Picking the Power Distribution Solutions Suited for Your Needs

Electrical power is easy to understand. Electricity enters the building where it passes through a supply point for delivery to the lights, appliances, computers, and other devices that make your building a modern facility. However, it’s not always as simple as Point A to Point B. In fact, there are many types of power distribution solutions that you can adopt to maximize efficiency and reliability.

The Basic Arrangements

There are four basic circuit arrangements:

• Radial
• Primary Selective
• Secondary Selective
• Secondary Network

Radial

Radial systems are the simplest and least costly to set up. These receive power at the utility supply voltage, from which point the voltage is stepped down to the required level of utilization.

Primary Selective

Primary selective systems involve the use of two primary main breakers coupled with a primary tiebreaker. These can be mechanically or electrically interlocked to prohibit parallel operation. If either side loses the primary voltage source, it can be transferred either manually or automatically until power is restored.

Secondary Selective

Secondary selective systems operate similarly. However, in a secondary selective system, two transformers are connected via a double-ended substation arrangement that is interlocked mechanically or electrically, again to prohibit parallel operation. The loads can be automatically or manually transferred to restore power to secondary loads if power loss occurs.

Secondary Network

Secondary network systems offer superior reliability and continuity. These involve the use of multiple utility services that are paralleled together at low voltage. Secondary network systems will not fail if a fault anywhere in the primary system occurs. This is due to the fact that the circuit breakers installed at the transformer isolate faults and are then back-fed through the system, thus clearing the fault without disrupting service.

Additional Options

In addition to the four basic configurations, there are many other types of configurations to choose from. These include:

• Composite Systems
• Sparing Transformer Systems
• Primary Loop Systems
• Expanded Radial Systems

Composite systems

Composite systems involve using multiple types of configurations. This option is desirable when a facility requires two or more arrangements. But, this type of reliability is more expensive to install, plus the increased complexity of composite systems requires greater attention to maintenance.

Sparing transformer systems

Sparing transformer systems are essentially scaled-up cousins of secondary selective systems. These use single-ended substations coupled with one or multiple transformer substations that are connected on a common secondary bus. This gives remarkable flexibility and makes it easy to switch between transformers in the event of a failure.

Primary loop systems

Primary loop systems have two or more transformers connected together on a loop. Within primary loop systems, the sectionalization of switches means that parallel operation is prohibited. If one loop goes down, it is switched to the alternate loop to accommodate the loss and keep your systems operational.

Expanded radial systems

Expanded radial systems are simple, easy to expand, and can incorporate multiple substations to achieve exceptional reliability. Better than expanded radial systems, those with primary selectivity offer superior reliability. Because expanded radial systems do cause a temporary loss of power when switching, radial systems with primary selectivity do not because the transformers can be paralleled to prevent any loss of power.

Are you working to determine which power distribution solutions are best suited for your operations? Contact Central Power Systems and Services at (816) 781-8070, and we will be happy to answer your questions and help you determine the best solution for your business.