The "Static Grounding Monitoring System" functions as a part of an Overfill Protection & Earthing System. These provide a visual green light indicating a confirmed grounding condition of road tanker vehicles during the transfer of flammable and combustible materials. A red light indicates the absence of dependable grounding. An interlock circuit inside the control panel will prevent pumps and equipment from starting until a satisfactory ground is established. The interlock circuit will also shut off pumps and equipment if the ground is lost during the pumping operation.

The ATEX approved "Static Grounding Reels" have a self­retracting cable drum and an instant locking mechanism to prevent the cable from becoming tangled.