1) Define the loads
Start by listing the equipment you want to run during a power outage: lighting, air conditioning, pumps, refrigerators, elevators and motors. Add up their power in kilowatts.
2) Mind the starting current
Motors, pumps and air conditioners draw a higher current when starting than when running continuously (up to several times higher). So it is not enough to add up the continuous loads only.
3) kW versus kVA
Generator capacity is usually measured in kVA, with the approximate relation: kVA = kW ÷ power factor (usually 0.8). So a 40 kW load becomes about 50 kVA.
4) Safety margin
It is advisable to leave a safety margin above the calculated load, usually larger for prime duty than for standby duty.
5) Standby or prime?
Decide whether the generator will run only when the grid fails or as a permanent power source; this affects the choice.
6) Silent canopy or open frame
The canopy reduces noise and protects the generator from the weather, and is suitable for residential and outdoor sites.
7) Brand and technical support
Choose a brand whose spare parts and maintenance are available in your area, and ask about delivery time and after-sales support.
Choosing a diesel generator step by step
Choosing a diesel generator becomes easier when you follow a clear order. First list the loads, then add the starting current, convert kW to kVA, add a safety margin, decide on standby or prime duty and finish with the canopy and brand. Each step reduces the risk of buying a diesel generator that is too small, too large or hard to service.
The most common mistake is to add only the running loads and ignore starting current. Motors, pumps and air conditioners draw several times their running current when they start, and the generator must carry that peak without voltage collapse. A diesel generator should also run at a healthy load, usually between 50 and 80 percent, to avoid wet stacking.
Think about where the diesel generator will stand. A silent canopy protects the set from weather and reduces noise near homes and offices, while an open frame suits a plant room. Check ventilation, exhaust routing, fuel storage and access for maintenance before the set arrives.
Finally, choose a brand with parts and technical support in your area, and ask for a written quotation that states capacity, brand, canopy, delivery and warranty. Our engineers can review your list and recommend a diesel generator that fits your project.
AlRyada Generators (ARG) — we supply diesel generating sets from 10 to 3500 kVA with global engine brands, plus installation, commissioning, technical support and spare parts.
Generating sets
Contact us
- Building 4, Tuilib District, Elshrouk City, Cairo, Egypt
- +2 011 53267374
- +2 011 03388485
- sales@alryada-em.com