Quick answer
A 60 kVA generator delivers about 48 kW of three-phase 400 V power (at the standard 0.8 power factor). That is enough for the essential services of a small office block, a school or care home, a farm's milking parlour and cooling, a light-industrial unit with a few machines, or a construction site's cabins and tools. The conditions are that large motors are started one at a time and you keep roughly 20% headroom. It is not enough for a whole building with several chillers, lifts and a full commercial kitchen all running together.
This guide explains what a 60 kVA generator can realistically run, using typical loads for offices, schools, farms, workshops and building sites. Global Generators supplies new diesel generators from 10 to 3000 kVA, so the examples reflect the kind of load lists we are asked to check, not brochure maths.
What does 60 kVA actually mean?
kVA measures apparent power. Most equipment is labelled in watts, kW or amps, which relate to real power. Multiply kVA by the power factor to convert. Generator sets are normally rated at 0.8, so 60 kVA × 0.8 = 48 kW. Always plan around kW, not kVA.
| 60 kVA diesel generator | Typical figure | |--------------------------------------|----------------------------------------------------| | Apparent power | 60 kVA | | Real power at 0.8 power factor | About 48 kW | | Standby rating (emergency use only) | Often around 10% higher, e.g. 66 kVA (about 53 kW) | | Full-load current, three phase 400 V | About 87 A per phase | | Typical supply | Three phase, 400 V, 50 Hz | | Diesel use at full load | Roughly 10.5 to 13 litres per hour |
Standby versus prime. A standby rating is for emergency backup only, for the limited hours a site spends without mains power. A prime rating is what the set can deliver for regular running with a varying load. If you expect to run the generator often, plan around the prime figure. The examples in this guide use the more cautious 48 kW.
> Expert tip: Check which rating a listing quotes. A generator sold as "60 kVA standby" has less capacity for regular use than one sold as "60 kVA prime", even though the headline number is identical.
Why starting loads decide what it can run
Motors, compressors, pumps, lifts and air conditioners draw three to seven times their running current for a second or two as they start. A diesel generator can absorb that surge, but only within limits. A rough rule is that a motor started direct-on-line should be no more than about a third of the generator's kW rating, which on a 48 kW set is around 15 kW. With a star-delta starter, soft starter or variable speed drive, larger motors become possible. Alternators differ, so confirm the figure with the supplier for the exact set.
What can a 60 kVA generator run in an office or commercial building?
Offices combine lots of small loads with a few large ones, mainly air conditioning and lifts. Typical running loads look like this:
| Equipment | Typical running load | Notes | |------------------------------------------------|--------------------------|------------------------| | Air conditioning / VRF outdoor units | 10 to 25 kW | High start-up surge | | LED lighting (small block) | 3 to 5 kW | Steady load | | Comms room, servers and UPS | 3 to 6 kW | Critical, constant | | Passenger lift (7.5 to 11 kW motor) | 5 to 10 kW | Large surge on start | | Small power (sockets, PCs, printers) | 5 to 8 kW | Varies through the day | | Fire alarm, emergency lighting, access control | Under 1 kW | Always include these |
A worked example. A small office block with 18 kW of air conditioning, 4 kW of lighting, a 5 kW comms room, a lift averaging 8 kW and 6 kW of small power totals about 41 kW. That is roughly 85% of the 48 kW prime rating. It is workable, but there is not much headroom. Shedding non-essential sockets or splitting air conditioning into priority zones would bring the load down to a safer level.
What can a 60 kVA generator run in a school or care home?
Schools and care homes need a generator that keeps people safe and comfortable rather than one that runs everything. A typical priority list includes:
- Heating pumps and boiler controls (0.5 to 3 kW)
- Lighting and emergency lighting (3 to 5 kW)
- Nurse call, fire alarm and IT systems (1 to 3 kW)
- A passenger or bed lift (5 to 10 kW, with a large starting surge)
- Part of the kitchen, such as refrigeration and one oven (5 to 12 kW)
A full commercial kitchen can use 15 to 25 kW on its own, so a 60 kVA set normally runs part of the kitchen rather than all of it. Add the priority loads up and a typical care home comes to around 30 to 35 kW, which suits this size well.
