Backup load switch. Four backup power schemes. Types and requirements for ATS

Nothing can be worse than blackouts in the winter. Any of the suburban residents sooner or later faces a situation when the lights go out, the well pump stops pumping water, and the heating system batteries cool down before our eyes. Time to use the backup power!

But there is another solution to the problem of power outages: the back-up power system at home, or PSA for short.

For the correct choice of such a power supply system, it is necessary to understand how it differs from an autonomous power supply system (SAP).

Andrey-AA, New Moscow.

PSA is used when connected to the main power grid. When the main power is turned off, the backup power supply "picks up" the main consumers of electricity: borehole pump, boiler, refrigerator, computer, TV and other electrical equipment.SAP is the main power supply system for the home, used in the complete absence of the main electrical network.

We turn to the choice of a backup power system. According to Andrey-AA, there are 4 main types of backup power for the home.

If the network is switched off for a short time, but for a total of more than 10 hours per month, then a system consisting of an inverter, a charger and a battery pack charged from the network will be optimal.

An inverter is a DC converter from batteries into an alternating single-phase voltage of 220V, from which the equipment in the house operates.

If the network is turned off for less than 10 hours a month, then a system of an electric generator with an internal combustion engine (ICE) equipped with an automatic start system is more profitable.
If the network is switched off frequently and for a long time, or when the mains voltage is too low, then a system consisting of a generator, a battery pack, a charger and an inverter is optimal.

Autonomous power supply systems are built on a similar principle, but they are subject to higher power requirements.

If the required power can be limited to 1-1.5 kW, then a car with an inverter connected to it can be used as a backup power system.

Let's take a closer look at the third option. User with nickname galaxy456 offers a step-by-step plan for creating a budget backup power system for the home.

1 Two cables from the utility room are brought into the electrical panel. The first cable is needed to supply electricity to the inverter. The second is to transfer electricity from the inverter to the house.

galaxy456

I have a small shield mounted on the street, in which an automatic reserve input scheme is implemented, or ATS for short.

AVR is an automatic switch of one load to two supply lines - main and reserve.

2 We put an inverter, batteries in the utility room and switch all devices.

There are two main types of inverters - with a sine output (the best option) and with the so-called "modified sine". If the inverter produces a “modified sine”, then some devices, when connected to it, may fail due to the high level of frequency harmonics in the power supply - 150Hz, 250Hz, 350Hz, etc.

In the event of a power outage, such a system works as follows. ATS independently and quickly - so that the devices do not have time to turn off, switches power from the main to the backup.

Now all connected energy consumers continue to work from batteries and the inverter. If there is no power supply for more than 5-6 hours, then, without waiting for the batteries to be completely discharged (this greatly reduces their service life), to continue uninterrupted power supply, you must manually start the generator.

There are backup power systems with automatic start of the generator, installed in a heated utility room and equipped with forced exhaust gases. The main disadvantage of such PSAs is their high price.

galaxy456

After starting the generator, the inverter transfers the load to power the devices from it and at the same time starts charging the batteries. Thus, the operating time of the system is extended and the motor resource of the generator is saved, because. it does not work continuously.

It must be remembered that the generator should be started after the battery capacity has been used up by about 30-60%.

Any, even the most advanced and expensive backup power system, first of all, teaches you to save energy in the house, because. the operating time of the backup power supply system at home directly depends on this.

Forum members advise:

Replace all the light bulbs in your home with energy efficient ones.
lay a second, backup power line, to which, in the event of a power outage, you can connect the most necessary equipment in the house;
how to insulate the house to reduce heating costs;
when the backup power system is operating, do not use powerful electrical appliances: iron, electric kettle, vacuum cleaner.

Andrey-AA

Turning on a hair dryer, kettle or iron for 3-7 minutes will not drain the batteries much, but it is better not to allow ironing or working with a powerful power tool.

To build a PSA, the load in the house can be divided into three parts:

Heating.
Water heating devices.
Devices that require mandatory backup power, namely:

lighting;
heating circulation pumps;
borehole pump and pumping station;
computer;
refrigerator, TV, Internet.

Also, a car can be used as a backup power system. For this you need:

Purchase an inverter with a sinusoidal output for 12-220 V with a power of up to 2 kW with protection against overcurrent or overpower.

Users of the FORUMHOUSE website can learn how to make a power system on their own. All information on the calculation is collected in this diary. Automatic "from A to Z" is described in this topic.

And this video shows how an inverter and battery pack can increase the electrical power in the house.

