250 kVA GENERATOR

250 kVA is the prime rating on the nameplate, not a rounded-up figure — the frame maps exactly onto the requirement. 1500 rpm at 50 Hz, 1800 rpm at 60 Hz, three-phase four-wire, 0.8 power factor.

I = kVA × 1000 ÷ (√3 × V). Breaker sizing at 125% of the 400 V figure gives 451 A. Cable at 361 A needs roughly 2 × 120 mm² copper per phase for a run under 50 m. A single-phase 250 kVA set would need a bespoke alternator — balance the load across three phases instead.

At 1600 kg the open set lifts with a forklift; the canopied version needs a crane or a heavy forklift. Allow 1 m clearance at the alternator end for cooling air and confirm canopy door swing on both long sides before siting. Cast a level concrete plinth rated for 1.5× the wet weight.

Based on ≤192 g/kWh at 835 g/L diesel density — about 0.184 L per kVA per hour at rated load. Consumption tracks load almost linearly in this class, so a set held at 50% for 12 hours a day burns roughly half the full-load figure for twice as long: the fuel bill per kWh barely changes, but the engine runs cleaner.

Buyers ask for the tank capacity as often as they ask for the amps, and the two numbers are not independent: runtime is tank volume divided by consumption at the load you actually run. The baseframe tank is built to the order, so the right way to specify it is to start from the runtime you need.

Tank volume is specified per order — the figures above are the standard options, not a fixed rating. A 250 kVA set at 50% load is the most common operating point for a hotel or office, and it stretches runtime almost exactly twice versus full load. If the site needs 12 hours unattended, specify 400 L rather than 300 L and confirm the tank is double-walled with a bund — single-wall baseframe tanks are not acceptable in most jurisdictions for a set above 200 kVA.

Coupled to a Faraday FD3G-4 or Stamford HCI444 alternator, with a Deep Sea DSE7320 MKII controller as standard and DSE8610 for parallel operation. At 250 kVA the engine choice moves both price and serviceability — Cummins and Perkins have the widest parts network in Africa and the Middle East; Weichai and SDEC are the cost-competitive options with strong regional support; Volvo suits projects with emission or brand requirements. Note the Yuchai standby output: confirm the derate before specifying it for a continuous load.

Open-skid JJP-M200GF sets run US$14,000–20,000 FOB China. Engine brand moves that band more than anything else — Cummins and Perkins sit at the top, Weichai and SDEC at the bottom. A sound-attenuated canopy adds 8–12% and about 200 kg. Budget separately for a 500 A breaker, an ATS if the site needs automatic transfer, a synchronising panel if two sets run in parallel, and freight. Local market prices in India, Pakistan, Nigeria and South Africa usually run 40–80% above FOB once duty, inland freight and dealer margin are added — compare like for like before quoting a landed figure.