VA (Voltampere) is the term about how much power an electrical circuit unit can provide. 1 VA is similar to 1 W (Watt). This means if a transformer have 15 kVA then it can provide at most power up to 15 kW power. Effectively the load you can really connect to a such transformer is about 10% to 20% lower because of the blind load. In the Philippines better calculate with 20% because the appliances have not the quality and efficiency of US and European appliances.