Guaranteed power supply is reliable protection from blackout of premises, loss of important data, failure of life support equipment. It is relevant in everyday life and for solving business problems, and protects against the unpleasant consequences of a power outage. With its help you will save all important data and ensure normal operation household appliances and electronic equipment. Guaranteed power supply will allow you to install optimal system life support, independent of external circumstances.

The Vega company sells modern inverter-battery systems with OutBack Power and Victron Energy power inverters. They are suitable for objects of various scales: from country houses to medical and office centers, banks, cinemas. With their help, you will provide guaranteed power supply to both individual electrical appliances and the entire facility.

What are the benefits of installing OutBack Power and Victron Energy systems?

Professional power inverters OutBack Power and Victron Energy will provide a guaranteed power supply system at the facility under your control. This way, your power grid and server installations will not be affected by a loss of external voltage.

Guaranteed power supply provides maximum protection, first of all, from network power outages, as well as from power surges and surges.

All risks associated with a sudden loss of power supply to the central network are minimized.

Systems are suitable for:

• cottages, country houses, individual residential properties;
• medical centers, clinics, private offices;
• kindergartens, schools, sports clubs, social security institutions;
• business and shopping centers, offices, industrial and municipal facilities;
• entertainment centers, establishments catering etc.

Operating principle of guaranteed power supply

The source of guaranteed power supply is an inverter (DC/AC converter), connected to a powerful block of special batteries (AGM or GEL). They are recharged from the central power supply network using a multi-stage built-in inverter charger. When the main network fails, the inverter automatically switches the batteries from storage mode to electricity consumption mode. Instant switching allows you to provide power to all active systems without interruption in their operation.

The guaranteed power supply system allows the connection of generators to the inverter, solar panels and other external energy sources.

The backup power supply time depends on the number of batteries and load power.

Categories of consumers who need guaranteed power supply

All electricity consumers who require constant power supply, in the event of a failure or shutdown, switch to backup power systems. Consumers are categorized by importance.

• life and health of people;
• state security;
• material resources of special importance;
• industrial and municipal structures.

• life and health of people;
• emergency control and fire safety at strategic sites of special importance.

• disruption of production and operation of large industrial and agricultural facilities;
• downtime of equipment, transport, labor resources;

This article is intended for practitioners who have to deal with the problems of ensuring high-quality power supply to security systems.

Terminology and abbreviations that will be used in this article:

• battery— sealed acid battery with gel electrolyte.
• GENERATOR- diesel or gasoline power plant, generating alternating single-phase voltage 220 V or three-phase 380 V.
• INVERTER- uninterruptible power supply device based on conversion DC from batteries to alternating single-phase voltage 220V or three-phase 380V. It is implied that
• INVERTER contains battery necessary to ensure the required operating time at a given power.
• UPS— this abbreviation will mean “computer uninterruptible power supply” of low power.
• UPS— Sources uninterruptible power supply(or IVEPR— secondary power supply sources are redundant).
  Such devices are designed to power equipment that does not have its own built-in power supply. Included UPS included battery.
• IRP— Backup power supplies. Designed to provide power to equipment that has its own main power source and an input for additional redundancy.

CHOOSING A CATERING STRATEGY

First of all, consumers should be divided into groups according to the criticality of the power supply and the required backup time.

• - Relatively low cost - on average gasoline generator will cost $400-500 per kW, and diesel is about 1.5 - 2 times more expensive;
• — High quality output voltage;
• — Possibility of long operating time.

Flaws:

• — special premises are required;
• — need for maintenance;
• — inability to provide uninterrupted power supply — it takes time to start the generator.

Diesel generators are cheaper to operate, so it makes sense to use them only for organizing long-term backup power to facilities high power(more than 5 kW). At lower powers or for short-term use, a gasoline generator will be more economical.

Buy GENERATORS It only makes sense to import them and only from specialized companies. Many good brands of Japanese (eg Yamaha), French (SDMO) and Italian production are imported to Russia.

INVERTER- this is what is usually called a converter with low voltage DC to High AC. In other words - energy battery AC 220 V. V pure form inverters are rarely used, but are integral part uninterruptible power supply systems, which are usually called UPS. UPS There are two types - on-line and off-line. UPS off-line are cheaper and simpler - the inverter turns on only when the mains voltage fails. The on-line circuit is a double conversion circuit. First, the mains voltage is reduced and rectified, after which the direct current is converted into alternating 220 V using an inverter. When the mains voltage fails, energy is used battery. Such a circuit provides the highest quality power, since it does not depend on the quality of the input voltage. On-line inverters are both voltage stabilizers and filters. This perfect solution to provide 220 V power to consumers. But they also cost significantly more than conventional off-line devices.

