How do you check electrical grounding from the building ground to a conveyor?

Question

Looking for a way to insure good grounding throughout a conveyor that is 2000' long. The main beams of the plant are bolted together then bolted to the deck in which case is wielded to the base of the conveyor. We use a megger to check conveyor to rack by hooking one end to the conveyor and the other to the rack, then cranking handle and reading current that is passing through them.

Answer 1

Check for ohm resistance between the furthermost point of the conveyor to a known good ground. Some resistance is inevitable and depends on the length of the total circuit.

You could also check the voltage drop using DC current (from a battery). Use the conveyor and even the building ground as the negative, and measure the voltage to the positive terminal to determine the voltage drop. Again some voltage drop is inevitable and depends on the circuit length.

Answer 2

Generally in a mining situation, a gound conductor is installed along the conveyor and each leg is grounded to the conductor and to earth. The grounding conductor can either be buried or placed in a cable tray/ladder.