Transfer switch position sensing using coil control contacts
AssigneeASCO Power Technologies, L.P.
InventorJohn Hayes
Life of this patent
Estimating the term…
Abstract
A method and apparatus for determining the position of the main contacts of an automatic transfer switch, without need for special position contacts, by monitoring for the presence of voltages at the normal source voltage contacts, the alternate source voltage contacts, the normal source coil control voltage contacts and the alternate source coil control voltage contacts of the automatic transfer switch, and providing an indication of switch position in response thereto.
Claims26
A method of determining the state of an automatic transfer switch having main contacts connectable to an electrical load, normal source contacts connected to a normal source of voltage, alternate source contacts connected to an alternate source of voltage, said main contacts being movable between a normal position at which said main contacts are connected to said normal source contacts and an alternate position at which said main contacts are connected to said alternate source contacts,
- electromechanical actuator means operatively connected to said main contacts for moving said main contacts between said normal position and said alternate position, normal coil control voltage contacts connected to said actuator means and connectable across the normal source of voltage for inducing said actuator means to move said main contacts to said alternate position, and alternate coil control voltage contacts connected to said actuator means and connectable across the alternate source of voltage for inducing said actuator means to move said main contacts to said normal position comprising;
- determining whether there is a voltage across the normal source contacts,
- determining whether there is a voltage across the alternate source contacts,
- determining whether there is a voltage across the normal coil control voltage contacts,
- determining whether there is a voltage across the alternate coil control voltage contacts, and
- producing a signal indicating the position of said main contacts as a function of the voltages across the normal source contacts, the alternate source contacts, the normal coil control voltage contacts, and the alternate coil control voltage contacts.
Apparatus for determining the state of an automatic transfer switch having main output contacts connectable to an electrical load, normal source contacts connected to a normal source of voltage, alternate source contacts connected to an alternate source of voltage, said main contacts being movable between a normal position at which said main contacts are connected to said normal source contacts and an alternate position at which said main contacts are connected to said alternate source contacts, electromechanical actuator means operatively connected to said main contacts for moving said main contacts between said normal position and said alternate position, normal coil control voltage contacts connected to said actuator means and connectable across the normal source of voltage for inducing said actuator means to move said main contacts to said alternate position, and alternate coil control voltage contacts connected to said actuator means and connectable across the alternate source of voltage for inducing said actuator means to move said main contacts to said normal position, said apparatus comprising;
- normal source voltage monitoring means for determining whether there is a voltage across the source contacts,
- alternate source voltage monitoring means for determining whether there is a voltage across the alternate source contacts,
- normal coil control voltage monitoring means for determining whether there is a voltage across the normal coil control voltage contacts,
- alternate coil control voltage monitoring means for determining whether there is a voltage across the alternate coil control voltage contacts, and
- processor means responsive to said normal source voltage monitoring means, alternate source voltage monitoring means, normal coil control voltage monitoring means, and alternate coil control voltage monitoring means, for producing a signal indicating the position of said main contacts as a function of the voltages across the normal source contacts, the alternate source contacts, the normal coil control voltage contacts, and the alternate coil control voltage contacts.
Dependencies are inferred from the claim text.