Distribution Systems
EasyPower supports the following types of distribution systems:
- 3-phase 3-wire (3PH-3W): Phases A, B, and C as current-carrying conductors.
- 3-phase 4-wire (3PH-4W): Phases A, B, C, and neutral as current-carrying conductors.
- 1-phase 2-wire (1PH-2W): This could be line-to-neutral or line-to-line conductors.
- 1-phase 3-wire (1PH-3W): Two line-conductors and a center-tapped neutral.
EasyPower versions prior to 10.4 supported only 3-phase systems. Single-phase connections can originate at a 3-phase distribution system or at single-phase sources.
From a 3-phase system you can make the following 1-phase connections:
- Line-to-line: AB, BC, CA.
- Line-to-neutral: AN, BN, or CN.
Figure 1: 3-Phase Distribution
While making single-phase connections to 3-phase equipment, you need to determine if a line-to-neutral connection is possible. The program does not automatically prevent you from making line-to-neutral connections on 3PH-3W systems.
1PH-3W Systems
A 1PH-3W (one-phase, three-wire) system represents a distribution system that has a grounded neutral center-tap connection and two line (hot or live) conductors. The two line conductors have voltage angle that is 180 degrees apart from each other. This system is typically derived from a center-tapped single-phase transformer or a generator.
From a 1PH-3W system, you can make the following connections:
- LLN: This is a 1PH-3W system with two line-conductors with opposite polarity and a center-tapped neutral conductor.
- L1N: This is a 1PH-2W system with the first line conductor and a neutral conductor.
- L2N: This is a 1PH-2W with the second line conductor and a neutral conductor.
- LL: This has two line conductors and no presence of a center-tapped neutral.
Figure 2: 1PH-3W Distribution
A 1PH-3W system can originate at the following equipment:
- A single-phase transformer with a center-tap connection.
- Sources with a 1PH-3W service (a generator, inverter, or UPS).
Figure 3: Transformer and Generator Connection Information
Single-Phase Service Selection
The dialogs boxes for single-phase buses, panels, ATS, and sources have an option called Service. You can select the service to be 1PH-2W or 1PH-3W. This property can be changed only when the equipment is disconnected from other equipment.
Figure 4: Single-Phase Service Selection
