Glossary

EMERGENCY POWER SUPPLY
An independent backup source of electrical energy, which, in the event of failure or failure of the main source, provides power supply of the required quality and quantity to continue the operation of the user’s equipment.

AUTOMATIC SWITCH
A protective switch is a device that opens the current flow circuit at a predetermined value.

AUTOMATIC SYNCHRONIZER
This device in its simplest form is a magneto-controlled relay that automatically closes the generator switch when the synchronization condition is reached.

AMPERE (A)
The unit of measurement of electric current strength. The current is equal to one Ampere when it flows through a conductor with a resistance of 1 Ohm at a voltage of 1 Volt.

WATT
Unit of measurement of electric power. In the case of direct current, it is equal to the product of the voltage in Volts and the current in Amperes. In the case of alternating current, it is equal to the product of the effective value of the voltage in Volts, the effective value of the current in Amperes, the power factor and the constant, which depends on the number of phases.

OSCILLATOR
A device that converts alternating current into direct current.

GENERATOR
The general name of a device for converting mechanical energy into electrical energy. Direct or alternating current can be used as electrical energy.

HERTZ (HZ)
See Frequency

ACTUAL POWER
A term used to describe the product of current, voltage, and power factor. It is expressed in kW.

DECIBEL (DB)
The unit of measurement of noise level.

FREQUENCY RANGE
Permissible frequency deviation from the average value in the state.

FREQUENCY DRIFT
Frequency drift is a gradual increase or decrease of its average value under constant load.

CAPACITY (C)
If a voltage is applied to two conductors separated by an insulator, the insulator will acquire an electrical charge. It is expressed in microfarads (μF).

INDUCTANCE (L)
Any device that contains iron has some magnetic inertia. This inertia prevents any current changes. The circuit characteristic that causes this magnetic inertia is known as self-inductance. It is measured in henries and denoted as L.

UNINTERRUPTED POWER SUPPLIES (UPS)
A system to provide power without delays or transients at any time when it is not possible to supply the main power supply with the necessary parameters.

APPARENT POWER (KVA, VA)
A term used when current and voltage are in different phases, ie. voltage and current do not reach the corresponding values ​​at the same time. As a result, they talk about the power that appears and express it in kVA.

KVA
1000 Volt-ampere. Corresponds to kW power divided by the power factor.

KVT
1000 Watts (real power). Corresponds to kVA power multiplied by the power factor.

TELEPHONE LINE INFLUENCE FACTOR (TIF)
The coefficient of influence of a synchronous generator on telephone lines is a measure of the possible influence of voltage harmonics produced by the generator on telephone circuits. TIF is measured at the terminals of the generator in idle mode at the nominal values ​​of voltage and frequency.

POWER FACTOR
In AC circuits, inductances and capacitances can form a point where the zero-crossing voltage and current waves are out of phase. When the current leads the voltage, we talk about the power factor corresponding to the lead or the capacitive nature of the load, as well as the excitation of synchronous motors. When the voltage leads the current, the power factor corresponding to the lag is said. This is a general case. The power factor is equal to the length of the segment where zero voltage differs from zero current. Considering the period equal to 360 degrees, the difference in the position of the zeros can be expressed as an angle . The power factor is calculated as the cosine of the angle between zero points and is expressed as a decimal fraction (0.8) or percentage (80%). It can also be expressed as the ratio of power in kW to power in kVA. In other words: P(kW) = P(kVA) × cos φ.

THE POWER FACTOR IS UNITY
A load whose power factor is equal to 1.0 does not have a reactive component, which causes the voltage wave to lag or lead the current wave.

POWER
The speed of doing work or energy per unit of time. Mechanical power is often measured in horsepower and electrical power in kilowatts.

CONTINUOUS LOADING
Any load, the value of which does not exceed the nominal, which this generator can provide for an indefinite period of time, except in cases of shutdown for maintenance.

CAPACITY
Installed or guaranteed pure electric power continuously obtained from the generator set when operating under normal conditions. If the unit is equipped with additional equipment for obtaining energy, then the electrical power of this equipment must be taken into account when calculating the nominal power, unless this condition is determined otherwise.

NOMINAL SPEED OF ROTATION
The number of revolutions per minute for which the unit is designed.

NOMINAL VALUE OF CONTINUOUS LOAD
The rated load of an electrical generating system that this system can supply without exceeding the specified maximum temperature limits.

