These days, designs are favoring higher total system capacities, larger generators at higher output voltages integrated into “campus-type” power distribution systems, and security. Review design approaches, lessons learned, and relevant codes.
In my experience, one of the trouble spots in project specifications is coordinating the control panels furnished with mechanical equipment with the standards that apply to the balance of electrical equipment on the project. Regardless of what you may include about NEMA enclosure types, short-circuit ratings, and other features, manufacturers tend to supply their standard control panel. The result is often an installation that cannot be verified to meet code or project requirements.
Microprocessor-based systems greatly increased the power and flexibility of BMS while lowering the cost of sophisticated control. A similar evolu-tion in electrical metering and protection devices has increased the amount of power system information available to building operators.
For motors in certain applications, the boilerplate approach to specification and design will get the system stopped because the motor won't start. Consider voltage, speed, and torque for these special instances, and follow along with the Case Of The Not-So-Centrifugal Pump Curve and the Case Of The Frequent Motor Failure to do some real-life motor- starting sleuthing. By Tim Coyle, P.E.
Leaning on experience and data from various K-12 cities and projects, the author pursues some less conventional design approaches. They may revolve around radiant heating and/or cooling, but depending on school size and other factors, the smart use of heat recovery, DOAS, and improved central plants could also put a project on the HVAC honor roll.