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Distribution Systems: Distribution Transformers

Distribution Transformers
Distribution transformers reduce the voltage of the primary circuit to the voltage required by customers. This voltage varies and is usually:
  • 120/240 volts single phase for residential customers,
     
  • 480Y/277 or 208Y/120 for commercial or light industry customers.
Three-phase pad mounted transformers are used with an underground primary circuit and three single-phase pole type transformers for overhead service.

Network service can be provided for areas with large concentrations of businesses. These are usually transformers installed in an underground vault. Power is then sent via underground cables to the separate customers.

Figure 1. Air Distribution transformer - commercial facility
Figure 1. Air Distribution transformer - commercial facility
 		 Figure 2. Industrial facility distribution transformer
Figure 2. Industrial facility distribution transformer
Figure 3. Residential distribution transformer
Figure 3. Residential distribution transformer		 Figure 4. Pad-mounted residential distribution transformer
Figure 4. Pad-mounted residential distribution transformer
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Occupational Safety & Health Administration
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