Purpose, principle of operation, scope. The protective disconnection is called Automatic shutdown of electrical installations with single-phase (single-pole) touch to parts under voltage, invalid for humans, and (or) when the leakage current occurs in the electrical installation of the leakage current (closure) exceeding the specified values.

Assigning a protective disconnection - Ensuring electrical safety, which is achieved by limiting the exposure time of hazardous current per person. Protection is carried out by a special protective shutdown device (UZO), which operating in standby mode, constantly monitors human damage conditions.

Scope: electrical installations in networks with any voltage and any neutral mode.

The largest propagation of the protective shutdown was obtained in electrical installations used in networks of voltage up to 1 kV with grounded or isolated neutral.

The principle of operation of the UzO is that it constantly controls the input signal and compares it with a predetermined value (charter). If the input signal exceeds the setpoint, the device is triggered and disables the protected electrical installation from the network. The input signals of the protective disconnection devices use various parameters of electrical networks that carry information about the conditions of human damage to electric shock.

The entire outer view of the input signal is classified into several types (Fig. 4.11).

In addition, the UDO can be classified according to other criteria, for example, according to constructive execution.

The main elements of any protective shutdown device are the sensor, converter and executive body.

The main parameters for which this or that Uzo is selected are: Rated load current ie The operating current of the electrical installation, which flows through normally closed contacts of the UDO in the standby mode; Rated voltage; setpoint; Device operation time.

When closed on the body, protective grounding

In fact, this type of Uzo duplicates the protective properties of grounding or reassembly and is used as an additional protection, increasing the reliability of grounding or reassembly.

This type of UzO can be applied in networks with any neutral mode when grounding or non-efficient.

The RCD is reacting to the differential (residual) current, are widely used in all industries. The characteristic feature is multifunctionality. Such UZOs can protect a person from electric shock with a direct touch, with an indirect touch, with an asymmetrical decrease in the insulation of the wires relative to the Earth in the device's protection zone, during the grounds for Earth and in other situations.

The principle of the operation of the Uzo of the differential type is that it constantly controls the differential current and compares it with the setpoint. Upon exceeding the value of the differential current setpoint, the UDO triggers and turns off the power consumer of the electricity from the network. The input signal for three-phase UzO is the zero sequence current. The input signal of the UDO is functionally connected to the current flowing through the human body.

The scope of the RCD of the differential type - network with a grounded neutral voltage to 1 kV (system TN - S).

The inclusion scheme of the RCMO responding to the differential current in the network with a grounded neutral type

The sensor of such a device is the zero sequence current transformer (TNTP), on the output windings of which a signal is formed, proportional to the current through the human bodyI. H. . The UDO (P) converter compares the input signal value with the setpoint, the value of which is determined by the permissible current through a person, enhances the input signal to the level necessary to manage the executive body (IO). The executive body, for example, contactor, turns off the electrical installation from the network in the event of a danger of electric shock in the RCO protection zone.

Protective shutdown - High-speed protection, providing automatic shutdown of electrical installation (after 0.05-0.2 C), when there is a danger of human damage to electric shock.

The protective function of the protective shutdown devices (RED) is the limitation of non-current passing through a person, but the time of its flowing gas, so that the conditions of the GOST 12.1.038-82 have solved. System of labor safety standards. Electrical safety. Maximum allowable values \u200b\u200bof tact and current voltages (approved by the Decree of the USSR State Standard of 06/30/1982 No. 2987).

According to this GOST, for example, at a current passing through a person equal to 500 mA, its exposure time should not exceed 0.1 s, at 250 mA - 0.2 s, at 165 mA - 0.3 s, at 100 mA - 0.5 s, etc. Scope of the UZO is very wide (electrical installation of public and residential buildings, administrative and industrial premises, workshops, gas stations (gas station), hangars, garages, warehouses, etc.).

The principle of the operation of the UZO is based on the change in any electrical values \u200b\u200boccurring during the circuit of the phase on the body, reduce the insulation resistance of the network below a certain limit with the direct touch of the person to the current parts of the electrical installation and in other cases dangerous to which the executive body responds To trigger a protective shutdown.

