Electrical line-fault detector and circuit breaker device

An electrical circuit breaker apparatus for disconnecting power supplied to a load device by a power source by way of internal wiring conductors of a building, comprising:

• voltage detection means for obtaining a first voltage representative of the voltage at the power source when the load device is turned "off" and for obtaining a second voltage representative of the voltage drop across the load obtained when the load device is "on";
• subtractor means for obtaining a voltage difference between said first and second voltages;
• multiplier means for multiplying said voltage difference by the current flowing through the load device to obtain a power loss value indicative of the power loss due to a Series resistance present in internal wiring connecting the load device in series with the power source;
• and,
• disconnect means for disconnecting said load device from said power source if said power loss value is above a predetermined level.

An electrical circuit breaker apparatus located near a load device for disconnecting power supplied to a load device by a power source due to an electric fault condition within the internal wiring connecting the power source in series with the load device in a building, comprising;

• first voltage detection means for obtaining a reference voltage by measuring the voltage drop across the load device when the load device is turned "off";
• second voltage detection means for obtaining a second voltage value representative of the voltage drop across the load device when the load device is turned "on";
• comparator means for obtaining a voltage difference representative of the voltage difference between said first and second voltages;
• and
• disconnect means for disconnecting said load device from said power source if said voltage difference is above a predetermined level.