Key Takeaways
- Accurate power assessment prevents under-sizing or overpaying for rental generators.
- Identify total wattage requirements for all critical and non-critical equipment.
- Consider load type, usage hours, and startup surges before choosing a model.
- Assos Power helps clients calculate precise generator size for any commercial or residential need.
- A proper power audit reduces rental costs, fuel usage, and downtime risk.
Why Power Assessment Is the First Step in Generator Hire
Renting a generator isn’t just about getting the biggest machine available — it’s about getting the right size for your specific load. A mismatch can lead to:
- Fuel waste and carbon buildup from oversizing
- Overloads and equipment damage from undersizing
- Higher rental costs and more frequent refuels
That’s why Assos Power emphasizes the importance of properly calculating your power demands before confirming any rental.
Step 1: List All Equipment That Requires Power
Start by identifying every device or system you plan to run off the generator.
Typical load categories include:
- Lighting (indoor, outdoor, or emergency)
- Appliances (fridges, freezers, kettles)
- Office equipment (computers, printers, routers)
- Power tools (drills, grinders, compressors)
- HVAC units (heaters, fans, aircons)
- Medical or event gear (sound systems, sterilizers)
Assos Power recommends separating essential loads from optional loads. This lets you scale capacity based on urgency and cost.
Step 2: Calculate Starting and Running Wattage
Every appliance has two energy ratings:
Running wattage – what it uses while operating.
Starting wattage – the surge required to power on.
Some machines, like air conditioners or compressors, use up to 3x more power during startup.
Example:
- A 1.5kW aircon may have a starting wattage of 4.5kW
- A drill might run on 800W but spike to 1600W on startup
Assos Power helps customers calculate both figures using wattage charts or appliance specs, ensuring no surprise overloads.
Step 3: Identify Load Type – Resistive vs. Inductive
Resistive Loads
- Constant energy draw
- Easy to calculate
- Examples: lights, heaters, toasters
Inductive Loads
- Require surge power
- Generate reactive currents
- Examples: pumps, fridges, drills
Inductive loads can distort voltage output if not managed correctly. Assos Power uses this info to recommend generator models with adequate AVR (Automatic Voltage Regulation).
Step 4: Consider Load Diversity and Usage Pattern
Not all devices run at the same time. Understanding load diversity helps you reduce unnecessary oversizing.
Ask yourself:
- Will all machines be operating simultaneously?
- Are there peak and low load times?
- Can some equipment alternate usage?
Assos Power assists clients in developing load management strategies so they can rent a smaller, more efficient generator without compromising performance.
Step 5: Factor in Operating Hours and Duty Cycle
Short-term and long-term rentals have different needs.
- Events need high load for short durations (6–12 hours)
- Construction may run heavy machinery for 8–10 hours daily
- Off-grid backup could require 24/7 output over weeks
If your load is constant and high, you’ll need a prime-rated or continuous power generator.
Assos Power rents generators based on duty cycle and daily runtime to reduce strain and extend fuel intervals.
Step 6: Include Extra Capacity for Safety Margin
Adding a buffer prevents stress on the generator and accounts for unexpected devices.
Standard buffer: 15–25% above total calculated load
Example:
If your total demand is 15kVA, aim for a 20kVA generator.
Assos Power always includes a safety margin in its calculations to prevent overloads and ensure smooth operation under fluctuating loads.
Step 7: Understand Fuel Consumption and Refuelling Needs
Each generator consumes fuel differently, depending on size and load percentage.
Diesel generator example:
- A 30kVA unit might burn 5–6 litres/hour at 75% load
- Running it for 10 hours/day = 50–60 litres/day
Accurate load matching helps Assos Power determine:
- Tank size requirements
- Refueling frequency
- Delivery planning
This reduces downtime and keeps fuel costs predictable.
Step 8: Review Site Conditions and Power Distribution Needs
Knowing your layout matters just as much as knowing your load.
Key factors include:
- Distance from the generator to the load
- Cable length and gauge
- Number of distribution boards or connections needed
- Indoor vs. outdoor environment
Assos Power visits large sites to map out proper cable runs and offers complete distribution board setups with your rental.
Step 9: Evaluate Noise, Emissions, and Compliance
For residential zones, events, or sensitive spaces, you’ll need to consider:
- Noise levels (especially at night)
- CO2 and diesel emissions
- Health and safety compliance
Assos Power offers silent generator models with low-noise enclosures and provides guidance on ventilation and placement.
Step 10: Let Assos Power Help You Run the Numbers
Doing the math solo can be confusing, especially for larger jobs. That’s why Assos Power offers free load assessment consultations with every rental inquiry.
Their team assists with:
- Load audits
- Generator sizing
- On-site surveys
- Fuel planning
- Connection setup
This ensures you get the most efficient rental unit for your actual usage, not just a guess.