What can a 60 kVA generator run on a farm?
Farm loads are dominated by motors and refrigeration, so starting order matters more than the total. Typical running loads include:
| Equipment | Typical running load | Notes | |-------------------------------|--------------------------|---------------------------| | Milking vacuum pump | 4 to 7.5 kW | Start before other motors | | Milk cooling compressor | 3 to 7.5 kW | Priority load | | Electric water heater | 3 to 6 kW | Steady load | | Feed auger or conveyor | 1.5 to 4 kW | Short surge | | Grain dryer fan | 7.5 to 15 kW | Large starting load | | Ventilation fans and lighting | 2 to 5 kW | Light load |
A worked example. A dairy farm running a 5.5 kW vacuum pump, a 5.5 kW milk cooler, a 6 kW water heater, a 2.2 kW wash pump and 1.5 kW of lighting totals about 21 kW. That is under half the generator's capacity, so even adding an 11 kW grain dryer fan (about 32 kW) is fine if you start the fan on its own.
What can a 60 kVA generator run in a workshop or light-industrial unit?
This is where a three-phase 60 kVA set earns its keep, because most fixed machinery is three phase. Typical loads include:
| Equipment | Typical running load | Notes | |---------------------------------|--------------------------|----------------------------------| | Air compressor (11 kW / 15 hp) | 11 kW | Needs soft start or star-delta | | CNC machine or machining centre | 7 to 15 kW | Check the machine's input rating | | Heavy MIG welder | 8 to 15 kVA | At full output | | Dust and fume extraction | 4 to 7.5 kW | Start early | | Workshop lighting | 2 to 3 kW | Negligible |
A worked example. A 7.5 kW compressor, a 4 kW extractor, 2 kW of lighting and two 4 kW machines total about 21.5 kW running, which is comfortable. The compressor is the risk, because started direct-on-line it can cause a voltage dip. A soft starter on the compressor solves it.
> Expert tip: On a three-phase generator, single-phase loads draw from one phase only. A 60 kVA set has roughly 20 kVA per phase, so spread single-phase sockets, lighting and small machines across all three phases. Overloading one phase can trip the generator long before the total reaches its rating.
What can a 60 kVA generator run on a construction site or event?
For temporary supplies, a 60 kVA set typically covers:
- Several site cabins, each using 3 to 5 kW with heating or air conditioning
- Tower lights and general lighting (1 to 2 kW each)
- 110 V power tools through a transformer, which adds a little to the load
- A concrete mixer, a pump or a welder, one at a time
Temporary installations need careful earthing. The HSE's guidance on the electrical safety of portable and mobile generators explains the principles that apply.
What a 60 kVA generator will not run comfortably
- A whole building with several chillers, lifts and a full kitchen all at once.
- A 30 kW or larger motor started direct-on-line.
- Multiple large motors starting at the same moment.
- Cold storage with more than one or two large condensing units alongside other loads.
- Continuous running at close to 100% load with no headroom.
How to size a 60 kVA generator for your site
- List everything that must keep running. Be strict and include only essentials.
- Find each running load on the equipment's rating plate, in kW or amps.
- Find the largest starting load and check its starting method against the generator's motor-starting capability.
- Add 20 to 25% headroom for surges and future equipment.
- Aim for a typical load of 40 to 80%. Diesel engines run lightly loaded for long periods can suffer from wet stacking, where unburnt fuel builds up in the exhaust.
> Not sure your load list adds up? Send us your equipment list and we will check it against a set from stock. Speak to our team through the contact page or call +44 1302 700200.
Fuel use and running costs
A diesel generator burns fuel roughly in proportion to its load. Typical figures for a 60 kVA set are below, but each model differs, so check the datasheet:
| Load | Power output | Approx. diesel use | |----------|------------------|----------------------------| | 25% | About 12 kW | 3.5 to 4.5 litres per hour | | 50% | About 24 kW | 5.5 to 7 litres per hour | | 75% | About 36 kW | 8 to 9.5 litres per hour | | 100% | About 48 kW | 10.5 to 13 litres per hour |
As an example, a 200-litre tank at half load would run for around 30 hours. To estimate running cost, multiply litres per hour by your current diesel price. Our guide to fuel saving methods for generators explains how load management and tank sizing affect your costs.
