Three-source automatic redundant bypass-isolation switches and related power systems and methods

A system for powering a load, comprising:

• a housing;
• an automatic transfer switch withdrawably held in or by the housing configured to selectively (i) connect the load to only a first power source (ii) connect the load to only a second power source, and (iii) disconnect the load from the first and second power sources;
• a bypass switch withdrawably held in or by the housing configured to selectively (i) connect the load to only the first power source, (ii) connect the load to only a third power source, and (iii) disconnect the load from the first and third power sources;
• and
• a control circuit in communication with the automatic transfer switch and the bypass switch to automatically direct the bypass switch and the automatic transfer switch to carry out the selective connections with power transitions to the load from the first, second and third power sources,
• wherein the automatic transfer switch cannot connect to the third power source and the bypass switch cannot connect to the second power source, and wherein, after a respective power transition, only one of the first power source, the second power source or the third power source powers the load.

An assembly comprising:

• a housing;
• an automated transfer switch (ATS) held in or by the housing and configured to connect a load to a first power source or a second power source;
• a bypass switch held in or by the housing and configured to connect the load to a third power source;
• and
• a control circuit in communication with the ATS and the bypass switch, wherein the control circuit is configured to selectively connect a single one of the first, second, or third power sources to the load such that, after a power transition, only the connected single one of the first, second or third power sources powers the load using one of the ATS or bypass switch, and wherein the control circuit is further configured to disconnect the load from any of the first, second or third power sources.

A method of controlling a power system, comprising:

• providing a switch assembly comprising an automated transfer switch and a bypass switch in separate compartments of a single housing enclosure;
• electrically coupling a first power source, a second power source and a third power source to the switch assembly;
• connecting a load to the switch assembly to selectively electrically engage each of the automatic transfer switch and the bypass switch;
• and
• electronically controlling operation of the switch assembly to automatically engage either the automatic transfer switch or the bypass switch and an appropriate single power source selected from the first power source, the second power source or the third power source at any one time after a respective power transition based on defined logic input conditions and power transition routines, wherein the switch assembly connects only a single one of the first power source, the second power source or the third power source to power the load before or after transitioning power to the load from another single one of the first, second or third power source.