If you're planning to install a diesel generator for your home, villa, or commercial facility in the UAE, one of the most important steps is calculating the right generator load size. Choose a generator that’s too small, and you risk overloads and shutdowns. Go too big, and you’ll end up paying more than you need to- not just for the generator, but for fuel, maintenance, and installation.
In this post, we’ll break down exactly how to calculate the ideal diesel generator load, especially for businesses and industries operating in Dubai, Abu Dhabi, and across the GCC.
Why Load Calculation Matters
A proper load calculation ensures that your generator can handle all the electrical equipment you plan to run- from lights and HVAC to pumps, elevators, and industrial machines.
Getting it right helps:
· Avoid system failures or short circuits
· Extend the life of your generator
· Ensure efficient fuel consumption
· Comply with DEWA/ADDC regulations for backup systems
Step-by-Step: How to Calculate Diesel Generator Load
Here’s a simplified approach to generator sizing for most projects:
1. List All Electrical Devices
Start by listing all the appliances, machines, and systems that will run on generator power. Group them into:
· Essential loads (what must stay on during a power cut)
· Non-essential loads (things you can switch off)
Tip: For villas or offices, this usually includes lights, ACs, fridges, water pumps, servers, and security systems.
2. Note the Wattage or kVA
Check the power ratings of each device. These may be listed in:
· Watts (W) or kilowatts (kW) – real power
· kVA – apparent power (includes power factor)
1 kW = 1000 watts. Most diesel generator sizes are rated in kVA.
3. Account for Starting Loads
Some equipment- like AC units, elevators, or compressors- have surge or starting currents that are 2 to 3 times higher than their running power.
Example: A 1.5-ton split AC may need 1.5 kW running, but 3–4 kW to start.
4. Apply a Safety Margin
Once you’ve added up the running load and surge load, multiply the total by 1.25 (or 25%) to add a buffer.
Example:
|
Equipment |
Running Load (kW) |
|
Lights & Fans |
2 |
|
Air Conditioners |
6 |
|
Refrigeration Units |
2 |
|
Water Pump |
1 |
|
Server Rack |
1 |
|
Total |
12 kW |
· Add surge load: ~3 kW
· Apply margin: 12 + 3 = 15 × 1.25 = 18.75 kW
This means you should consider a 20 kVA diesel generator (approx. 16–18 kW) for reliable operation.
Choosing the Right Generator
Once you’ve calculated your load, it’s time to match it with the right generator model. Factors to consider:
· Brand and engine type (Perkins, Cummins, Baudouin, etc.)
· Prime vs standby rating
· Single-phase or three-phase
· Local service support in the UAE
If you're unsure, it’s best to consult a generator expert who can assess your site and recommend the right unit. Contact Master Power’s team for a free assessment or quote.
Common Mistakes to Avoid
· Ignoring surge loads: This is a leading cause of generator failure.
· Underestimating HVAC and motor loads: These often draw more power than expected.
· Skipping professional advice: Especially for larger buildings or mixed-use properties.
Final Thoughts
Getting your diesel generator load calculation right is not rocket science- but it’s not something you want to guess either. Whether you're powering a villa in Dubai or a construction site in Abu Dhabi, accurate load sizing means peace of mind, lower fuel costs, and better long-term performance.
Need help choosing the right generator for your needs? Talk to Master Power- we’ll help you calculate, select, and install the perfect unit for your location and load profile.