Quite often it becomes necessary to provide backup power to your device, this article discusses 4 ways to ensure this.

Simplest

The easiest way to switch to backup power is 2 diodes

Only one of the diodes will be open, from that power source, the voltage on which is greater. The advantages of the scheme are simplicity and low cost. The disadvantages of the circuit are obvious, the dependence of the voltage on the load on the current, the type of diode (Schottky or conventional), temperature. The voltage will always be lower than that of the source by the amount of voltage drop across the diode.

A little harder

This circuit is a little more complicated, it works like this: when the VCC voltage is present, and it is greater than the voltage of the backup source (in this case, it is the BT2 battery), then the mosfet is closed, because the voltage at the gate (Gate) is higher than at the Source (Source) , the voltage pass to the load and the Source is provided by the opened diode D3. When VCC disappears, the Gate voltage will disappear after it, but the diode inside the mosfet will open, providing voltage at the Source, and since there is now voltage at the source, but there is no voltage at the Gate, the transistor will fully open, ensuring switching of the battery without loss of voltage. This method is great for switching power for the GSM module, we select 4.5V external voltage, then 4.2-4.3V will come to the module through diode D3 and the voltage will go from the battery without loss.

Expensive but lossless

Without voltage loss, you can switch sources using special microchips, in particular LTC4412 download datasheet However, this microcircuit can be scarce and expensive.

Optimal Lossless

Well, here we come to the optimal method, and without loss. First, let's look at the block diagram of the LTC4412

It is immediately clear that there is nothing complicated in it, so why not repeat it on discrete elements? The PowerSorceSelector block is a matrix of two diodes that provides power to the rest of the circuit, A1 is a comparator, AnalogController is not clear, but it can be assumed that it does not do anything particularly important, it will become clear later why.

Let's try to picture it.

DA3 is a comparator. It compares the voltages of the two sources. Powered through diode D4 or D5. When the voltage at VCC is greater than the battery, the output of the comparator goes high, this closes VT2, and opens VT3, because it is connected to the output through the inverter. Thus, VCC passes to the load without loss. In the event that VCC is less than the battery, a low level at the output of the comparator will close VT3 and open VT2.

It is necessary to say a few words about the choice of details. DA3, DD1 must have a consumption that is acceptable in this system, the choice is very wide, from units of milliamps to hundreds of nanoamps (eg MCP6541UT-E / OT and 74LVC1G02). Diodes are necessarily Schottky, if the drop across the diode is higher than the transistor opening threshold (and for IRLML6402TR it can be -0.4V), then it will not be able to close completely.

It could only work when the voltage of the main source was lost; it could not protect the load from a decrease or increase in voltage. In the new version of the device, these shortcomings were corrected, namely:

The device will not transfer the load to the backup power source even if the main source voltage is reduced.

The device is not capable of operating at a voltage of less than 6 volts.

The device will not protect the load when the voltage rises above the permissible value.

The new version of the device has significantly improved characteristics.

Able to work with input voltage of the main source from 6 to 15 V.

Load protection against undervoltage or overvoltage. Two comparators are used to control the voltage of the main source. When the main voltage source is turned off, the operation of the device is similar to its previous version.

The current consumed by the load is limited only by the maximum current that the contacts of the applied electromagnetic relay can withstand.

The device is powered by a 12 V backup power source and consumes a current of about 100 mA, if the voltage of the main source is less than 12 volts, you need to use a stabilizer and turn it on in the gap shown in the diagram, and also set the protection thresholds with construction resistors.

Device operation

The voltage of the main source is supplied to the resistors R6 and R12 from which the voltage is supplied to the inputs of the comparators, where it is compared with the voltage coming from the stabilizer VR1. A separate stabilizer VR1 is used so that when the voltage value of the backup power source changes, the protection operation thresholds do not change. I will briefly describe what these tuning resistors are for. Resistor R12 is responsible for triggering the protection when the voltage drops below the minimum threshold that is set by this resistor. In my case, this threshold is 10.5 volts, and in order to set it, you need to set a voltage of 1.3v at pin 7 of the comparator with this resistor at an input voltage of 10.5 volts, which is lower than the comparator threshold, since the voltage on the 6th leg of the microcircuit is 1.65 volts, protection will work immediately. Resistor R6 is responsible for the operation of the protection in the event of a critical increase in the voltage of the main source. In my case, the maximum voltage value is set at 13 volts. At this voltage, resistor R6 must be set to 4 volts on the 5th leg of the microcircuit, which will trigger the protection and switch the load to a backup source. Thanks to these resistors, the protection is triggered when the voltage drops to 10.5 volts, or rises to 13.

