Generators with sealed windings in weather-protected enclosures can replace totally enclosed machines at a reduced overall cost and with improved performance.
Smaller and lighter: Because generators with weather-protected enclosures do not require a secondary air exchange, they are smaller and lighter. Typical output derating ranges from 30 to 40 percent of open drip proof construction to make a synchronous machine totally enclosed. For example, in the 4,000 kW rating, the totally enclosed machine requires a one size larger frame than the open machine.
Less complicated: Weather-protected enclosures are less complicated than totally enclosed designs. This is important during servicing. In some cases, replacing the bearing on a totally enclosed machine may require removing the entire cooler assembly with brackets.
No enclosure seals to rely on: With totally enclosed designs, seals (such as those used to seal the shaft, lead entrance, and terminal boxes) will eventually wear out and cause environmental contamination, leading to more costly disassembly for cleaning.
Features: Kato generators with weather-protected enclosures and sealed windings are designed and manufactured for an expected service life of 20 years. These generators will provide excellent service in adverse environments.