UPS maintenance bypass systems using mode signaling

A system comprising:

• a UPS comprising converter circuitry, a static bypass switch configured to bypass the converter circuitry in a bypassed state of the UPS, and a control circuit configured to control the bypass switch;
• a power input configured to be coupled to a power source;
• a power output configured to be coupled to a load;
• a maintenance bypass (MBP) output configured to provide power to the UPS;
• a MBP input configured to receive power from the UPS;
• a first manual switch having first, second and third positions, the first position coupling the power input to the MBP output and coupling the power output to the MBP input, the second position coupling the power input to the power output and the MBP output and decoupling the MBP input from the power output, the third position coupling the power input to the power output, decoupling the MBP output from the power input and decoupling the MBP input from the power output, the first switch further comprising a first contact set configured to indicate a transition between the first and second positions;
• and
• a second manual switch interlocked with the first switch such that transitions of the first switch between the first position and the second position are enabled by actuation of the second switch and comprising a second contact set configured to indicate actuation of the second switch, wherein the first switch is configured to transition between the second position and the third position without actuation of the second switch,
• wherein the control circuit is coupled to the second contact set and configured to cause the UPS to transition to the bypassed state responsive to actuation of the second switch.