Active engine cool down time delay for automatic transfer switch controllers

#Concurrently filed herewith is patent application Method and Apparatus to Optimize Generator Start Delay and Runtime Following Outage, and patent application Method and Apparatus to Change Generator Start Delay and Runtime Following Outage, the disclosures of which are incorporated herein in their entirety.

#The disclosure relates generally to power systems and methods that employ generators for backup power to a facility, and more particularly, to a system, method, and controller for cooling a backup generator after use.

#Typically, electrical power is provided from a primary source (such as a utility or a “grid”) to facilities that include residential, small business, and industrial environments. However, occasionally the electrical power is interrupted for reasons that may include weather damage to power lines and equipment, power plant shutdowns (scheduled or not), and other sorts of system failures such as cascading plant failures. Although the grid can be generally stable over time and may operate uninterrupted for months or more, the possibility of lost power from the primary source is nevertheless ever-present and can result in a range of hardships that extend from a inconvenience, to lost business, to life-threatening situations.

#Referring now to the drawings, illustrative examples are shown in detail. Although the drawings represent the exemplary illustrations described herein, the drawings are not necessarily to scale and certain features may be exaggerated to better illustrate and explain an innovative aspect of an exemplary illustration. Further, the exemplary illustrations described herein are not intended to be exhaustive or otherwise limiting or restricting to the precise form and configuration shown in the drawings and disclosed in the following detailed description. Exemplary illustrations are described in detail by referring to the drawings as follows:

#FIG. 1 illustrates a premise that may include a building having a generator for backup.

#FIG. 2 illustrates an exemplary process flow for bringing a back-up generator online.

#The present disclosure is directed to a method and an apparatus for reducing cool down time and engine wear in a generator. As can be readily appreciated, the temperature of a generator is dependent on a number of factors that include but are not limited to the amount of load applied to the generator, when loads are applied, and a temperature of the environment in which the generator is placed. For instance, a large load (for instance, approaching the full load condition of the generator) applied for a relatively long time may cause the generator to heat up, but if the generator subsequently experiences a light load, the generator may have cooled significantly after the heavy load is discontinued and before it is desired to shut down the generator. The rate of cooling of the generator will also likely be dependent on the temperature of the environment in which the generator is positioned. Thus, the rate of cooling may vary in winter versus in summer, as an example. Thus, the disclosed embodiments account for the load applied and the amount of time that has transpired since the load was applied. In one example the environmental temperature where the generator is positioned is accounted for as well.

#FIG. 1 shows premise 100 that includes a building 102 having electrical power fed thereto from a primary electrical energy source or an electrical source 104, such as an electrical grid, via power lines 106. Electrical power is fed via lines 106 to building 102 and to a transfer switch 108. Transfer switch 108 is electrically coupled to a load center 110, which is electrically coupled to electrical loads 112, 114, and 116. Loads 112-116 may include but are not limited to air conditioning, computers, lighting, refrigeration, life-support systems, and power ports for re-charging electrical devices, as examples.

#A standby generator 118 is positioned on premise 100 and proximate building 102. Standby generators are often positioned outside of a building to provide an alternative or backup source of electrical power for facilities that rely on electrical power for preserving life, preserving perishable items, preventing accidents, preventing theft, and providing security, as examples. Often, a standby generator is designed or selected to provide backup power for a specific application, such as a residential, a commercial, or an industrial facility. For a residential application, it is typically desirable to provide backup power for freezers, air conditioning or heating, for lighting, or to recharge mobile devices and run a computer, as examples. Whereas in a commercial or industrial facility, backup power may be provided to keep the facility fully functional and with minimal downtime in the event or a power outage. In some instances it may be a legal requirement to include backup power (such as if a life-support system is being powered by the utility), as opposed to a “business requirement” (such as in a restaurant where it may be desired to keep operating and not inconvenience customers).