Sizing: Calculate your power needs

Properly sizing your generator is essential and it requires the analysis of the different specifications of the electrical equipment that you have to power, which we will call the "load". Let's check together some advices.

COMMON MISTAKES

A fairly common mistake is underestimating the power required, often because the real starting power of the load is unknown and not considered in the calculation. Connecting a generator to loads greater than its nominal power causes an overload. When a generator is overloaded, the engine speed drops and the voltage and frequency become unstable until the generator stops, or worse, if the overload is high and the generator is not equipped with protective devices (e.g.: a good circuit breaker, engine protection card etc..), it can damage the devices is connected to and the generator itself.

Oversizing a generator power too much is also a mistake and you should never run a generator with a load below 30% of its rated power.

The ideal would be to stay on 70/80% of the nominal power of the generator to avoid overload and have margin for any physiological increases in the power demand over the years.

CHECK ALL THE TECHNICAL LABEL
To calculate the electrical load of your home, commercial or artisan business, you must first check all the technical label for each appliance you want power and read the power in Watts (remember: 1000 Watts = 1kW).
It is necessary to distinguish between starting power, i.e. the power necessary to start a machine, and nominal power, i.e. the power required to run in continuous.
The power required to start your appliances or tools does not always correspond to the nominal power found on the label, but depending on the product category it will be necessary considering a starting power peak, classic example: 1kW air conditioner to start it will require a power greater than one and a half times, i.e. 1.5kW x1.5 = 2.25kW.
This peak normally lasts a few seconds and mains power is very flexible in giving a greater power without reaching a power cut. The generator set on the contrary, as explained above, does not deliver more power than what is declared on the data plate.

HOW TO CALCULATE STARTING POWER
Here you can find an indicative load table that you can fill in by entering your loads and calculate how much power, including starting power, you need.

OPTIMIZE THE POWER OF YOUR GENERATOR
Evaluations can obviously be made to optimize the power of your generator and save money, such as:
- Start the loads in sequence. This can be done by the electrician who installs the generator.
- Consider only the starting power of the load with greater total power and start the other loads in sequence.
- Decide that in the event of a blackout, only some selected loads will be powered by the generator, while other non-essential loads will remain off. Obviously, this can be done when the electricity grid is reliable and the power failure is only a short-term emergency.

ATTENTION!
ALTITUDE AND TEMPERATURE can cause a lowering of the power produced by the generator (even by 20%), from 1000m altitude and over 35°C it is necessary to consider an increase in the power of the generator.
Always specify these information when purchasing the generator so your dealer can consider correct derating.

These tips are general guidelines, especially suitable for small or medium power machines, asking your electrician for support is essential to be sure of correctly calculating the required power.

The next issue of the Technical Info Review is entitled "Focus on the Engine".

We will deal with the typical failures that can occur on the engine, how to identify them and how to solve them.

EGPS Ltd specialists in the supply of quality diesel and petrol powered generators in Ireland.

We offer an extensive range which covers mains failure generator sets for small and large domestic properties, portable and static sets for use in construction.

We supply quality generators that are built based on the world’s finest diesel engines from John Deere. Perkins, Iveco and Cummins , Scania, & Yanmar. with full-service support. Our experienced team are always available to offer help with choosing the correct diesel generator for the application. We are happy to answer any questions you may have. Add in above names.

EGPS Ltd operates a hire fleet ranging in size from 3KVA TO 1000 KVA , in addition we also supply bunded fuel tanks and cables when required.

Contact Our Sales team today.

Tel: 0504 44437

Email: Info@egps.ie

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