The most common and perfect is the Uzo-D, which reacts to the leakage current (differential current). Such UzOs consist of three functional elements: sensor, executive body and switching (disconnecting) device. The sensor captures leakage currents flowing from phase wires to the ground in the event of a person's touch to parts under voltage. The leakage current signal enters the executive body, where it is amplified and converted to the command to disable the switching device. The executive body of the UZO can be electronic or electromechanical (with a magnetoelectric latch). The second option is more reliable.

In fig. 24.13 shows the circuit of the Uzo-D (RCD with differential protection). The most important functional block of the RCD is a differential current transformer with a ring magnetic wire 1. In the absence of leakage current, i.e. Current passing through person, working currents in direct (phase) and reverse (zero working) wires will be equal and put in the differential current transformer 1 With annular magnetic core, but oppositely directed flows. In this case, the resulting magnetic flux is zero and there is no current in the secondary winding, the RCO does not work. When the leakage current appears (for example, when a person touching the electrical installation case, on which the insulation breakdown occurred and the voltage appeared) the current in the direct wire will exceed the reverse current to the leakage current (the leakage current in the figure is shown by a dot line). The inequality of the current causes nonbalance of magnetic flows, resulting in a differential transformer in the magnetic circuit 1 there is a magnetic flux, and in its secondary winding - differential current. This current comes to the starting authority 2, And if its value exceeds the threshold (specified) value, then it works and affects the actuator 3 Which due to its spring drive, the trigger and the contact groups opens the electrical network. As a result, the protected RCO electrical installation is de-energized. For periodic control of the health of the RCO press the button T. (test), an artificial differential (difference) current is created. The triggering of the UZO means that it is generally properly.

It should be noted that from all known electric power facilities of the UZO-D - the only, providing human protection against electric shock when directly touched into the current-carrying parts. In addition, it protects electrical installations from the fires, the root cause of which are current leaks caused by damage to the insulation faulty electrical wiring. Therefore, the UZO is also called "fire guard".

The protective shutdown device is characterized by the nominal operating current of the plug-in load (16, 25, 40 A), a nominal differential disconnecting current (10, 30 or 100 mA), speed (20-30 ms) and other parameters.

According to paragraph 1.7.80, PUE does not allow the use of UMOs reacting to the differential current in four-wire three-phase circuits (system TN-C). But if necessary, the use of the RCD to protect individual electrical receivers receiving power from the system TN-C, protective Re The conductor of the electrical receipt must be connected to Pen. -Ronor chain, feeding the electrical receiving, to the protective and switching unit (UZO).

Fig. 24.13.

It should be noted that in systems TN-C. (without a separate protective conductor), in ungrounded electrical receivers, isolated from the ground (for example, a refrigerator or washing machine on an insulating base), the UDO, included in the supply circuit of this electrical receiving, will not work, because there is no chain of leakage current, i.e. There will be no difference (differential) current. At the same time, a dangerous potential relative to the Earth is formed on the electrical installation case.

But if a person is touched by the electrical receiving housing and the current flowing through it will be larger than the disconnecting differential current of the UDO (setpoint current),

Uzo will work and turn off the electrical acceptor from the network. Human life will be saved. About TSYUD follows that the use of UZO in TN-C networks is still justified.

Windows Anti-Virus Windows Defender does not require individual actions to turn it off when installing an override antivirus system. The automatic shutdown is not at all 100% of cases, but most of them. As automatically disconnected, the protector itself and turns on when a third-party antivirus is deleted from Windows. But there are cases when the system needs to be intentionally left without antivirus - and without a third-party, and without regular. For example, temporarily to make certain settings into the system or installed software. There are also such cases that the protection of the PC needs to be abandoned completely. If the computer is not connected to the Internet, it makes no sense to spend its resources to work the antivirus. How to disable Windows Defender temporarily and completely? In this we will understand below.

1. Disable the defender in Windows 7 and 8.1 systems

In Windows 7 and 8.1, get rid of standard anti-virus protection easier than in the current version of the system 10. All actions are performed in the defender application window.

In Windows 7, you need to press "programs" in the defender window, then select "Parameters".

To disable the defender for a while in the parameters section, disclose the vertical tab "Real Time" tab and remove a tick with a real-time protection option. Click "Save" at the bottom of the window.

