Cortem GRDE-4200 Ex Electronic Earthing System for Loading Bays

Electronic static earthing control for tanker and rail loading in Ex areas

The Cortem GRDE-4200 is an electronic earthing system that prevents static-electricity ignition when trucks or trains load and unload liquids and dry materials. During the whole transfer it checks that the equipotential bond is maintained through an earthing clamp. A protection circuit measures the connection resistance and compares it with the set parameter. If the value is inside the preset range the circuit between the two equipotential systems is closed; otherwise the operating consent to the loading pump is removed and the loading valve is closed.

The unit combines a Cortem Ex eb / tb enclosure, the certified grounding control logic LCZ-4200 and Ex eb / tb selectors and LED indicators. It can be supplied with one or two earthing clamps for connection to tank trucks or other metal parts. The cover of the datasheet states SIL certified level 2, with LED indicators, a control lever and an 8 m connection cable.

Technical specifications of the GRDE-4200

Selection: codes, voltages and weights

The code identifies the number of clamps, the enclosure material and the supply voltage. The aluminium versions weigh 3.25 kg with one clamp and 6.45 kg with two; the polyester versions weigh 2.80 kg and 5.65 kg.

Spare parts listed by Cortem include the LCZ-4200 monitoring logic (with /12, /24 and /110 variants), the PZCC-4209 earthing plier, the 20CE063 yellow cable (8 m), red and green multi-LED indicators for 12 V and the M-0604/2R special switch.

Where the system is used and what to confirm

Typical locations are tanker loading bays, jetties for oil, methane or gas tankers and silos transferring liquid or solid products. Poorly conductive solvents in plastic pipes, high flow rates and air bubbles increase charging, and an earth connection alone does not prevent sparks. The datasheet shows the system with an earthing clamp, ground bar type BTM and earth electrode type TZ.

Before ordering, confirm the supply voltage, one or two clamps, the enclosure material for the corrosion level of the site, the signal wiring to the pump starter and the loading valve, and the required certificate (ATEX, IECEx or UKEX).

Documents and quotation

The attached document is the Cortem GRDE-4200 datasheet (catalogue pages D.1-D.8, edition 2026) with certification data, selection tables and spare parts.

For a quotation, send the model code, voltage, zone and gas or dust group, cable entry details and quantity. See Automation Accessories for related hazardous-area equipment. Related hazardous-area equipment: Cortem EJBX stainless steel junction boxes.