Useful terms:

Voltage: difference in potential between two points of an electrical circuit. Measured in volts (V)
Current: intensity of the flow of electrons around an electrical circuit. Measured in ampere (A)
Frequency: number of times that an alternating current reverses its direction in one second. Measured in hertz (Hz)
Resistance: the resistance that an electrical circuit opposes to the flow of electrons. Measured in ohms (?)
Power: electrical energy supplied or absorbed by an electrical appliance within a fixed time. Measured in watts (W) or in volt-amperes (VA)
Power factor: ratio between real power (W) and apparent power (VA). Indicates the difference in phase between the voltage and the current and depends on the powered appliances. It is a pure number represented by cosf.
The power absorbed by the appliance can be calculated in the following way: the appliance data plate shows the cosφ.

Single-phase appliance: W: V x A x cosφ (power factor)
Three-phase appliance: W: √3 x V x A x cosφ (power factor)

230 volt single-phase and 400 volt three-phase voltage with neutral:

A 230 V purely single-phase generating set will have full power in the blue single phase sockets supplied as standard. A 400 V three-phase set always has a single-phase output but full power is achieved in the three-phase socket while, in the single-phase socket, as the power is derived, it is 40%. EXAMPLE: Energy set model EY-10TDE: 10 kVA in three-phase and 4 kVA in single-phase. On request, for a small extra charge, it is possible to have generators where the single-phase is reinforced at 50% or 60%. In any case, the power available in single-phase is equal to the current value declared in the flow in amperes shown on the 2 pole 230 V single-phase circuit breaker.

Difference between 3000 rpm and 1500 rpm:

A 3000 rpm generating set is more suitable for emergency and sporadic uses only. Its working life is shorter than a 1500 rpm model with the same power rating, it produces more vibrations and is much noisier. It should also be noted that the cost of the 3000 rpm models is considerably lower than a 1500 rpm generating set. The petrol models are all 3000 rpm, 1500 rpm versions do not exist. We refer to the 1500 rpm models as “industrial” as they are more reliable and suitable for continuous operation. With correct maintenance, they last much longer than the 3000 rpm versions.

Difference between air cooling and water cooling:

A generating set with a water-cooled engine is certainly of a higher quality than one with an air-cooled engine. It has a closed circuit radiator and is cooled with liquid coolant. This keeps the temperature more constant and the engine is also quieter than the air-cooled one, making it more advisable for the silenced versions. A generating set with an air-cooled engine is cooled using a forced fan which cools the cylinders. As there is no radiator, it requires less maintenance. For the silenced version, is more recommended the Water cooled engine version.

Difference between a generating set with a petrol engine and one with a diesel engine:

It is important to say that the largest generator with a petrol engine that we produce is 12 kVA. For greater power ratings, diesel generators are the automatic choice. There is a substantial difference between petrol and diesel generating sets. Petrol models produce fewer vibrations and are less noisy than diesel models. A petrol generating set weighs less, is smaller in size and easier to pull start with the manual starting with rope. It is suitable for an emergency use. Compared to a generating set with a diesel engine with the same electric power rating, the cost is considerably lower. The diesel model, on the other hand, consumes less, is more reliable, is suitable for more heavy duty work and lasts longer over time. It is therefore advisable to be aware from the start how many hours the generator will have to work in order to make the best choice.

How to choose the right model based on the type of load to be powered:

In order to be certain of making the right choice regarding the power rating of the generating set, it is necessary to determine whether the load to be powered is resistive or inductive, identify how much the appliance absorbs in kVA or kW in nominal conditions and choose the most appropriate ENERGY model.

The power ratings of our generating sets are calculated as follows:

Per ottenere il valore della potenza attiva in W o kW occorre moltiplicare il valore del cosφ per il valore della potenza apparente in VA o kVA. Gruppo elettrogeno con tensione monofase: 1000 VA x cosφ 0,9 = 900 W – 1 Kva x cosφ 0,9 = 0,9 kW Gruppo elettrogeno con tensione trifase: 1000 VA x cosφ 0,8 = 800 W – 1 Kva x cosφ 0,8 = 0,8 kW

IMPORTANT:
The electric power rating of the generating set must not be lower than the sum of the power ratings (kW) of the loads to be powered. It is highly advisable to oversize the power rating of the generating set to be chosen by 10-15%. If the load that the generating set is to power is a series of inductive loads, therefore having high inrush currents in the initial moment, the set to be installed must have a power rating which is at least twice that of the sum of the power ratings (kW) of these loads which will have to be started up at the same time. N.B. For electric motors: 1 kW = 1.34 HP.

Calculation from HP a kW: HP : 1,36
Calculation from kW a HP: kW x 1,36

Resistive loads:These are made up of resistors, electrical components characterised by a resistance which develops energy in the form of heat as the current passes. Examples include light bulbs, heaters, electric ovens and irons..

Inducutive loads:These are characterised by the presence of inductances, electrical components which develop energy in electromagnetic form. Examples include electric pumps, electric motors, fridges, electric gates, air conditioners, compressors, concrete mixers, fans and drills