Electronic load control unit (ELCU) used as bus tie breaker in electrical power distribution systems

An electrical power distribution system comprising:

• a first source of electrical power connected to a first primary distribution panel (PDP);
• a second source of electrical power connected to a second PDP;
• electrical load;
• said first and second source of electrical power each having at least one power bus associated with them such that either of said first or second source of electrical power can feed both busses as appropriate;
• a first electronic load control unit (ELCU) having a first contactor connected to said first source of electrical power, said first contactor having open and closed modes;
• an auxiliary ELCU having a first contactor connected to said first source of electrical power, said first contactor having open and closed modes;
• a second ELCU having a second contactor connected to said second source of electrical power, said second contactor having open and closed modes;
• a conductor connected to said second contactor and to said electrical load;
• and
• said first or alternatively said auxiliary ELCU sensing a current in a cross-tie conductor from said first source and in response thereto, opening said first contactor and at least one of said first and second ELCUs closing said second contactor to permit electrical power to flow from said second source to said first PDP through said cross-tie conductor.

A circuit for protecting an electrical power distribution system comprising:

• a first power distribution panel (PDP) connected to a first source of electrical power;
• a second PDP connected to said first PDP by a conductor;
• a three phase electrical load connected to said first PDP;
• a first ELCU receiving signals corresponding to the flow of current through each of the three phases of said three phase electrical load;
• an auxiliary ELCU receiving signals corresponding to the flow of current through each of said three phases of said three phase electrical load;
• a second ELCU receiving signals corresponding to the flow of current through said second PDP;
• and
• at least one of said auxiliary, first and second ELCUs responding to the detection of a phase imbalance between said flow of current through said three phases by disconnecting said source of electrical power selectively such that power to said electric load is switched on or off depending on processing current information so that operation is not permitted along any path when a missing phase is detected.