Introduction
Landscape Lighting transformers differ greatly in design, construction and performance. To demonstrate the importance of these differences, a team of electrical engineers were asked to compare two transformers that are commonly used in Landscape Lighting installations.

The transformers used for the study were the CAST "Master Series" 1200 watt transformer (CM1200SSMT) and a leading competitor's 1200 watt model. The CAST transformer utilizes a torroidal core while the competitor's model uses an EI type laminated core. The difference in the core type was the main factor responsible for differences found in the tests.

Testing Methods
The transformers were tested in an electrical engineering laboratory under identical conditions using standard testing methods. Transformers were first tested under no load then under full (1200 watts) load for each of the voltage taps between 12 volts and 17 volts. Testing under full load was conducted for 10 hours and 20 mins. Operating temperatures were observed and engineers inspected the transformers for suitability of materials used and made notes on possible points of failure.

Summary of Results
The CAST Transformer performed better in all tests demonstrated by the following results and calculations:

• 42% lower operating temperature
• 48% less average voltage drop on all taps under full load
• 10% less average amperage consumed under full load
• 95% less amperage consumed under no load
• 93% less core loss
• 3% better regulation
• 7% better efficiency

Charted Results

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Additional Notes

1. "No load" voltages on non-CAST Transformer are not consistent.
2. Regulation on non-CAST Transformer is not consistent from tap to tap.
3. Internal electrical components such as magnet wire and inrush protection circuit are open to weather and subject to corrosion and short circuits.