Another important parameter for INVERTERS And UPS is output waveform:

• - pure sine - the most complex and expensive devices;
• - approximated sine - an intermediate option, maybe varying degrees approximations;
• - modified sine, meander, quasi-sine - the most common and inexpensive option inverter

It must be remembered that some types of loads are very sensitive to the shape of the supply voltage. The modified sine cannot be used to power consumers with transformer power supplies and sensitive equipment.

Output power - for inverters it is usually indicated in Volt-Amps (VA, VA). Unlike Watts (W, W), which indicate the effective power consumption AC, volt-amperes characterize the amplitude values ​​of currents and voltages in the load. The existence of such a unit is due to the fact that phase shifts can occur in alternating current circuits.
For a simple resistive load VA = 1.41 x W
It is extremely careful to connect a load with a power indicated in Watts to a source whose power is indicated in VA. If such a need arises, then for calculations multiply the load value in Watts by 1.41
Purchasing good INVERTER — big problem. There are very expensive models, intended for telecommunications and computer equipment.
Virtually absent from the market " middle class" As a rule, problems with the service, and INVERTER- a very expensive and complex device.
There are good domestic devices, but their manufacturers - defense factories - suffer from poor marketing. Buy a computer UPS small power is as easy as shelling pears.

LOW-VOLTAGE UPS and IRP

Almost all IRPs existing on the market are similar to each other and differ only in the capacity of the installed batteries.
Therefore, we will focus on UPS. Based on their circuit design, UPS can be divided into transformer and pulse.
In turn, transformer UPSs can be equipped with a linear or PWM stabilizer.
Switching UPSs for security systems are rarely used due to low reliability and high level interference
Transformer sources with a linear stabilizer are optimal for low currents.
At high currents, PWM stabilizers are increasingly being used, although linear circuits are still unrivaled in terms of reliability and maintainability.

One of the most important parameters— MAINS SUPPLY VOLTAGE. In Russia, the standard for electrical networks allows a voltage range of 187...242V (220V -15% +10%).

Foreign requirements are more stringent, so imported UPSs are not recommended for use in our networks. Moreover, some domestic UPSs are produced with parameters declared in the range of 220V ± 10%.
The use of such UPSs in real networks is fraught with either chronic undercharging of the battery or failure of stabilization, which is completely unacceptable for security systems. Because in many regions, low voltage in the network is normal condition, UPSs with an extended power supply range of about 150...250V have appeared on the market.

The lack of clear standards for UPS leads to arbitrariness in definitions and terminology, which often confuses the consumer.
It must be remembered that the main parameter of the UPS that characterizes its load capacity is the RATED OUTPUT CURRENT - this is the current that can be supplied to the load when powered from the network ALWAYS, regardless of the circumstances, arbitrarily long time and while maintaining the level of ripple - at any permissible network voltage in the range of no worse than 187...242 V, at any condition of the battery, in the permissible operating temperature range. This is the only current you can count on when building a system.
Often, UPS manufacturers indicate as the main parameter the current supplied to the load without a connected battery (sometimes called the maximum current),
but we must remember that part of this current is taken away to charge the battery, and only the rated current can be guaranteed to be supplied to the load.

All professional UPSs have protection against deep battery discharge. Often UPSs allow you to connect additional power sources to increase the operating time in reserve mode.
Many UPSs have increased output currents in standby mode (in the absence of a network) or for a short time, which makes it possible to significantly optimize the power supply to alarm systems, warning and fire extinguishing systems.

You should choose a UPS or IRP only of domestic production and only from manufacturers specializing in the production of UPS.
It has already become a saying that “only lazy people don’t make power supplies.” But in reality there are no more than 4-5 companies in Russia that produce reliable and proven sources, provide a wide range of products, technical support and a distribution network.

The work of most modern organizations is based on the use of technology that is sensitive to energy quality. Failure of computers, banking and medical equipment, automation systems and other devices entails serious consequences, which can sometimes be irreparable. The existing food system is imperfect and the supply process may suddenly be interrupted. To prevent this from happening, it is recommended to use:

• uninterruptible power supply systems (UPS), the operation of which is based on uninterruptible power supplies (UPS, UPS);
• guaranteed power supply systems (GPS), the operation of which is based on diesel generator power plants (DES, DGU);
• uninterruptible and guaranteed power supply systems, as a combination of the two above systems.

