Kilowatts or amps are familiar to most people. But when renting or buying a generator or genset, people often talk about kVA. But what exactly is kVA? And how can you calculate how much you need for your generator?
KVA is the abbreviation of kiloVoltAmpere and indicates electrical power. Just like watts. Here, you can assume that 1 kVA equals 1 kW (kiloWatt). In practice, it often works slightly differently. This is because watts are used to indicate the power consumed and kiloVoltAmpere is used to indicate how much current is required to do so. And there is a difference in that.
This is because apparent power is involved. Not all the power can be used. This is because the power supplied consists of an active power (effective) and a blind power (non-effective). How much power can be used effectively is indicated by a power factor (pf). This is usually around 80%.
Converting KvA to kW or watts is very simple:
1 kVA = 0.8 kW
1 kVA = 800 watts
Note! We use a power factor of 0.8 in the above. In practice, this can of course also be a pf of 0.6 or 0.9.
The number of kVA you need depends on the total kilowatts your equipment consumes. You therefore need the full power. Do your appliances collectively consume 10kW? Then you will need 10 / 0.8 = 12.5 kVA. And does your equipment operate at 10 amps? Then the power is 10 x 230V = 2300 watts (or 2.3 kW)*. So in that case, you will need 2.3 / 0.8 = 2.875 kvA.
*However, a connection is not always 230V. With heavier equipment, for instance, you use a 400-volt high-voltage connection. Appliances that require power current and operate at the same 10 amps will then have a capacity of 10 x 400 = 4000 watts or 4 kW. You will then also need 4 / 0.8 = 5 kVA!
When determining how many kiloVoltAmps are needed, also take the peak current or peak load into account. This is because some electrical equipment requires (much) more power when starting up than when running for a while. If you then connect appliances to a generator with just enough power, you may run out of power. Especially if you start several heavy appliances at the same time.
So how many kVA your genset should be depends on how much voltage you need (230V or 400V) and the combined capacity of all the equipment you connect to the generator at the same time. By default, you then need a little more to cope with moments of peak load. Check the model specifications for the exact power output of our models.