To disable Windows Defenders, in the Administrator tab, remove the check mark near the inscription "Use this program". Click "Save".

Approximately the same actions must be carried out in Windows 8.1. In the horizontal tab of the "Parameters" defender, we turn off real-time protection and save the changes made.

And to disable the standard antivirus completely in the vertical tab, the Administrator is removed from the inscription "Enable Appendix". We save changes.

After disconnecting the defender, a notification will appear on the screen.

You can turn on the protector back using the appropriate links in the support center (in the system tray).

Alternative option - Enable the defender in the control panel. In the "System and Security" section, in the Support Center subsection, you must press two "Enable Now" buttons as indicated in the screenshot.

2. Disable real-time protection in the Windows 10 system

In the current version of Windows 10, real-time protection is removed only for a while. After 15 minutes, such protection turns on automatically. In the defender window, click "Parameters".

We will fall into the "Parameters" application section, where the defender settings are held. Among them - a switch of real-time protection activity.

3. Full shutdown of the defender in Windows 10

A complete shutdown of Windows Defender in version 10 of the system is carried out in the Local Group Policy Editor. In the "Run" command or intrasystem search command, we enter:

Next, in the left window, we reveal the tree structure "computer configuration": first "administrative templates", then "Windows components", then - "Endpoint Protection". Go to the right side of the window and double click open the "Disable Endpoint Protection" parameter.

In the opened parameter window, set the position "Included". And apply the changes made.

After that, as in the case of Windows 7 and 8.1 systems, you will see a message that the defender is disabled. The way it is turned on the reverse - for the "Disable EndPoint Protection" parameter, you must set the "Disabled" position and apply the tincture.

4. Win Utility WIN UPDATES DISABLER

Win Utility Win Updates Disabler is one of the numerous tools in the software market to solve the issue with. In addition to the main task, the utility also offers some accompanying functionality, in particular, disabling the Windows defender completely into a couple of clicks. Win Updates Disabler itself makes the necessary changes in the Group Policy Editor. The utility is simple, free, supports a Russian-speaking interface. With it, it is possible to disable the defender in Windows 7, 8.1 and 10 systems. To do this, you need to remove ticks from options that are not interested, and only the point of turning off the defender. Next, click the "Apply Now" button.

After that you need to restart the computer.

To enable a regular antivirus, in the utility window, you must again remove checkboxes from unnecessary options and, by going to the second tab, activate the turn on the defender. As with the disconnection, then we click "apply now" and agree to the reboot.

Excellent day!

Why use protective shutdown?

The danger of lesion to the current is due to the tension of the touch (£ / milksha1, c) and then the power of the current, which can pass through the human body (/ "a). As is known.

where /? A - human body resistance, Ohm.

If the tension voltage at the time of the human touch to the housing or phase of the network exceeds the permissible value, then the actual threat of lesion and the degree of protection in this case can only be the rupture of the current circuit, disabling the corresponding area of \u200b\u200bthe network. To perform this task use a protective shutdown.

The protective disconnection is the high-speed protection, which provides automatic shutdown of the electrical installation when the danger of human damage is occurred.

Grounding and rewarding do not always guarantee people's safety. Protective shutdown. Significantly faster reassembly disables the damaged area of \u200b\u200bthe installation, the more guaranteed protects people from electric shock.

In what cases use protective shutdown?

Protective shutdown is used only in electrical installations with voltage up to 1000 as an independent protection or simultaneously with grounding:

in mobile electrical installations with an isolated generator neutral;

in stationary installations with an isolated neutral to protect working with manual power tools;

in stationary electrical installations with a deaf-marketed neutral on individual remote from transformers to high-power consumers, on which the protection is ineffective;

in the conditions of increased danger of electric shock. The scope of application of protective shutdown devices is practically not limited. They can be used in networks of any destination and with any neutral regime. However, they received the greatest distribution within up to 1000 V, especially where it is difficult to carry out an effective grounding or a downstream when there is a high probability of random touch to the current parts (mobile electrical installations, manual power tools).

What requirements are presented to a protective shutdown and what functions does it perform?