The most interesting part of the circuit is the assembly assembled on DD1 and DD2 microcircuits. It is actually a protection scheme. Two inputs of this node are connected to comparators, but in order for the logic level 1 to appear on pin 8 of the DD1 chip and the protection to work, certain conditions must be created. This node is also interesting in that a logical unit at output 8 DD1.1 will appear if there are identical logical states at the inputs, either two 0s or two 1s. If one input is 1 and the other is 0, then the protection will not work.

The protection scheme works as follows. With a normal input voltage of the main source, only the DA1.2 comparator works, since the voltage is above the minimum shutdown threshold and, therefore, the open output transistor of the DA1.2 comparator closes terminals 4 and 5 of the DD2.4 element to ground, which is similar to the state of logical 0, and at the inputs 1 and 2 of the DD2.3 element, a voltage of about 4.5 - 5 volts operates, which is similar to the state of logic 1, since the voltage does not reach 13 volts and the DA1.1 comparator does not work. Under this condition, the protection will not work. When the voltage of the main source rises to 13 volts, the DA1.1 comparator starts working, the output transistor opens and by closing the inputs 1 and 2 of DD2.3 to ground it forcibly creates a logic 0 level, thereby forcing a logic 0 level to appear on both inputs and the protection is triggered. If the voltage has fallen below the minimum threshold, then the voltage supplied to the 7th leg of the comparator drops to a level below 1.65 volts, the output transistor will close and stop closing inputs 4 and 5 of the DD2.4 element to ground, which will lead to the establishment of voltage at inputs 4 and 5 4.5 - 5 volts (level 1). Since DA1.1 is no longer working and DA1.2 has stopped, a condition is created under which the level of a logical unit will appear at both inputs of the protection node and it will work. The node operation is shown in more detail in the table. The table shows the logical states on all the outputs of the microcircuits.

Table of logical states of node elements.

Setting up the device

A properly assembled device requires minimal adjustment, namely the setting of protection thresholds. To do this, instead of the main voltage source, connect an adjustable power supply to the device and use trimmer resistors to set the protection operation thresholds.

Appearance of the device

The location of the parts on the device board.

List of radio elements

Designation	Type	Denomination	Quantity	My notepad
DD1, DD2	Logic IC	K155LA3	2	To notepad
DA1	Comparator	LM339-N	1	To notepad
VR1, VR2	Linear Regulator	LM7805	2	To notepad
VT1	bipolar transistor	KT819A	1	To notepad
Rel 1	Relay	RTE24012	1	To notepad
R1	Resistor	3.3 kOhm	1	To notepad
R2, R3	Resistor	1 kOhm	2

A power failure creates not only discomfort, but can lead to significant material damage and a threat to the safety of people. Uninterrupted power is provided by two sources of electricity, one of which is usually the power grid, and the other is the battery, diesel generator, and others.

Reserve connection board with two independent inputs

Power continuity can be created by supplying power from two sources at once. The method has the following disadvantages:

higher short circuit current;
increased power losses;
complicating the security system.

Automatic transfer of the reserve (ATS) allows you to quickly restore the supply of electricity by switching on a switching device that separates the supply lines. The real response time is tens of seconds, but can reach 0.3 sec. In this case, it is necessary to take into account the power of the additional power supply so that it can cope with the connection of the consumer system. If this cannot be achieved, the protection scheme is organized in such a way that only the most important loads are connected.

The photo above shows an ATS shield with two independent inputs.

Types and requirements for ATS

There are 2 types of ATS switch:

one-way - one of the power lines is working, and the other is a backup;
two-way - any input can be working or reserve.

From the ATS, high speed and mandatory inclusion are required, regardless of the reasons for which the voltage has disappeared.

Automatic switching on of the reserve occurs by a signal from a sensor, for example, an undervoltage relay. The power supply at the inputs and the phase sequence are controlled.

The requirements for AVR are:

The absence of a short circuit in the controlled area.
AVR serves to connect the reserve whenever the voltage at the input to the consumer disappears. An exception is a short circuit, in which the ATS is blocked.
Single actuation. The switch cannot be switched on more than once until the short circuit is removed.
The ability to adjust the voltage response threshold to reduce the effect of its drawdowns during start-ups of load motors.
The switch will only operate if voltage is present on the standby section.

If the above conditions are met, the ATS logic system issues a command to turn off the input switch and turn on the section switch. In this case, an electrical blocking of their simultaneous activation is carried out. Some ATS models are also equipped with a mechanical interlock.

