GENERATOR SETS, FREQUENTLY ASKED QUESTIONS
Let’s raise in this paper, a series of frequently asked questions about the operation of a generator, and some of the most complex concepts about their characteristics. We will try to resolve each of these questions in a clear and concise manner.
Obviously these answers are not intended to be exhaustive, as it could result in an excessively long text.
Let’s go with the questions and answers.
INDEX OF QUESTIONS
- What is a generator?
- How does a generator set work?
- What are the most common components in a generator set?
- What is a control panel for?
- What is a thermal circuit breaker for?
- What is a transfer switch?
- What are the RPM in a generator?
- Does the power change depending on the Hz being the same alternator?
- What is the difference between Stand By and Prime Power?
- What is a synchronized generator?
- What happens if I overload a generator?
- What happens if I use a genset below capacity?
What is a generator?
A generator set is an electric machine consisting mainly of a motor (mostly diesel or gasoline), an alternator and an electrical control panel. And it serves to supply electrical energy, when a power failure occurs or in isolated places where there is no mains supply.
How does a generator set work?
A generator set is a rotary electric machine that transforms mechanical energy into electrical energy. Thanks to the engine and the alternator, they achieve through the interaction of the two elements, convert the mechanical energy into electrical.
The alternators generate electricity in alternating current through a moving part called a rotor, which will rotate by the mechanical force exerted by the motor, and a static part called the stator.
When a generating set is in operation, one of the two parts generates a magnetic flux (acts as inductor) for the other to transform it into electricity (acts as induced).
What are the most common components in a generator set?
All generators are made up of different elements. The following are the most common components present in most of these devices:
- Fuel Tank
- Control Panel
- Line Breaker
- Refrigeration System
There are many extra components, which give the generator set the ability to adapt to the specific needs of each customer. These components are manufactured and installed directly by the manufacturer of the generating set, clear examples are, wheels, soundproof cabs, hydraulic systems of elevation of the generating set, etc.
What is a control panel for?
The main function of the control panel is to control generator set operating parameters and to protect it against possible faults. They are digital and can have communication ports that allow them to connect to local or distant computers offering a wide range of monitoring and control possibilities.
What is a thermal circuit breaker for?
The thermal circuit breaker is a safety and protection accessory that allows to cut the current in case of overload. It prevents the heating and overload of the engine and the alternator, as well as the short circuits.
What is a transfer switch?
The transfer switch is a device in charge of switching or changing the main source of electrical supply, from the general connection to the generator set and vice versa, when a cut occurs or the supply is restored.
There are currently two types of switches: manual and automatic.
FREQUENTLY ASKED QUESTIONS BEFORE BUYING A GENERATOR
What are the RPM in a generator?
RPM stands for Revolutions Per Minute and refers to the number of times the engine turns every minute. Therefore, a generator set with an RPM value of 3000 operates at twice the speed of the generator set at an RPM of 1500. When a generator has a four-pole alternator and a frequency of 50 Hz, the normal speed is Of 1500 RPM, and when the frequency is of 60 Hz, the habitual speed is of 1800 RPM.
Does the power change depending on the Hz being the same alternator?
Yes. Because the engine goes from 1,500 revolutions to 1,800 revolutions. It gives more strength and consumes more even though it is the same alternator. The Hz change will also give more amps and the voltage will also rise.
What is the difference between Stand By and Prime Power?
The difference between Stand By and Prime Power depends on the type of use you want to give your power generator. If your equipment is going to be destined to deliver emergency energy (ie during outages in the Commercial Network), we will talk about the “Stand By” Power. If your equipment will be destined to operate in an uninterrupted way without limit of annual operating hours (ie instead of the Commercial Network), we will talk about “Prime Power”. In both cases it is assumed that the load applied to the power generator is variable over time.
As a general rule a device in use in “Stand By” can withstand a greater load than a generator in “Prime Power”.
What is a synchronized generator?
A synchronized generator is one that has a voltage, frequency and phase sequence, equivalent to the mains, one or more generators, or both.
This allows depending on the configuration, to connect one or several generators to a power failure, to the failure of one of the generators, to the other equipment being started and even the connection of one or more equipment to a Increased demand for energy in the electricity grid.
The synchronization increases the final price of the generator set due to the need to install a control panel that allows automatic synchronization, but provides greater security to the installation.
What happens if I overload a generator?
The genset should not be overloaded once it is in operation, although they are designed to withstand overload conditions for a short time during group start-up. If a generating set is operated for a long time under overload conditions (ie at a rate above the maximum generator set rate) several things may occur.
Among what may occur are:
- Cooling system overheating
- Alternator coil reheating
- Decrease in oil viscosity (thickness) with resulting loss of oil pressure.
- Reduced generator set life
What happens if I use a genset below capacity?
All engines are designed to work under different load conditions, from maximum to minimum. Problems occur when the engine runs at low loads (minimum load) for a long time, causing it to not reach its normal temperature. The oil that is normally burned in the cylinder will heat up forming a layer of sediment in the cylinder liner. If low loads continue to work, blue smoke will appear and the engine will need to be serviced to remove the sediment layer from the jacket or to replace it.
YOU NEED ADVICE ABOUT FACILITIES WITH GENERATORS?
In Tecnics Grupos Electrógenos, S.L. We have over 30 years of experience in the design and manufacture of generator sets and a large technical team specialized in all types of installations with generators.