NOMINAL VOLTAGE
The nominal voltage of the generating set is the voltage for which the unit is designed.

NOMINAL CURRENT
The rated continuous current of the installation or equipment defines the rms value of the alternating current or the amount of direct current in Amperes that can be maintained under normal operation without exceeding the established temperature limits.

MONOPHASE
An AC load or source usually has two input or two output terminals, respectively.

PRIMARY SOURCE OF FOOD
A source of electricity that is used continuously throughout the day and night. Usually provided by a utility, but sometimes by your own installation.

ALTERNATING CURRENT
An electric current that periodically changes its direction and amplitude when flowing through a conductor or circuit. The magnitude of the alternating current increases from zero to a maximum value, then returns to zero, and then the same thing happens in the opposite direction. One complete change occurs in a period or 360 degrees. In the case of an alternating current with a frequency of 50 Hertz, the direction of the current changes 50 times per second.

PERIOD
A complete change in AC current or voltage from zero to positive maximum, zero, negative maximum, and zero again. The number of periods per second is the frequency, the value of which is expressed in Hertz (Hz).

DIRECT CURRENT
An electric current that flows in only one direction at a given voltage and resistance. The magnitude of the direct current is usually constant for a particular load.

INTERRUPTABLE MODE
The operating schedule of the device is made depending on the utility power supply mode for a specific user. This schedule is agreed upon by users.

REACTIVITY
The phase component of the impedance. There is in the presence of inductance and/or capacitance in the circuit.

STAR CONNECTION
The method of connecting phases in a three-phase system. A fourth or neutral conductor may be connected to the middle point.

TRIANGLE CONNECTION
A three-phase connection in which the beginning of each phase is connected to the end of the next. The load is connected to the corners of the triangle. In some cases, a central lead is made in each phase, but most often it is made in one arm, providing a four-wire connection.

FREQUENCY FALL
The change in frequency between the no-load value and the full-load value, which is a function of the engine and control systems.

AVERAGE EFFECTIVE PISTON PRESSURE
This is the theoretical average pressure on the piston of the engine cylinder during the working stroke, when the engine develops a given power. Usually expressed in pounds/inch^2. Calculating this is difficult, since the actual pressure in the cylinder is constantly changing. Average pressure is used to compare engines on the assumption that the lower the average effective pressure per piston, the greater the expected life and reliability of the engine. In practice, there is no reliable indicator of engine performance for the following reasons: the formula is better for evaluating older engine designs that have relatively low power per cylinder displacement compared to more modern designs. Modern engines operate at higher average cylinder pressures, but bearings and other engine parts are designed to withstand these high pressures and provide the same or greater life and reliability than older engine designs. The formula also gives an increased reliability value when the same engine produces the same power at a higher crankshaft speed. All other things being equal, it is unlikely that a generator set rated at 60 Hz and operating at a rotation speed of 1800 rpm is more reliable than a generator set rated at 50 Hz and operating at a rotation speed of 1500 rpm. It is also doubtful that a generator set operating at 3,000 rpm is more reliable than such a unit operating at 1,500 rpm, even if the latter has a significantly larger mean effective piston pressure.

The mean effective piston pressure for a particular generator set will vary with fuel, temperature and altitude dependent parameters. The value of the average effective pressure on the piston also affects the efficiency of the generator, which varies depending on the amount of voltage and load.

MEAN SQUARE VALUE
Used to measure alternating current and voltage. It is a characteristic of a sinusoidal wave.

AMBIENT TEMPERATURE
The temperature of the environment in which the generator system operates. Can be expressed in degrees Celsius or Fahrenheit.

CURRENT
Electricity flow. Direct current flows from the negative pole to the positive pole. Alternating current changes its direction. Theoretically, when calculating current and power, the generally accepted direction is from the positive pole to the negative pole.

FULL LOAD CURRENT
The full load current of the unit or equipment is the rms value of the alternating current or the value of the direct current, expressed in Amperes, when the rated power is reached under normal conditions. Usually the full load current is the “rated” current.

THREE-PHASE
Three voltage/current sine waves with a period of 360 degrees and an offset of 120 degrees between them. A three-phase system can be either 3- or 4-wire (3 phase conductors and one neutral).

FREQUENCY
The number of complete periods of alternating current or voltage per unit time, usually a second. The unit of measurement is Hertz (Hz), which is equal to 1 period per second.

EFFICIENCY
The efficiency of the generating unit is defined as the ratio of its useful power to the total power, expressed as a percentage.