초록 ▼

A system for transferring a load from a first to a second AC power source, including a monitor for sensing both power sources and producing an output signal when the differences in voltage, frequency, and phase between the two sources are within prescribed limits. Contacts close, in response to the

A system for transferring a load from a first to a second AC power source, including a monitor for sensing both power sources and producing an output signal when the differences in voltage, frequency, and phase between the two sources are within prescribed limits. Contacts close, in response to the monitor output signal, to connect the second power source to both the first power source and the load. Other contacts open, to disconnect the first power source from the second power source and load, but only after the second power source has been connected to the first power source and the load. The contact arrangement may include an automatic transfer switch and separate contacts in parallel with one or both sets of transfer switch contacts, or it may involve two independently operable contactors, or it may involve a four position switch.

대표청구항 ▼

A system for transferring a load from a first AC power source to a second AC power source without interrupting power supply to the load, comprising: (a) a monitor for sensing both power sources and producing an output signal when the differences between certain characteristics of the two sources are

A system for transferring a load from a first AC power source to a second AC power source without interrupting power supply to the load, comprising: (a) a monitor for sensing both power sources and producing an output signal when the differences between certain characteristics of the two sources are within prescribed limits, (b) contact means which when closed and open connect and disconnect, respectively, the first AC power source to the load, (c) contact means which when closed and open connect and disconnect, respectively, the second AC power source to the load, one of said contact means being open and the other closed during steady state operation of the system, (d) additional contact means connected in parallel with one of said contact means (b) and (c), the additional contact means, when closed, connecting one of the power sources to the load, (e) means responsive to an output signal from the monitor for closing the additional contact means, and (f) means responsive to closing of the previously open contact means (b) and (c) and to opening of the previously closed contact means (b) and (c) for opening the additional contact means.