Self-proving vehicle grounding system

A system for grounding a vehicle to the same ground voltage potential as a loading rack and disabling any loading operations from occurring if the ground is not properly established or if the vehicle is fully loaded, comprising:

• a ground controller unit electrically coupled to the ground of the loading rack, which comprises;
• (a) means for generating a first electrical signal,
• (b) means for detecting a second electrical signal, coupled to the means for generating;
• a grounding bolt unit electrically coupled to the vehicle, which comprises;
• (a) means for modifying the first electrical signal when electrically coupled to the controller unit so as to provide the second electrical signal at the input of the means for detecting.
• an overfill protection sensor circuit unit associated with the vehicle having an electrical ground for sensing when the vehicle is fully loaded and generating a FULL signal indicating the condition of being fully loaded;
• an overfill protection base unit associated with the loading rack for disabling the loading equipment when the FULL signal is generated;
• and
• means for electrically coupling the means for generating a first electrical signal to the means for modifying the first electrical signal and for coupling the FULL signal to the overfill protection base unit.

A self-proving grounding system for coupling the electrical ground of a loading rack to the electrical ground of a transport vehicle and preventing the loading of fluid from the loading rack to the vehicle except when their grounds are coupled together and the vehicle is not fully loaded, comprising:

• a ground controller unit adapted to be electrically grounded to the loading rack, comprising:
• (a) a first pair of terminals for coupling to an alternating current voltage source;
• (b) a transformer having first and second windings with the first winding coupled to said first pair of terminals for stepping the alternating current voltage to 30 volts AC at the second winding;
• (c) a first voltage divider coupled to the second winding of the transformer;
• (d) an operational amplifier having an inverting input coupled to the voltage divider;
• (e) a charge pumping circuit having an input coupled to the second winding of the transformer;
• (f) a charge and hold capacitor coupled to the charge pumping circuit so as to be charged by the charge pumping circuit to a second voltage which is less than the first voltage;
• (g) a second voltage divider having an input coupled to the charge and hold capacitor and an output coupled to a non-inverting input of the operational amplifier;
• (h) a transistor configured as a common emitter saturated switch having a base junction coupled to the output of the operational amplifier;
• (i) a relay having an input coupled to the collector junction of the transistor;
• (j) one or more dry contacts coupled to the output of the relay and enabled when the relay is energized;
• (k) first connector means coupled to the dry contacts for allowing connection of the dry contacts to external electrically powered equipment;
• (1) second connector means having first and second terminals, the first terminal coupled to the output of the charge pumping circuit and the second terminal coupled to the ground of the controller unit;
• a bolt unit adapted to be electrically grounded to the transport vehicle, comprising:
• (a) a modifier diode having an anode and a cathode;
• (b) third connector means having third and fourth terminals, the third terminal coupled to the cathode of the modifier diode and the fourth terminal coupled to the anode of the modifier diode and the ground of the transport vehicle;
• an overfill protection sensor circuit unit associated with the vehicle and having an electrical ground for sensing when the vehicle is fully loaded and generating a FULL signal indicating the condition of being fully loaded;
• an overfill protection base unit associated with the loading rack for disabling the loading equipment when the FULL signal is generated;
• and
• a cable for coupling the first and third terminals together and the second and fourth terminals together so as to couple the modifier diode to the charge pumping circuit so as to cause the charge pumping circuit to charge the capacitor to a third voltage which is greater than the first and second voltages, when the multi conductor cable is connected and further coupling the FULL signal of the overfill protection sensor circuit to the overfill protection base unit.