The submersible cable is the single most safety-critical component in a borewell installation — it carries mains voltage through a column of water under pressure at depths where repair or replacement means pulling the entire pump assembly. Compromising on cable quality is a false economy that costs far more in motor burnouts and replacement costs.
Why Copper Conductor Grade Matters
Finolex and Polycab use 99.97% electrolytic grade bare copper — the highest purity commercially available. Cheaper cables use lower-purity copper with higher resistivity, causing greater voltage drop at depth and premature overheating of the motor at the end of a 150m cable run.
Cable Sizing by Installation Depth
Voltage drop in the submersible cable is a critical design parameter. For a 15 HP (11 kW) motor drawing 22A at 415V three-phase:
- At 100m depth: 4mm² copper cable → acceptable voltage drop
- At 150m depth: 6mm² copper cable required
- At 200m depth: 10mm² copper cable required
We calculate the correct cable cross-section for your exact installation during specification.