Automatic transfer switch

Abstract

An automatic transfer switch apparatus for use with a standalone generator, for supplying emergency power to a residence or small business. The automatic transfer switch apparatus is configured to sense a utility line failure, start up and stabilize the generator, and switch over the household circuits from the utility to the generator, and switch back when the utility recovers. The transfer switches incorporate motor driven switch interlock mechanisms in several embodiments as well as various operational features

1 . In an electrical system normally supplied with electrical power from a utility source, the electrical system further having an automatic starting auxiliary electrical power source having a predetermined maximum capacity, a method for setting up distribution of auxiliary electrical power amongst a plurality of loads, comprising the steps of:
 providing a switching apparatus disposed between the source of electrical power and at least two electrical loads wherein at least one of the electrical loads is a mandatory load and at least one of the electrical loads is a discretionary load, and configured to be able to bring the source of electrical power selectively into electrical contact with any combination of the at least two electrical loads;   providing a controller, connected to the utility source, the auxiliary electrical power source, and each of the at least two electrical loads;   providing the controller with memory for storing information regarding the electrical system,   starting the auxiliary electrical power source and monitoring the output of the auxiliary electrical power source;   setting each load on the electrical system to its maximum demand setting;   interrupting electrical contact between the auxiliary electrical power source and each of the loads;   connecting a first load on the electrical system, to the auxiliary electrical power source;   causing the controller to sense in the electrical system the first connected and storing that value as an assigned maximum value of that first connected load in memory;   disconnecting the first connected load from the auxiliary electrical power source, and successively connecting, sensing, storing and disconnecting each remaining load in the system to and from the auxiliary electrical power source, until all discretionary loads in the system have been connected, and their maximum load values sensed.   
     
     
         2 . The method according to  claim 1 , further comprising the steps of:
 assigning a disqualification value to any load sensed by the controller that exceeds a predetermined value of the capacity of the auxiliary electrical power source.   
     
     
         3 . A system for distribution of electrical power amongst a plurality of loads comprising:
 a source of electrical power, having a predetermined maximum capacity;   at least two electrical loads, each electrical load having been assigned a predetermined priority value relative to the provision of electrical power from the source of electrical power;   a switching device disposed between the source of electrical power and the at least two electrical loads, and configured to be able to bring the source of electrical power selectively into electrical contact with any combination of the at least two electrical loads;   a controller, connected to the source of electrical power and each of the at least two electrical loads;   the controller having memory therein containing as a stored value the predetermined maximum capacity of the source of electrical power;   the controller having memory therein containing as stored values the predetermined priority values of the at least two electrical loads;   the controller having memory therein containing as stored values the respective maximum load values of each of the at least two electrical loads, when each such electrical load is active;   the controller being configured to cause the switching device to bring into electrical contact with the source of electrical power each successive electrical load active and calling for electrical power, in order of descending priority so long as the addition of each successive electrical load results in a total load less than a predetermined percentage of the predetermined maximum capacity of the source of electrical power, such that if the addition of a prospective successive lower priority load would cause the total load to equal or exceed the predetermined percentage, the prospective successive lower priority load would not be brought into communication, if at all, with the source of electrical power, until the total of the total of the loads already in contact with the source of electrical power and the prospective successive lower priority load is less than the predetermined percentage; and   the controller further being configured, in the event that the total of the loads in contact with the source of electrical power exceeds the predetermined percentage for a continuous predetermined period of time, to successively disconnect the loads from the source of electrical power, beginning with the lowest priority load and continuing in ascending order, until the resulting total load is less than the predetermined percentage, and then reconnect, in descending order of priority, the next available load which results in a total load less than the predetermined percentage.