RLC Load Banks

An RLC load bank contains resistive, inductive and capacitive elements in one enclosure. The resistive section draws real power in kW, the inductive section draws lagging kVAR through iron-core reactors, and the capacitive section draws leading kVAR. Switching them in combination lets the operator load a generator or UPS at any chosen power factor instead of only at unity.

A resistive load bank loads the source at power factor 1.0. It proves kW output and exercises the engine, governor and cooling system, which covers most routine generator testing. An RLC load bank adds reactive load, so the alternator field, excitation system and AVR are tested as well and the set can be run at its full kVA nameplate rating. If your specification calls for testing at 0.8 power factor, you need an RLC unit.

Because that is how generators are rated. A set described as 500 kVA is 500 kVA at 0.8 lagging — 400 kW plus 300 kVAR. Loading it with 400 kW of pure resistance proves the engine but leaves the alternator running well under its design condition. Only reactive load brings the excitation system up to its rated point, which is where voltage regulation problems actually show up.

Leading power factor testing. UPS systems with capacitive input filters, inverter-fed and solar hybrid installations, and lightly loaded long cable runs all present a leading load, and generators behave differently under it — voltage can rise rather than sag. The capacitor section reproduces that condition so it can be checked before commissioning.

From 25 kVA units for UPS and small standby work up to 1000 kVA for large generator testing, with higher ratings achieved by paralleling units. The kW and kVAR split is set to the power factor range you need — a unit built for 0.8 lagging testing carries roughly three kVAR of reactive capacity for every four kW of resistive.

Yes. Where only reactive loading is needed — adding lagging kVAR to an existing resistive bank, for example — we build standalone inductive load banks and capacitive load banks. Many customers find the combined RLC unit better value once both are required, since one enclosure, one control panel and one cooling system serve all three sections.

We manufacture at our works in Peelamedu, Coimbatore, and supply RLC load banks regularly to Chennai and Bangalore — Bangalore is in fact our single busiest city for reactive load bank enquiries. We also supply Kochi, Kozhikode, Thiruvananthapuram, Hyderabad, Pune and the Delhi NCR region. Delivery, installation guidance and commissioning support are available in all of these locations.

Each capacitor bank carries bleed discharge resistors that bring the stored charge down to a safe level once the section is switched out, and the enclosure is fitted with a door interlock so the bank cannot be opened while energised. Warning labels and a discharge time are marked at the access point.

Send the kVA rating of the generator or UPS to be tested, the power factor range you need to cover, the test voltage and frequency, your preferred step resolution, and whether the unit will be indoor, outdoor or portable. Email sales@akshayamcontrols.co.in or call +91 89403 32552 and our engineers will size the unit and quote.