AVR operation with a generator

Electricity supply companies divide consumers into three categories according to the degree of reliability of electricity supply. Private houses and apartments belong to the third - the lowest category. In apartments, uninterruptible power supplies on batteries are usually used.

For a private house, a gasoline or diesel generator can also be a backup power source. If before they were put into operation manually, now automatic start is possible. It all depends on what price you pay for it.

For automatic redundancy, it is preferable to use a device with microprocessor control. Easy programmable relay controllers are widely used in everyday life and production. The relay input receives signals from voltage sensors. When the power is turned off, the controller starts the generator engine. After reaching the nominal parameters, which takes a certain time, the ATS circuit switches the load to backup power. In this case, there are time delays with the connection. For domestic needs, they are acceptable, but for powerful and responsible loads, the task becomes more difficult.

The figure shows a diagram of an uninterruptible power supply using an additional diesel generator.

Scheme of connecting a standby diesel generator to the load

A network and a generator are connected to the input of the ATS, and the output is connected to the load. The main power source is usually the mains. When the mains voltage is turned off, the generator starts, after which the AVR connects the load to it. As soon as the power supply is restored, the power is switched to the previous mode, and the generator will turn off after a specified time. The figure below shows the electrical circuit of an uninterruptible power supply.

Performing ATS on contactors

The scheme is used for a single-phase network of a private house or a small industrial building.

ATS scheme on one contactor for a single-phase network

To put the circuit into operation, automata SF1 and SF2 are switched on. Power is supplied to the contactor KM1 - the switch of the main and backup input. When it is triggered, contact KM1.1 connects the circuit of the main power source, and the backup circuit is opened by contact KM1.2.

The two-pole switch QF1 is turned on, the contacts of which close the circuit of the main power source.

In the event of an emergency, when the main input is de-energized, the contactor KM1 is turned off and the main network is turned off and the reserve is connected by a normally closed contact KM1.2. When the power supply to the main input is restored, the loads are switched to it again using the contactor.

If you need to manually connect the reserve, it is enough to turn off the circuit breaker SF1.

It is necessary to take into account the power of the backup source. Usually, the most necessary loads, such as lighting and heating, are powered from it.

Phase and neutral switching (contacts KM1.1 and KM 1.2 in the figure below) at the same time makes it possible to completely exclude the idle input from operation and use an autonomous reserve.

ATS scheme on one contactor with phase and zero disconnection

The inclusion of the ATS in operation is carried out as in the previous scheme, only the KM1 switch breaks or connects the phase and zero. The scheme is most common for connecting an autonomous voltage source, for example, an uninterruptible power supply or a diesel generator. It shows in detail the connection of loads through two-pole circuit breakers QF2, QF3, QF4, and also shows the ground wire PE, which is not connected to the power supply of the loads. It is connected to the housings of electrical appliances and performs the function of protection against electric shock.

The figure shows a typical connection diagram of the АВР-3/3 module for three-phase supply and reserve circuits.

Typical wiring diagram for AVR-3/3 module

Phases on the module are marked L1, L2, L3, neutral - N. Switching contacts of built-in relays are connected to terminals 11, 12, 14. The device is controlled by a microprocessor that controls the voltage through two three-phase lines.

Video about the introduction of the reserve

How to assemble an ATS unit for a generator can be found in this video.

Interruptions in the supply of electricity can be the cause of various negative phenomena for consumers. The ATS device allows you to maintain the operability of objects for which a constant supply of supply voltage is essential.

Hello to all readers. Today we have another piece of iron in the review. Yes, it's not a voltage regulator. I'm probably already tired of stabilizers. But this device is still related to nutrition, and is quite important. And we will prepare the PRP-1 backup power switch. It is produced by ATS-CONVERS LLC, Pskov. I had an RBS 3K-220V module from the same company in the review, but it didn’t suit me, from the word at all. You can also read about it on my blog. The wrong choice occurred due to the fact that there was no documentation on the manufacturer's website. I'll take a break. Previously, this company had such a not-so-very website, and it did not have any documentation or all the necessary information. But now ATS-CONVERS LLC has a new website where you can find everything you need for their products. Well done for updating. Below is a screenshot of the page from the site, where information about the module is located.