As a rule, the task of ensuring uninterrupted power supply is assigned to the UPS and diesel generators, which take over the power supply for the responsible consumer during the period of absence of electricity in the network. However, in in this case auxiliary solutions also play a role, including redundancy of power lines, fire extinguishing systems and lightning protection. It is important to understand that guaranteed power supply must be provided in any extreme situations.

The key characteristics of uninterruptible power supply systems are reliability, fault tolerance, and energy efficiency. However, saving energy, increasing battery life and increasing equipment efficiency are only part of the solution. Other significant areas include the development of powerful batteries and the use of kinetic storage devices.

Saving resources used

The world is increasingly paying attention to the development and application alternative sources electricity that could be renewed on its own. This is especially important thanks to “green tariffs”, which allow you to sell excess electricity received into the public network, or spend the resulting energy for personal needs, reducing dependence on external sources.

An additional opportunity to save energy resources and increase business efficiency is detailed monitoring of energy costs and automation of processes associated with these costs. Special technologies called the Internet of Things (IoT) can help in this direction. It was thanks to them that the equipment began to work with more “smart” automation, and the collection of information reached a fundamentally new level.

The need for SGP in Russia

In Russia, not only is the issue of electricity supply acute, but there are also problems with the quality of electricity supplied to consumers through general-purpose distribution networks. Therefore, there was a need to create a GPS - a guaranteed food system. It is used in relay protection, automation and process alarm circuits for electrical installations of different voltage classes at energy enterprises and other important facilities.

SGP provides continuous power supply ~ 220V:

• from a centralized AC network ~220V in normal mode,
• from the backup DC network = 220V when the AC voltage is turned off, using the user’s battery reserve,
• from the battery life of an uninterruptible power supply in the absence of voltage, both in the alternating current network and in the direct current network.

Advantages of SGP:

• Stability of network parameters ~220V when connecting =220V with zero switching time to emergency mode without the occurrence of a transient process at the device output.
• The user can independently connect the SGP, since its design is simple and understandable.
• At emergency shutdowns regulatory requirements remain.
• The DC network voltage = 220V in the SGP is produced by three channels of the same type, providing a threefold margin of reliability; if one channel fails during an accident, the SGP remains operational.
• The voltage converter operates in economy mode.
• Operation is practical and durable.

The design of the SGP involves the use of standardized elements: uninterruptible power supply, power supply DC voltage(DC converter), AC relay. If something fails, the part can easily be replaced with a similar one. If necessary, you can contact the service department, but the device is entirely intended for independent use.

What determines the need to use
In our age of rapidly developing information technology the load on existing power supply networks increases significantly. It is becoming extremely difficult to guarantee the uninterrupted operation of telecommunications and computerized systems, and cases of voltage drops and accidents in electrical networks are becoming more frequent. Creating a reliable power supply network will eliminate downtime and loss of important data due to power outages, extend the life of the company's technical infrastructure, and, ultimately, save on costs.

Reliable power supply to commercial, industrial and government enterprises is possible with the help of guaranteed and uninterruptible power supply systems. If you decide to equip a facility with a guaranteed or uninterruptible power supply system, you need to decide on the number and category of consumers who will receive guaranteed or uninterruptible power supply, and the length of time during which autonomous power supply will be provided.

An extract from the PUE (Electrical Installation Rules) provides definitions of the basic concepts relating to guaranteed and uninterruptible power supply systems:

Electricity consumers are a single electrical receiver (ER) or a group of ER, united by a single technological process and located in a certain territory.

Types of electrical receivers:

• ES of category 1 are objects whose power supply interruption is associated with:

Threat to people's lives;
- threat to state security;
- significant material damage;
- disorder of important technological processes;
- disruption of the operation of objects of special importance utilities;
- disruption of communication and telecommunications systems.
ES of category 1 should be provided with power supply using two independent and mutually redundant sources; a short-term interruption of power supply is allowed only for automatic transition to backup power.

• EP1 category of a special group are objects on the uninterrupted operation of which depends the possibility of preventing:

Threats to human life;
- threats of explosions and fires.
A special group should be provided with an additional, third independent and mutually redundant power source.

• EP category 2 are objects whose power supply interruptions lead to:

Massive failure of production;
- downtime (of workers, equipment and industrial vehicles);
- disruption of the work of the urban and rural population.
ES of category 2 in normal mode should be provided with power supply from two mutually redundant independent power sources.