Protective shutdown can be used as the main type of protection or with grounding and reusing.

The protective disconnection device put the following requirements: self-control, reliability, high sensitivity and low shutdown time.

Protective shutdown separately or together with other means of protection performs the following functions:

protection when closing to the Earth or equipment case;

protection when hazardous leakage currents appear;

protection in the transition of higher voltage to the side of the lowest;

automatic control of the circle of protective grounding and reassembly.

How is the protective shutdown?

Protective shutdown is performed by very sensitive and high-speed protective arising devices. Sensitivity and speedy action Their significantly exceeds circuit breakers or other measures elements.

In electrical circuits of protective disconnecting devices, sensitive elements react to the appearance of current in the zero wire, voltage on the body of damaged electrical equipment, etc.

Protective disconnecting devices are triggered by 0.1-0.05 s, while the reinforcement is 0.2 or more. With such a short-term duration of the current through the human body, there will be a secure current even the value of 500-600 mA. Considering that the resistance of the human body is 1000 ohms, the current of the given value can flow through the human body only when its voltage is 500-650 V, and such a voltage in electrical networks voltage 380/220 V with a grounded neutral can not be Even with emergency mode in emergency situations.

Protective shutdown is also used in cases where the grounding device will cause significant difficulties (rock soils) or it is inappropriate due to the moving front of the work.

Therefore, protective disconnecting devices is a reliable protection of people from electric shock.

One of the security measures in electrical installations is the use of small stresses of about 36,34,12 V and less: for lamps of local lighting from machines; for portable lamps (12 V); Nutritional power plants, electric drills and other electrical tools.

Protective shutdown is performed in addition or in return to ground.

Shutdown is carried out by automata. Protective shutdown is recommended in cases where security cannot be provided by the grounding device or when it is difficult to perform.

Protective shutdown provides fast - no more than 0.2 with automatic shutdown of the installation from the supply network when the danger of lesion is occurring. Such a danger may occur when the phase is closed on the body of electrical equipment, with a decrease in the insulation of the phases relative to the Earth (damage to the insulation, closing the phase to the Earth); When a higher voltage appears in the network, with a random touch of a person to the current-carrying elements under voltage.

The advantages of the protective shutdown are: the possibility of its use in electrical installations of any voltage and at any neutral mode, triggering at low voltages on the housing - 20-40 V and the speed of shutdown, equal to 0.1 - 0.2 s.

The protective shutdown is carried out by means of switches or contactors equipped with a special disconnect relay. There are many different types of protective-disconnecting devices. The diagram of one of them is shown in Fig. 76. The protective shutdown switch consists of an electromagnetic coil, the core of which in the usual position holds the switch or special automatic on the network. An electromagnetic coil with one output is attached to the housing of the protected electrical installation, and the other to the earthing. When the voltage electrical installation was reached on the housing, over 24-40 V through the electromagnet coil passes the current, as a result of which the core is drawn into the coil and the switch under the action of the spring turns off the current, removing the voltage from the protected installation.

The use of the UZO in electrical installations of residential, public, administrative and household buildings can be considered only in the case of powering electrical applications from the network 380/220 with the grounding system TN-S or TN-C-S.

The UZO is an additional means of protecting a person from electric shock. In addition, they protect against fire and fires arising from possible damage to isolation, electrical wiring and electrical equipment faults. When the zero insulation level is violated, directly touching one of the current-carrying parts or when the protective conductors of the RCDO is almost the only high-speed means of human protection against electric shock.

The principle of operation of the RCD is based on the operation of a differential current transformer.

The total magnetic flux in the core is proportional to the difference in currents in the conductors that are primary windings of the current transformer. Under the action of EDC in the secondary winding circuit flows the current, proportional difference in the primary currents. This current and activates the starting mechanism.

In a normal operating mode, the resulting magnetic flow is zero, the current in the secondary winding of the differential transformer is also zero.

Functionally the Uzo can be defined as a high-speed protective switch that responds to the difference in currents in conductors supplying electricity. If in a nutshell to describe the principle of operation of the device, then it compares the current that has gone into the apartment, with a current that returned from the apartment. If these currents turn out to be different, the RCO instantly disables the voltage. This will help avoid harm to humans in cases of damage to the insulation of the wires, with careless handling of electrical wiring or electrical appliances.

