How to Calculate Size Of Inverter Needed For Installation In Homes and Offices

 Many people want a power backup plan or solar system installed in their home without knowing the type of inverter to use. Most are ignorant and naive of the inverter supply peak power and typical power.
All these are explained below:

Appliances such as those with electric motors need high startup surge. This can be referred to as surge power which is the maximum power an inverter can supply for a short time.

When a refrigerator is turned on, the power it ‘pulls’ at first is referred to as SURGE POWER. The power that is supplied on a steady basis afterwards is called CONTINUOUS RATING or typical power.

Forging ahead, let’s calculate the inverter size you need for your home in the following steps:
First, what load do you intend to power? Let’s say 1TV (125W), 8 bulbs (15W each), 2 Fans (56W each), 1 Decoder (25W) and 1 Laptop (85W).

1. Calculate the total wattage

The total power needed will be calculated as “Power = Wattage of all appliance x Quantity.” Therefore, you’ll need a total power of (125×1) + (15×8) bulbs + (56×2) fans + (25×1) decoder + (85×1) = 467Watt.

2.    Calculate the inverter's required capacity.

Now, let’s calculate the inverter’s required capacity, i.e the Volt-Ampere rating. In an ideal condition, an inverter would operate with 100% efficiency. Most inverters have an efficiency of between 60% and 80%. This efficiency can also be referred to as the power factor of an inverter. For our calculations, we would use a power factor of 0.8. Hence,
Type of inverter = Total wattage / power factor or adjustment factor

Power supplied (or VA rating of the inverter) = Power consumed by equipment in watts / Power factor

Recall, the total power consumed by your home (total wattage) – 467W.
Power factor = 0.8

Therefore, required VA rating of inverter = (467/0.8) = 583.75VA.
Adjustment factor or power factor = 25/100 or 0.8

This is approximately a 0.6kVA (600VA).

Using a 0.6kVA inverter will be inappropriate considering surge power and the probability of adding a few small appliances to the system. A 0.8KVA or 1KVA inverter will be suitable for your home.