• ES of category 3 are all other objects that do not require backup power. Power supply is provided from a single source with the condition that the period of repair work electrical networks will not exceed 1 day.

Guaranteed power supply system

When using only a diesel generator set (DGS) at a facility as a backup source, the facility is powered using a guaranteed power supply scheme.
Guaranteed power supply supplies electricity when the voltage supply in the main power supply network is interrupted to consumers of the 1st category (according to Chapter 1.2.17 PUE), while the parameters electric current must comply with GOST13109-87.

Guaranteed power supply system:

• Provides guaranteed power supply to connected consumers.
• Automatically starts (with no more than 3 attempts) the diesel generator after 9 seconds from the moment of deviations in the values ​​of the basic supply network from the requirements of GOST 13109-87 and when the power supply is completely stopped.
• Provides automatic transmission external network loads to the diesel generator and vice versa.
• Signals to the control post when emergency events occur with diesel generator equipment.

The facility's guaranteed power supply system must meet the following requirements:

• The MTBF of diesel generator sets must be at least 40,000 hours.
• The capacity load of the diesel generator set should be more than 50%; with less load of the diesel generator set, only short-term operation is recommended, and a load of 30% will entail the supplier’s refusal to provide a warranty for the equipment.
• Emergency start and load acceptance when exiting standby mode in hot standby cannot exceed 9 seconds.
• It is necessary to create conditions for routine maintenance and repair of a diesel generator set while the power supply system is running.
• Required remote control DGU work.
• Completely eliminate the parallel operation of the diesel generator set and the external power supply system.

Uninterruptible power supply system

When using an uninterruptible power supply (UPS) at a facility as a backup source, the facility is powered using an uninterruptible power supply circuit. Consumers using power from a UPS when the main power supply is interrupted are called uninterruptible power supply consumers.

The uninterruptible power supply system provides consumers of the 1st category of a special group with electricity without breaking the sinusoid of the supply voltage, corresponding to GOST 13109-87 (according to Chapter 1.2.17 PUE).

The uninterruptible power supply system provides:

• Uninterrupted power supply without breaking the sine wave of electricity consumers connected via a UPS.
• Fully adjustable output voltage.
• Pure sinusoidal output voltage.
• High system efficiency.
• Compatible with diesel generator sets with a power reserve factor of less than 1.3.
• Maximum protection against shutdowns, surges, surges and power surges.
• Ability to connect multiple UPSs in parallel.
• Autonomous support of electrical load for 20 minutes.
• Uninterrupted load switching through external and built-in bypass to power supply from external power networks.
• Availability of galvanic isolation of circuits (at the input and output).

When creating an uninterruptible power supply system at a facility, it is necessary to take into account certain requirements:

• Due to a single failure of any of the UPS elements, the performance of the system should not be completely disrupted.
• The SBP must have a service life of at least 10 years.
• Neutral cables of incoming electrical networks and transformer substations substations should not be overloaded.
• Regulated maintenance and repair of the UPS must be carried out without interrupting the building's power supply.
• Monitoring of UPS parameters must be remote.
• After the service life of autonomous batteries has expired in the absence of external voltage, technological processes must be completed correctly.

Sharing on-site uninterruptible and guaranteed power supply schemes

When equipping a facility with a diesel generator set and an uninterruptible power supply, the facility is powered using a circuit increased reliability using uninterrupted and guaranteed power supply.

If the main supply voltage is lost, a signal is automatically sent to start the diesel generator set. The diesel generator set starts up within 5-10 seconds when voltage is not supplied to consumers. When the diesel generator set reaches the rated frequency and voltage mode, the power supply to consumers is restored.

When the diesel generator set starts, the UPS switches to batteries. The power supply to consumers during the start-up of the diesel generator comes from the UPS batteries. Thus, a break in the sinusoid of the supply voltage is eliminated.

At the moment the external power supply voltage returns, consumers are disconnected from the diesel generator set and connected to external source. For a short time, consumers of guaranteed power supply remain without voltage; The diesel generator stops and it goes into standby mode.

The possibility of power supply from the diesel generator set for a certain time is determined specific consumption fuel depending on the load and the amount of fuel in the tank. It is possible to refuel the diesel generator set during operation. If the fuel in the fuel tank runs out, the automatic control unit of the diesel generator set will shut down the diesel generator set.

