The wires extending from the secondaries or
distribution transformer to a customer's location are called a
service. A service can be above or below ground. Underground services
have a riser connection at the distribution pole. Commercial and residential
services are much the same and can be either 120 or 220 or both.
Figure 1. Distribution system lines and associated equipment
Figure 2. Service line to residence
Figure 3. Commercial service
Figure 4. Secondary to underground service via a riser