperature and pressure control with trip and alarm functions to handle abnormal situations and ensure stable operation.