10.4 Standby Equipment
This part of the Energy Efficiency Manual shows how to eliminate the waste of energy that occurs from unnecessary operation of duplicate equipment. In many systems, reserve or standby units are installed for the sake of reliability. This is common practice in pumping systems, and it occurs less commonly in systems of many other types. The installation of duplicate or spare components is likely to waste energy unless you install a reliable method to prevent the unnecessary operation of duplicate equipment. For example, energy waste is common with spare pumps in HVAC systems because operators are not sure of how many pumps to operate.
There is a simple and reliable way to prevent this energy waste: connect power to the equipment so that only the proper number of units can receive power simultaneously. Where only two units of equipment are installed, a transfer switch is the simplest method. Where more than two units are installed, a rotary switch is the simplest approach. Here you will learn the details of this simple, inexpensive, and powerful energy conservation measure.