In the life of any server room and in the practice of any system administrator, a crutch appears called "one power supply unit per device." For a long time I bothered with the search for such modules, and found. I repeat, this is a different module, but its essence is the same for me. It often happens that two good powerful UPSs are installed in the server room (of course, everything depends on the budget of the organization), and devices are connected to these UPSs. Most modern servers and switches have two power supplies. We just connect one PSU from the device to different UPSs. This will ensure the fault tolerance of the system and will always allow you to service the same UPSs without disturbing the system's performance. Agree conveniently. But what if there is only one power supply in the receiver device???!!! This wonderful PRP-1 module will help us with this. Many may argue why not use any phase switches, or similar devices. The answer seems to be simple. These devices are used to switch the load at the input, and we switch the load at the output, and this must be done quickly so that there is no long-term network interruption. This does not mean that you can break the network for a second, we are talking about milliseconds of break. Enough demagoguery, let's get to the point. Let's start as usual with the characteristics. Even on the manufacturer's website I noticed such a thing that the design looks like in my articles. The parameter is written in plain text, and the value is highlighted in bold. Actually it's convenient. Do not forget that the characteristics of the device can be changed by the manufacturer at any time. Therefore, just in case, look at the specifications on the official website of the manufacturer https://www.atsconvers.ru/catalog/product/95/

Input parameters:
Number of inputs, pcs: 3
Rated input voltage, V: 220 (230 )
Rated input voltage frequency, Hz: 50
Input AC voltage shape: arbitrary
Input voltage phase difference: arbitrary
Limit voltage range, V: 175 – 390
Adjustment range of output switching settings at increase/decrease of input voltage, V: 176 – 269
Adjustment range of output switching settings at increase/decrease of input voltage frequency, Hz: 43 – 59
Power consumption at input voltage, VA: no more than 10

Output parameters:
Voltage range (within the range of switching settings), V: 176 – 269
Rated output current, A: 16
Rated output power, VA / W: 3500 / 3500
Load power factor: 0,5 – 1
Load current crest factor, not more than: 3,5
Overload during the normalized time interval,%: no more than 120 - 2 min, 150 - 5 s, 175 - 2 s, 230 - 1 s, 400 - 0.05 s
Switching time, ms: 4 – 6
Efficiency at rated load: not less than 0.99

Means of remote control and management:
Isolated RS-232
Connecting to the RS-232 port of a PC
Software for remote control and management of Power Agent TS
Relay interface dry contacts
Connecting to a PC via a discrete input / output board
Web/SNMP adapter type WEBtel (optional)
Control and management in Internet/Intranet networks
Power Net Agent SNMP monitoring system (optional)
Control and management of PRP and other equipment on the Internet

Compliance:
Safety GOST R IEC 60950 class I
Noise emission and noise immunity GOST R 50745 class B

Working conditions:
Working mode: Continuous
Working ambient temperature, 0 С: from + 1 to + 40
Cooling: natural
Degree of protection: according to GOST 14254 IP20
Execution according to the influence of external mechanical factors: according to GOST 17516.1 M1

Dimensions and weight:
Overall dimensions (HxWxD), mm: 44(1U)x483x245
Weight, kg: 4.5

Let's start unpacking. Oh yes, I almost forgot. The module was bought for me at work. I really need him. I will take another one. In general, this module comes in a wooden box, such as they used to send parcels by mail. But she didn't get me. The intermediary organization did not deliver it to me. But we agreed on this point. The module itself is in a dense plastic bag, which is also tightly packed. Very positive. Separately, there is a package with a delivery set. Looks something like this:

The front panel of the device is quite idle. It has an LED panel that indicates which line the current flows through, and which one is in reserve, or perhaps the bypass is turned on at all. In the middle there is a sticker warning about turning the handle and disconnecting the load. To the right of the center there is a switch that has three positions: input 1 and 2, input 3 and off. The "off" position - completely disconnects the load at the output. Next comes the RS-232 port for connecting to a computer. And already almost near the "Ear" there is a bolt for connecting the ground. In general, grounding is connected by default from the input power connectors, but at the request of GOST, a bolted ground connection must be. Who cares about such a connection - he will connect. In my case, the ground coming from the input connectors is enough.

The body of the device is made of thick sheet metal, painted black with powder enamel. The device itself is heavy. But not only because of the thickness of the case. Mounting "Ears" for the rack are also made of thick metal, and are attached to the case with three screws. From the outside, everything looks very positive.

And we smoothly move on to the back of the PRP-1. From left to right: DUZ connector (AS/400); three circuit breakers, one for each input; output connector IEC60320 C19, with a maximum current of 16A; three input connectors type IEC 60320 C20, with a maximum current of 16A.

