Load Bank

Load banks come in three electrical types: resistive (heat-only, simulates real power), inductive (lagging power factor, simulates motor / transformer load) and capacitive (leading power factor, simulates UPS and lighting circuit behaviour). The most common is the resistive load bank, built from stainless-steel wirewound or cast-iron grid resistors in stepped or continuously variable load steps. A 1 MW diesel generator commissioning test will typically use a 1.25 MW resistive bank at 0.8 power factor to fully exercise the alternator without exporting energy back to the grid.

Key load-bank design parameters are total power capacity (10 kW portable up to 5 MW trailer-mounted), voltage rating (low-voltage AC 230/400/480, medium-voltage 4160/6900/11000, DC 48/400/1500), load resolution (smallest selectable step, usually 1 – 5 % of full scale), cooling (natural convection for < 100 kW, forced air or water above), and instrumentation (true-RMS metering, harmonic analysis, IR thermography). Cabling and connectors are rated for sustained full-load current.

Load banks verify generator nameplate output, batteries' actual capacity vs spec, UPS run-time, EV charger output curves and data-centre redundancy schemes (“N+1 test”). Cabinet integration uses stainless-steel grid resistors mounted on insulating ceramic isolators with smart controllers running pre-programmed test profiles. Compliance: BS 6133, NFPA 110 for emergency-power testing.