Generators
500 kVA generator
A 500 kVA generator delivers 400 kWe at a power factor of 0.8 and 722 A at 400 V. It sits close to the 1 MW thermal input at which the EU combustion plant rules begin, so the engine data sheet matters as much as the rating.
- Real power
- 400 kWeat power factor 0.8
- Full load current at 400 V
- 722 Acalculated
- Transfer switch
- 800 Athe next common rating above the 400 V current; your designer confirms it
- Rated thermal input
- about 1 MWmodelled at 38 to 42 % efficiency; the engine data sheet states it
What 500 kVA carries
A 400 kW load at a power factor of 0.8 needs exactly 500 kVA, so a set of this rating is full on its first day. A better power factor lowers the kVA drawn but not the ceiling: the engine caps real power at about 400 kWe, and a 450 kW load needs a larger set whatever its power factor.
For a UPS load the set carries the UPS input, battery recharge included, not the IT load behind it. Ask the UPS maker for that input figure and put it in the request.
Ratings either side of 500 kVA
| Rating | Real power at power factor 0.8 | Full load current at 400 V | Full load current at 415 V | Next step |
|---|---|---|---|---|
| 400 kVA | 320 kWe | 577 A | 556 A | Request a quote |
| 500 kVA | 400 kWe | 722 A | 696 A | Request a quote |
| 630 kVA | 504 kWe | 909 A | 876 A | Request a quote |
kWe at power factor 0.8. A load that outgrows 400 kWe moves to the 630 kVA row; one that stays near 320 kWe fits the 400 kVA row.
Standby or prime at 500 kVA
The 500 kVA on an offer is a rating at a stated duty. The same engine and alternator carry less at prime power than at emergency standby, so an offer reading 500 kVA standby describes a smaller machine than one reading 500 kVA prime. Ask for both figures and compare offers at the duty you will actually run.
The 1 MW line
Directive (EU) 2015/2193 applies from 1 MW of rated thermal input. At 38 to 42 percent electrical efficiency a 500 kVA set burns fuel at about 0.95 to 1.05 MW, so it may fall on either side of that line. The engine's rated thermal input on the data sheet decides it, not the kVA.
Below 1 MW a set is not counted when several plants share a stack. At or above it, a stationary set needs a permit or registration before it runs, and a Member State may exempt sets running no more than 500 hours a year from the emission limits. A mobile set of this size falls under Regulation (EU) 2016/1628 instead, with an engine below the 560 kW at which category NRG starts.
In England and Wales the same line decides whether the set is medium combustion plant under the Environmental Permitting Regulations. At or above it, a new set needs its permit before it is commissioned, and the Environment Agency is clear that an emergency backup tested 50 hours a year or less still needs one.
What shapes the offer
After the duty, the enclosure shapes it: an open set in a plant room, a sound attenuated canopy outdoors, or a container with its own tank. The sound limit at a stated distance usually decides between them, so give that limit with the site plan.
What we need to quote a 500 kVA generator
- 500 kVA at the duty you will run: standby, prime or continuous
- The load in kW, its power factor and the largest single step
- Voltage and frequency: 400/230 V or 415/240 V, 50 Hz
- Fuel and the runtime at a stated load
- Plant room, canopy or container, and any sound limit
- Stationary or mobile, and the expected hours a year
Questions buyers ask
How many amps does a 500 kVA generator supply?
722 A per phase at 400 V and 696 A at 415 V, at full rating. The figure is S / (√3 × V).
How many kW is a 500 kVA generator?
400 kWe, the 500 kVA at the power factor of 0.8 that generating set ratings are stated at. The engine caps the real power there, so a load with a better power factor does not raise it.
Which transfer switch suits a 500 kVA generator?
One rated at or above the 722 A full load current at 400 V; 800 A is the next common rating. Poles, transition and the fault level at the board decide the rest.
Building or expanding a facility?
Send the whole equipment schedule as one project, each item with its own requirements.