Therefore, such a technical solution was born as a ferromagnetic core with three windings: - "Tokopodovaya", "Clake-in", "controlling".

The current corresponding to the phase voltage supplied to the load, and the current, extinguishing from the load in the neutral conductor, is supplied in the core magnetic streams of opposite characters. If there are no leaks in the load and the protective section of the wiring, the total flow will be zero. Otherwise (touch, insulation damage, etc.), the sum of two threads becomes different from zero. The stream occurs in the core leads to electromotive power in the control winding. The relay is connected to the winding of the control through the precision filtering device of all sorts of interference. Under the influence of the emerging in the winding of the management of the EMF relay breaks the phase and zero chains.

There are two main categories of UzO:

• 1) electronic
• 2) Electromechanical

Electromechanical UzOs consist of the following main functional blocks.

A differential current transformer is used as the current sensor.

The threshold element made on a sensitive magnetoelectric relay.

Actuating mechanism.

Testing chain, artificially creating differential current, to control the serviceability of the device.

In most countries of the world, the electromechanical RCOs were distributed. This type of Uzo will work in case of detection of leakage current at any voltage level in the network. Network voltage does not affect the current formation, the level of which is determining when determining the moment of operation of the magnetoelectric element.

When using a functional (serviceable) electromechanical Uzo is guaranteed in 100% cases, the relay is triggered and, accordingly, turn off the power supply to the consumer.

In the electronic UzO, the functions of the threshold element and, partly, the actuator performs an electronic circuit.

Electronic Uzo is based on the same scheme as electromechanical. The difference lies in the fact that the place of the sensitive magnetoelectric element occupies the comparison element (comparator, stabilong). To operate such a scheme, you will need a rectifier, a small filter. Because The zero sequence current transformer is lowering (ten times), then a signal amplification chain is also needed, which also will also enhance the interference (or the henbalance signal present at zero leakage). It is obvious that the moment of the relay is triggered, in this type of RCD, is determined not only by the leakage current, but also with a network voltage.

Rating forward It should be noted that the cost of electronic RCOs below electromechanical approximately 10 times.

In European countries, the overwhelming majority of Uzo - electromechanical.

Advantages of electromechanical RCOs are their complete independence from fluctuations and even the presence of voltage in the network. This is especially important because in electrical networks there is an opening of the zero wire, as a result of which the danger of electric shock increases.

The use of electronic RCOs is appropriate when the safety policy is needed for safety purposes, for example, in particularly dangerous, wet rooms. In some countries, the UZO has already built in the forks of electrical appliances, this is determined by the rules requirements.

To select a UZO with sufficient accuracy, you must consider two parameters:

• 1) rated current
• 2) leakage current (trigger current).

The rated current is the maximum current that will flow according to your phase wire. Find the value of the current is easy, knowing the maximum power consumed. It is necessary to divide the power for the worst case (maximum power with minimal COS (C)) on the phase voltage. It does not make sense to put the circuit on the current more than the rated current of the automaton standing in front of the RED. Ideally, with a margin, we take the RCD on the rated current equal to the rated current of the automaton.

There are UZOs with rated currents 10,16,25.40 (a).

The leakage current (trigger current) is usually 10mA or 30mA if the Uzo is set to the apartment / house to protect the human life, and 100-300m on the enterprise to prevent fires, when burning wires. (PUE 7th edition of P.P. 1.7.50 requires additional protection against direct touch in electrical installations to 1 kV to use the RCD with a nominal disconnecting differential current of no more than 30 mA.).

In addition to the Uzo, installed on the camshaft, you can meet the electrical outlet with the built-in UzO. These devices are two types: the first is set to the place of the existing socket, the second is connected to the existing outlet, and then the plug from the electrical appliance is turned into it.

The advantages of these devices include the lack of the need to replace the electrical wiring in the houses, and the disadvantages - the high cost (the outlet with the built-in UzO will cost about 3 times more expensive than the RCD installed on the distribution shield).

The UDO must be protected by a machine (the Uzo is not intended to disable high currents.).