Well, let's open the device. There are no seals on it, and they do not give anything. Intervention in the scheme can be seen almost always. The device really surprised me with the build quality. All wires are crimped where necessary and also bundled. Nothing is chattering. This module made me happy. But here I want to express my slight indignation about the grounding cable inside the device. As far as I know, grounding is by no means connected by a loop. Here are three input connectors that are connected by a cable - then it's okay, but the fact that the output connector is connected by a cable is not true. It must be connected by a separate cable to a common ground node in the device.

The same mechanical input switch on the front panel:

The main board is closer. Later I will pull it out of the case, and it turns out that not only the massive case gives weight to the device, but also the main board, on which four low-profile transformers are installed. Two of them are represented by the brand and the other two by the smaller brand.

The board has four relays, the model of which is also from Song Chuan Precision. The relays are designed for a current of 16A, which is generally without a margin. But I don't know how this module switches. Perhaps at the moment of switching, there is no current on the relay contacts, as is done in a voltage stabilizer. There will be a kind of mystery, or the developer himself will explain.

display board. Didn't unscrew completely. It makes no sense. It looks like this from the inside:

Capacitors from different companies are installed on the board. There are also some SAMWHA and Hitano. I don't know if I can be trusted or not.

A field effect transistor was found on the board. That's just what function it performs - there was no time to figure it out. On the Internet there is a datasheet for Vishay, but this transistor is definitely not Vishay. Looks more like Chinese. In general, it is not known who the manufacturer is.

The microcontroller from Microchip Technology is used as the “brains” on the board. There are a sufficient number of other microcircuits around the MK. Of these, from Microchip Technology, is a timer-calendar chip. Next to it is a microcircuit - this is non-volatile memory. Nearby are two optocouplers and, it seems, also of Chinese origin. Yes, it doesn't really matter. The main thing works. I also often use Chinese parts. We continue. On the board we see an integral stabilizer from STMicroelectronics. A chip from the same STMicroelectronics is installed next to it. This chip is an assembly of seven Darlington transistors.

There is one interesting point on the board. The inductor is soldered to the board not just as it is usually done, but by means of another small scarf. It turns out such a scarf in the board. It is interesting for what reasons it is made.

As I said, I unscrewed the board from the case. The screws are screwed from the heart. In order for a crack to appear, or some kind of defect from mechanical stress or skew of the case, you need to try very hard. The board is attached very well. Installed accordingly on the racks, so as not to touch the case. There are no substrates for the board, and in general it is not needed. In the corner of the board there is an inscription who is the manufacturer, year and KSD.

Due to the fact that the device is smart, a current sensor is also installed on the board in order to avoid overloading the device and the resulting problems.

Mounting inside the PRP-1 module is carried out with the Prysmian PuGV cable, from the Russian manufacturer LLC REK. I used a PVA cable of different sections from this company and, in general, I am satisfied and have nothing against it. Good cable. Although a few years ago, a lot of people complained about him. But now OK.

the same three circuit breakers

The board has a fairly large number of unsoldered seats, including those for microcircuits. I wonder what they are used for.

And this is the inside of the DUZ connector.

I don’t know how it happened, but my equipment went to the end. There is nothing special to see here. The kit includes connectors for connecting the device. I have factory cables C20-C19 for connecting to the UPS, but I don’t have an outlet block with a connector like the one at the output. But it is included in the package. I disassembled one of the forks, and everything is very good. The metal is thick, the clamp is made under the screw. Connectors, what you need.

conclusions

The PRP-1 backup power switch is the device I was looking for. It does not depend on which phases or to which UPS the inputs are connected. This device has completely isolated and independent inputs. Switching from the supply line to the standby line is fast. The documentation says that 4-6 ms, but I would say by eye that it’s still about 10 ms. The only drawback of the device is one output connector. It won't be enough. Ideally, of course, there would be two output connectors, or one more additional IEC 60320 C13 (F) female connector. Although his current is 10 A, the load does not have to be large. As for the exit, the restriction immediately works here. You need to either immediately take a large block of sockets with such a connector, or take a large pilot with a C14 connector, cut it off, and connect the plug that comes with the kit. But here again a crutch, the wire should not be thin. It turns out such a vicious circle. You can, of course, include an outlet block in an outlet block, but I don’t practice such loops and I’m afraid of them.

I have only positive impressions about this device. Recommend for purchase. Stable all network and trouble-free operation. I have it all. Thanks to all.

ATTENTION! With pleasure I will accept for testing a voltage regulator of any brand, model and power.