When creating a scheme for uninterrupted and guaranteed power supply at a facility, the following requirements must be taken into account:

• The use of an on-line class UPS, since the load will be protected from all existing problems in the electrical network.
• The power of the UPS must match the load.
• The UPS must include rechargeable batteries. The battery backup time should be at least 5-10 minutes.
• In order to reduce the non-linear current distortion arising from the UPS, the UPS should be used with IGBT active rectifiers or 12-pulse rectifiers.
• It is recommended to choose UPSs that smoothly switch to mains power from the battery.
• The power ratio of the diesel generator set and UPS should be equal to 1.3.
• The diesel generator set must be equipped electronic regulator drive motor speed and automatic output voltage regulator

1.1. The need to create a system

The main problem that one has to face when deciding whether to install a diesel generator set (DGS) and an uninterruptible power supply (UPS) at a facility is ensuring power supply in the event of a loss of voltage from the main supply network of category I consumers and category I consumers of a special group according to PUE.

Unfortunately, in practice, there are frequent situations where the equipment of a distribution transformer step-down substation (RTS 10/0.4 kV or RTS 6/0.4 kV) fails, failures in the area’s power grids, etc. Therefore, 2 inputs from the RTP, as required by the PUE, in practice are not enough and at such facilities there is a need to install a diesel generator station - guaranteed power supply, and uninterruptible power supply sources - uninterruptible power supply.

The guaranteed power supply system serves to provide electricity of the required quality (GOST 13109-87) to consumers of category I (PUE Ch. 1.2.17), in the event of a loss of voltage from the main supply network.

The uninterruptible power supply system serves to provide electricity of the required quality (GOST 13109-87) without breaking the sinusoid of the supply voltage to consumers of category I of the special group (PUE ch. 1.2.17).

2. Description of the solution

2.1. General information

The guaranteed power supply system must provide:
• guaranteed power supply to connected consumers;
• automatic start (at least 3 attempts in total) of the diesel generator after 9 seconds when the parameters of the main external power supply network deviate beyond the requirements of GOST 13109-87 or its complete disappearance;
• automatic load switching from the main external power supply network to the diesel generator and back;
• issuing an alarm signal to the dispatcher's post in the event of an emergency event with diesel generator set equipment

The uninterruptible power supply system must provide:
• uninterruptible power supply (without interruption of the supply voltage sinusoid) to consumers connected via a UPS; Fully adjustable output voltage.
• pure sinusoidal output voltage;
• high efficiency;
• compatibility with diesel generators with a power reserve factor of no more than 1.3;
• maximum protection against surges, surges, surges and power outages;
• possibility of parallel connection of several UPSs;
• possibility of autonomous load support for 20 minutes;
• the possibility of uninterrupted switching of the load to power from an external power supply network through the built-in and external bypass;
• galvanic isolation of input and output circuits;
• remote monitoring and control of UPS parameters.

2.2. Solution structure

Depending on the power supply requirements of consumers, they are used different options construction of power supply circuits. Let's consider several options.

2.2.1. Using a guaranteed power supply scheme on site

If at a facility only a diesel generator set is used as a backup power source, then such a scheme is called a guaranteed power supply scheme, and consumers receiving power from the diesel generator set in the event of a loss of voltage from the main supply network are consumers of guaranteed power supply.

It is advisable to use such a scheme in cases of frequent loss of voltage from the main supply network and the absence of category I consumers of a special group at the facility, who need power supply for normal functioning without breaking the sinusoid of the supply voltage.

2.2.2. Using an uninterruptible power supply circuit on site

If a facility uses only an uninterruptible power supply as a backup power source, then such a circuit is called an uninterruptible power supply circuit, and consumers receiving power from the UPS in the event of a loss of voltage from the main supply network are uninterruptible power supply consumers.

It is advisable to use such a scheme in cases of infrequent and short-term loss of voltage from the main supply network and in the presence of category I consumers of a special group at the facility.

2.2.3. Combined use of uninterruptible and guaranteed power supply schemes at the facility

If a facility uses both a diesel generator set and an uninterruptible power supply as a backup power source, then such a scheme is called an increased reliability scheme using an uninterruptible and guaranteed power supply.

If the voltage of the main supply network disappears, the diesel generator set receives a command to start it. At the moment of starting the diesel generator set (5-10 sec.), consumers of guaranteed power supply are left without voltage for a short time. Power supply to consumers of guaranteed power supply is restored when the diesel generator set reaches the rated frequency and voltage.

During the startup of the diesel generator set, the UPS switches to batteries, and the uninterruptible power supply consumers are powered from the UPS batteries for as long as necessary to start the diesel generator set. Thus, power supply to uninterruptible power supply consumers is carried out without breaking the sinusoid of the supply voltage.