Silent or open, standby or prime?
Silent (canopied) sets are enclosed to cut noise and protect the engine from weather. They suit sites near neighbours, offices and care homes. If staff will work close to the generator, the HSE's noise at work guidance sets out the employer's duties as daily exposure rises. Compare enclosures in our range of silent generators.
Open sets cost less and are easier to access for servicing, but they are loud and need a plant room or a weatherproof housing.
Standby installations normally use an automatic mains failure panel and a changeover switch, so the building switches to generator power within seconds of an outage. If the generator will also run during normal operation, ask for a prime-rated set.
Should you choose 50, 60 or 80 kVA?
If your realistic load is under about 35 kW, a 50 kVA generator may be enough and costs less to buy and run. If it is above about 40 kW or you have large motors to start, step up to an 80 kVA generator. A 60 kVA set suits loads of roughly 30 to 40 kW with sensible headroom. It is almost always cheaper to size correctly at the start than to replace an overworked set later.
Siting, safety and regulations
- Ventilation and exhaust. Diesel exhaust contains carbon monoxide. Never run a generator indoors or in an enclosed space, and keep exhausts away from doors, windows and air intakes.
- Earthing. Correct earthing protects people and equipment. Our generator earthing requirements guide explains what applies on UK sites.
- Fuel storage. In England, storing more than 200 litres of oil at business premises usually requires secondary containment (a bund) under the Control of Pollution (Oil Storage) (England) Regulations 2001. Check with the Environment Agency if your tank is larger.
- Permits. Environmental permit rules apply to medium combustion plants and specified generators, which are much larger than a 60 kVA set. You can confirm the thresholds in the GOV.UK guidance on medium combustion plants and specified generators.
- Servicing. Regular servicing and a monthly on-load test keep a standby set reliable.
Frequently asked questions
How many kW is a 60 kVA generator?
At the standard power factor of 0.8, a 60 kVA generator produces about 48 kW. Some sets quote a slightly different figure, so check the rating plate.
How much diesel does a 60 kVA generator use per hour?
Roughly 3.5 to 4.5 litres per hour at 25% load, rising to about 10.5 to 13 litres per hour at full load. The exact figure depends on the engine and model.
How many homes can a 60 kVA generator power?
Essential loads for a typical UK home are around 4 to 5 kW, so a 60 kVA generator could in theory supply the essentials of several homes. In practice, supplying separate properties raises safety and legal questions, so use a generator this size for a single site rather than a street.
Can a 60 kVA generator run a lift, air conditioning or a compressor?
Yes, within limits. A lift or air conditioning system can be run alongside other loads if you account for the starting surge. For compressors and other large motors, keep direct-on-line motors to around 15 kW or use a soft starter or star-delta starter.
Is a 60 kVA generator single phase or three phase?
Most 60 kVA generators are three phase, 400 V. They can also supply single-phase 230 V loads, although each single-phase circuit is limited to roughly one third of the total, about 20 kVA per phase.
How long can a 60 kVA diesel generator run continuously?
A well-maintained diesel generator can run for many hours or days if it is refuelled and kept within its rated load. For regular running rather than emergency use, check that the set is rated for prime power and follow the manufacturer's service intervals.
Conclusion
A 60 kVA generator is a capable size for offices, schools, farms, workshops and building sites. It can carry roughly 48 kW of real load, provided you account for your biggest starting loads and leave a sensible margin. Work out your essential load, check your motor starting methods and choose the right enclosure and rating before you buy.
> Talk to a real person: Global Generators is an authorised Cummins reseller and an authorised Grupel and Pramac dealer, with new diesel generators in stock for UK delivery and export. Browse our full 60 kVA generator range, or contact our team on +44 1302 700200 or at enquiries@global-generators.com and we will help you match a set to your load.