There are devices that combine the functions of the Uzo and the machine.

Such devices are called Uzo-D with built-in protection from superflocks. These Uzo, the price is traditionally higher, but in some cases it is impossible to do without such protective shutdown devices.

For the most efficient use of UPS, it is preferable to install devices according to the following scheme:

• a) UZO (30 mA to protect the entire apartment, is installed in the panel on the staircase)
• b) Uzo (10 mA) for each line (for example, on the lines that feed the washing machine, the "warm" floors, etc., is installed in an individual intra-wood shield).

A convenient option, because when there is anything with electrical wiring or electrical appliances, only the corresponding line will be disconnected, not the entire apartment.

The disadvantages of this system are higher costs and the need to have significantly more free space. More than one UDO, as a rule, can be installed only in an individual intrahaft, specially designed for these purposes. In the usual shield on the staircase for this, as a rule, there is not enough space.

To protect the electrical equipment of the apartment with the use of the UZO, it is also necessary to take into account the danger of a short-term increase in the voltage in the event of a meek closure, a thunderstorm discharge on the power line, and other emergencies in the power supply service. As a result, it is possible to fail an expensive home appliance.

In this case, the use of an overvoltage protection device is very effective in conjunction with the RCD. In an emergency, with an increase in voltage, the varistor begins to drop an excessive stress on the ground, and the Uzo, finding the difference between the "flowing" and "flowing" back (the difference corresponding to the current "leakage" to the ground) will simply turn off the network nutrition without allowing the output from Building household electrical appliances, and varistor uzip. As a result, if you use the overvoltage discharger complete with the Uzo, then the power grid will simply turn off when increasing the voltage.

7. Task number 1

Calculate the specific power and light flux methods. The required number of luminaires with LL for general lighting of the room with electronic computers and place lamps on the plan of the room. At the same time, the minimum illumination is 400 lux., The height of the working surface from the floor is 0.8 m; The reflection coefficient of light from the ceiling RP \u003d 70 ... 50%, walls PC \u003d 50% and working surface PR \u003d - 30 ... 10%.

1. Determine the height, m, the suspension of the lamp over the working surface by the formula:

h \u003d H - H R- HC.

h \u003d 3.6 - 0.8 - 0.6 \u003d 2.2 m

where H is the height of the room, m; HP is the height of the working surface from the floor;

hC is the height of the light of the lamp from the main ceiling.

2. Calculate the illuminated area of \u200b\u200bthe room, M2, by the formula:

S \u003d 24 * 6 \u003d 144 m 2

where A and B - the length and width of the room, m.

3. To calculate the lighting by the method of specific power, we find the table specific power of the PM and the values \u200b\u200bof the QT \u003d 1.5 and ZT \u003d 1.1. For luminaires with UPS35 -4 x 40, the conditional number of the group \u003d 13 is first determined. At the same time, it is given for E \u003d 100 x 40 pm for E \u003d 100 x 40, so it should be recalculated for EMIN by the formula:

Pm \u003d 7.7 + 7.7 * 0.1 \u003d 8.47

RU \u003d PM Emin / E100

Ru \u003d 8.47 * 400/100 \u003d 33.88 W / m 2

4. Determine the total power, W, to illuminate the specified room by the formula:

R Total \u003d RU S KZ Z / (CT ZT)

Р Total \u003d 33.88 * 144 * 1.5 * 1.3 / 1.5 * 1, 1 \u003d 5766 W

where kz is the reserve coefficient, installed by the KZ \u003d 1.5; Z - coefficient of uneven lighting z \u003d 1.3

5. Find the number of lamps, pcs., By the formula:

NU \u003d Rsummarnoy / (NI RA)

Nau \u003d 5766/4 * 40 \u003d 36 pcs

where RA is the lamp power in the lamp, W; Ni - number of UPS35 -4 x 40

in the lamp, pcs.

