Ground-fault circuit interrupter

Claim 2

A ground-fault circuit interrupter for connection between incoming hot, cold, and ground lines and outgoing hot, cold, and ground lines, said interrupter comprising: a test switch having a pair of test contacts and a pole normally lying against one of said test contacts, said one test contact being connected to said outgoing ground line; a resistor between the other of said test contacts of said test switch and one of said hot lines; a detector relay having a detector coil connected between said outgoing cold line and said pole and a pair of detector contacts actuatable on detection of a voltage differential between said outgoing cold and ground lines, whereby displacement of said pole against the other of said test contacts feeds current through said resistor to said detector coil; a main switch connected in series between said incoming hot line and said outgoing hot line; and control means connected between said detector contacts of said detector relay and said main switch for opening said main switch on actuation of said detector contacts on detection of said voltage differential and on energization of said detector coil by a current through said resistor.

Claim 3

The interrupter defined in claim 1 wherein said control means includes a circuit relay coil and said main switch is operated thereby, said circuit relay coil being connected to said contacts.

Claim 4

The interrupter defined in claim 2, further comprising means for maintaining said main switch open even after disappearance of said voltage differential.

Claim 5

The interrupter defined in claim 3 wherein said means for maintaining includes a latching relay having a latching coil connected to said detector contacts and having latching contacts connected to said circuit relay coil and said latching coil.

Claim 6

The interrupter defined in claim 4, further comprising a pair of alternately energizable indicators connected to said latching contacts and each energized in a respective position of said latching contacts.

Claim 7

The interrupter defined in claim 5, further comprising a reset switch operable to open-circuit said latching relay coil.

Claim 8

The interrupter defined in claim 5 wherein said indicators are lamps.

Claim 9

The interrupter defined in claim 5, further comprising a printed-circuit board carrying said relays, said switches, and said means.

Claim 10

A ground-fault circuit interrupter for connection between incoming hot, cold, and ground lines and outgoing hot, cold, and ground lines, said interrupter comprising: a detector relay having a coil connected between said outgoing cold and ground lines and a pair of contacts actuatable on detection of a voltage differential between said outgoing cold and ground lines; a switch connected in series between said incoming hot line and said outgoing hot line; and control means connected between said contacts of said detector relay and said switch for opening said switch on actuation of said contacts from detection of said voltage differential, said control means including a circuit relay coil having a pair of sides one of which is connected to both of said cold lines and juxtaposed with said switch for closing same when energized, and a latching relay having a latching coil with one side connectable through said contacts to said incoming hot line, said latching relay having a pole connected to said incoming hot line, a front contact against which said pole normally lies connected to the other side of said circuit relay coil, and a back contact connected to the other side of said latching relay coil.

Claim 11

A ground-fault circuit interrupter for connection between incoming hot, cold, and ground lines and outgoing hot, cold, and ground lines, said interrupter comprising: a detector relay having a coil connected between said outgoing cold and ground lines and a pair of contacts actuatable on detection of a voltage differential between said outgoing cold and ground lines; a switch connected in series between said incoming hot line and said outgoing hot line; and control means connected between said contacts of said detector relay and said switch for opening said switch on actuation of said contacts from detection of said voltage differential, said control means including a circuit relay coil having a pair of sides one of which is connected to both of said cold lines and juxtaposed with said switch for closing same when energized, and a latching relay having a latching coil with one side connectable through said contacts to said incoming hot line, said latching relay having a pole connected to said incoming hot line, a front contact against which said pole normally lies connected to the other side of said circuit relay coil, and a back contact connected to the other side of said latching relay coil.