When the supply voltage of the external power network is restored when consumers are switched from the diesel generator set to the external power supply network, the consumers of the guaranteed power supply are left without voltage for a short time. Thus, consumers' food supply returns to normal. The diesel generator set, after a complete stop, goes into standby mode.

Power supply from the diesel generator set is possible for a period of time determined by the fuel reserve in the fuel tank of the diesel generator set and the specific fuel consumption (the value of this parameter depends on the load), as well as the possibility of refueling the diesel generator set during operation. If the power supply from the main input is not restored before the end of the fuel life in the standard fuel tank, the automatic control unit of the diesel generator set will stop the diesel generator.

It is advisable to use such a scheme for objects that require increased power supply reliability.

3. Creation of an uninterrupted and guaranteed power supply system at the site

3.1. Necessary conditions for creating a guaranteed power supply scheme at the facility

When creating a guaranteed power supply scheme at a facility, the following requirements must be taken into account:
• diesel generator sets must have a mean time between failures of at least 40,000 hours;
• operation of diesel generator sets with a capacity load of less than 50% for a long time is not recommended, and with a load of less than 30%, it leads to the supplier’s refusal to provide warranty obligations for the equipment;
• time for emergency start and load acceptance from standby mode in hot standby no more than 9 seconds.
• ensure the possibility of carrying out repair work and routine maintenance of the diesel generator set without disrupting the normal operation of the power supply system;
• provide remote control of diesel generator set operation;
• exclude the possibility of parallel operation of diesel generator sets with external system electricity supply;

3.2. Necessary conditions for creating an uninterruptible power supply circuit at the facility

• a single failure of any UPS element should not lead to a complete loss of system functionality;
• the average service life of the SBP is at least 10 years;
• avoiding overloads of neutral cables of input electrical networks and equipment of transformer substations;
• work for a long time in the mode of disconnecting the external power grid and providing power to critical consumers from the UPS;
• ensuring the possibility of carrying out repair work and routine maintenance of the UPS without disrupting the normal operation of the power supply system;
• providing remote control of operation and UPS;
• performing the correct completion of technological processes in the event of the disappearance of external power and the expiration of the battery autonomy life.

3.3. Necessary conditions for creating a combined uninterruptible and guaranteed power supply scheme at the facility

When creating an uninterruptible power supply circuit at a facility, the following requirements must be taken into account:
• UPS class - on-line, as the only one protecting the load from all existing problems in the electrical network;
• The UPS power is selected based on the load power;
• A UPS is required to be supplied rechargeable batteries. In general, the battery backup time is selected in the range of 5-10 minutes;
• to reduce nonlinear distortions of currents introduced by the UPS into the supply network, UPSs with rectifiers based on IGBTs are used - transistors with 12-pulse rectifiers or with active rectifiers;
• It is advisable to select a UPS with a system for smooth transition of the UPS to power from the battery to the network;
• the power of the diesel generator set and UPS is selected in the ratio: diesel generator set/UPS = 1.3;
• The diesel generator set must be equipped with an automatic output voltage regulator and an electronic speed controller for the drive motor.

As the experience of the Research Center shows, the choice of parts of the uninterruptible and guaranteed power supply system, taking into account the above requirements, ensures a consistent and stable working together UPS and DGS. Additional benefit This scheme is superior to the previous two - practically unlimited operating time in offline mode, i.e., complete independence of the power supply to the critical load (consumers of category I and consumers of category I of a special group) from problems in the main network.

4. Solution schemes

4.1. Guaranteed Power Supply Scheme

4.2. Uninterruptible power supply circuit

4.3. Uninterruptible and guaranteed power supply scheme

5. Manufacturers of equipment for the implementation of guaranteed and uninterruptible power supply schemes

5.1. General principles when choosing a manufacturer

When choosing a manufacturer to supply equipment for creating a guaranteed power supply system at sites, the NIC company relies on the following indicators:
• equipment compliance with Russian standards;
• quality assurance and operational reliability;
• acceptable delivery times;
• competent technical support from the manufacturer.

5.2. Manufacturers of diesel generator sets and uninterruptible power supplies

Having considerable experience in creating guaranteed power supply systems, our company gives preference to such manufacturers as: F.G. Wilson, Gesan, Cummins, SDMO.

When creating uninterruptible power supply systems at sites, our company most often uses APC UPSs; also, Powerware UPSs are used quite often, and less often - Libert.