ELECTRICAL DESIGN OF INSTALLATION

The electrical design and planning of the on---site generation system is critical for proper system operation and reliability. This chapter covers installation design of the generator and related electrical systems, their interface with the facility, and topics regarding load and generator protection.

The electrical installation of the generator set and its accessories must follow the Electrical Code in use by local inspection authorities.

Electrical installation should be done by skilled, qualified, and experienced electricians/contractors.
Electrical System Designs tend to vary considerably based on the needs, or primary functions of the power generation equipment in the application. A system design that is optimized for emergency service situations will generally not be the best fit for interruptible service and is definitely not the same type of system design as a prime power application.

The one---line configuration differences are easy to see. For example, in prime applications the generator sets are at the ”top” of the distribution system while in standby and especially in emergency applications the generator sets are connected to loads toward the ”bottom” of the distribution system.

Power transfer points in prime applications tend to be at the top of the distribution, switching large blocks of load, often with circuit breaker pairs while emergency and standby systems often utilize transfer switches located further down in the system.

Other differences are more subtle. Protection in a standby system is minimized in favor of greater reliability while in prime power we tend to move toward greater emphasis on protection of equipment. Coordination is often more of a concern in emergency applications. In standby applications grouping of loads might be commonly done based on location of loads within the facility, while in emergency applications, the grouping is based on priority of service.

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