A single-line diagram (also known as an SLD or one-line diagram) is a drawing that charts out the electrical sources, components, and connections in a power distribution system.
How Do Single-Line Diagrams Work?
The electrical components, or nodes, in these diagrams are represented by standardized schematic symbols. Nodes are arranged vertically from top to bottom. The top of the diagram marks the beginning of the flow of electricity and the nodes at the top typically represent power sources such as the utility feed, generator, or battery.
As you progress down the single-line diagram, you can follow the flow of power to other equipment downstream.
How Do Data Centers Use Single-Line Diagrams?
In data centers, single-line diagrams are used to visualize the complete power path. This simplifies planning, troubleshooting, and maintenance to help maintain uptime and increase efficiency. The vertical orientation of these diagrams also enables data center managers to easily see redundant power paths side-by-side.
The equipment that a data center typically tracks with a single-line diagram includes:
- Utility feed. The main power source from the utility.
- Generators and fuel tanks that deliver backup power during an outage.
- Transformers that convert electrical power from one voltage or current to another voltage or current.
- Switchgears that control, protects, and isolates electrical equipment.
- Switchboards that divide and distribute power into branch circuits.
- Automatic transfer switches (ATS) that switch to a backup power source when there is an outage.
- Uninterruptible power supply (UPS) units that provide emergency power during an outage until the power returns or a longer-term backup system turns on.
- Floor power distribution units (PDUs) that transform raw power feeds into lower capacity feeds that feed into remote power panels or busways and rack PDUs.
- DC power plants that provide uninterrupted DC power.
- DC bays that divide and distribute individual loads from the DC power plant to equipment downstream.
Traditional vs. Modern Single-Line Diagrams
In a data center, a single-line diagram is typically printed on paper and hung on a wall somewhere.
The common challenges of using paper diagrams include:
- Limited accessibility for remote teams
- Lack of real-time information
- Poor version control
- No integration with digital tools
- Difficult to share, review, and provide feedback on
However, there is a new way forward with Data Center Infrastructure Management (DCIM) software.
Modern DCIM software offers automatic, dynamic, and interactive single-line diagrams that dramatically simplify data center management.
DCIM software provides centralized management of all your data center assets and supporting infrastructure equipment and maps their relationships and dependencies for you. The single-line diagrams are automatically generated based on the items and connections in the tool’s database. Any change you make is immediately reflected in the diagram, ensuring its accuracy.
The single-line diagram feature in modern DCIM software offers significant advantages over traditional static diagrams. It enables the overlay of real-time power and capacity data, facilitating easier management of data center power. This capability supports both AC and DC power chains, enabling visualization and detailed analysis of utility feeds, generators, fuel tanks, transformers, load devices, UPS units, AC panels, floor PDUs, DC power plants, and DC bays.
With DCIM software, you can track the electrical characteristics and interconnections within your power chain. Each node includes a detailed panel displaying budgeted and actual values for voltage, current, power rating, highest/lowest phase, and more so you can easily understand your capacity and load at any point in the power chain.
The single-line diagrams are easily navigable, editable via drag-and-drop, and printable.
Want to see how Sunbird’s leading DCIM software automates single-line diagrams? Get your free test drive now!
