Earthing & Grounding Systems
Importers in Mymensingh

25×3 mm to 50×6 mm GI or copper strip covers most grid and bonding runs. Use 25×3 mm for equipment bonding and smaller grids, and 50×6 mm for main substation earthing grids and high-fault-current paths. Check the strip size against the fault current and clearance time using the adiabatic formula in IEC 60364-5-54 Annex A rather than picking a size out of habit.

The coupling, where two rod sections join, is the most vulnerable point in the whole installation. A carbon-steel coupling on a copper-bonded rod creates a bimetallic junction that corrodes far faster than the rod body itself, particularly in aggressive soil. Specify stainless steel or solid copper couplings every time, and treat a mild-steel coupling offered "to save cost" as a warning sign, not a bargain.

Find out who actually does the copper-bonding: an in-house electroplating line, or a subcontractor a few steps removed. Ask for a DFT test report and ISO 9001 certificate as samples. Then ask one pointed technical question, the target resistance at your soil resistivity, and notice whether the answer comes from someone who understands soil chemistry or gets bounced back unanswered. A real manufacturer controls the plating process end to end and backs every claim with paperwork.

IS 3043 clause 5.4 covers conductor sizing. For general industrial earthing grids, 25×3 mm GI strip is the working minimum. Substations, distribution transformers and data centre main earth bars step up to 50×6 mm GI strip or 50×3 mm tinned copper, sized to carry the maximum earth-fault current for the fault-clearing time set by the protective relay. The cross-section formula is from IEEE 80 (or IS 3043 Annex B), we size on request when you share the prospective fault current and relay setting.