6. To calculate the illumination by the method of the light stream, the index index is calculated by the formula:

i \u003d S / H (A + B)

i \u003d 144 / 2.2 * (24 + 6) \u003d 2.2

7. Find efficiency - the utility coefficient:

8. Find the light stream of the specified (accepted) FA lamp, LM:

9. Determine the required number of lamps, pcs., By formula:

NC \u003d 100 Emin S Z / Ni Fa k

NC \u003d 100 * 400 * 144 * 1.5 * 1.3 / 4 * 2200 * 45 * 0.9 \u003d 32

where k is the coefficient of shading for premises with a fixed position of the working (offices, drawing and other), equal to 0.8 ... 0.9; The remaining designations are decrypted above.

10. We are developing a rational scheme of uniform placement of lamps N to the room.

The distance, m, between the lamps and rows of these lamps are determined by the formula:

The focus of the light curve

L \u003d (0.6 ... 0.8) * 2.2 \u003d 1.32 ....1.76 m

l k 0.24 * L \u003d 0.24 * (1.32 ... 1.76) \u003d 0.32 ....0.42 m

When placing the Luminaires of UPS35 -4 x 40, they are usually rowed in parallel with rows of equipment or window openings. Therefore, the distances L and L k are determined.

11. If the design features of the room provide LP, M, between the lamps, then Lp 0.5 h. In this case, the placement of the lamps is better to conduct through the total length L by the formula:

l \u003d 32 * 1,270 \u003d 41 m

where LC is the length of the lamp, m.

12. Determine the placement of the total number of lamps indoors, pcs., By formulas:

N p \u003d 41/24 \u003d 1.7 2

N .C.P \u003d N C / N P

N .c.p \u003d 32/2 \u003d 16 pcs

N Society. \u003d N p * n .c.p

N Society. \u003d 2 * 16 \u003d 32 pcs

13. We check the actual illumination by the formula:

E \u003d 32 * 4 * 2200 * 45 * 0.9 / 100 * 144 * 1.5 * 1,3 \u003d 406 LC. 400 LC.

A -L P.C. - 2 L k / n .c.p - 1

L P.C. \u003d L C * N .C.P

L P.C. \u003d 1,270 * 16 \u003d 20.32

24-20.32 - 2 * 0.4 / 16-1 \u003d 0.19 m

B - 2 l k / n .p - 1

6 - 2 * 0.4 / 2-1 \u003d 5.2 m

Scheme of placement of lamps type 35-4x40

Choose the necessary fan, type and power of the electric motor and indicate the main design solutions.

• 1. Determine the area of \u200b\u200bthe room where mechanical ventilation is necessary:
  • S \u003d A * B
  • S \u003d 9 * 12 \u003d 108 m 2
• 2. Find a specific heat load:

q \u003d Qola / s

q \u003d 10 * 10 3/108 \u003d 92.6 W / m 2 400 W / m 2

3. Find air flow to remove excess heat:

L I \u003d 3.6 * qi / 1.2 * (T y - T n)

L me. t \u003d 3.6 * 10 * 10 3 / 1,2 * (23-16) \u003d 4286 m 3 / h

L me. s. \u003d L me. t. * 0,65

L me. s. \u003d 4286 * 0,65 \u003d 2786 m 3 / h

4. We find the presence of distinguished harmful substances in the room the required air flow, M3 / h, is determined by the formula:

L BP \u003d M BP / CG - C n

L BP \u003d 1.0 * 10 3 / 8.0 - 0 \u003d 125 m 3 / h

5. The calculation of the value of LB, M3 / h, lead by weight of the distinguished harmful substances in this room capable of explosion is determined by the formula:

L B \u003d M BP / 0.1 * C NK - C n

L b \u003d 1.0 * 10 3 / 0.1 * 20 * 10 3 - 0 \u003d 0.5 m 3 / h

6. We find the minimum exterior consumption (Lmin, m * m * m / h), determined by the formula:

L min \u003d 40 * 60 * 1,5 \u003d 3600 m 3 / h

Select the largest air consumption of 4286 m 3 / h \u003d l n

If l n\u003e lmin, then the value of l n is taken as final

• 4286 > 3600.
• 7. CTA 1-8 computers - LB \u003d 2000 m3 / h; Lx \u003d 9.9 kW.

KTA 2-5-02 - L B \u003d 5000 m 3 / h; L x \u003d 24.4 kW.

n B \u003d L n * k / l in

n B \u003d 4286 * 1/2000 \u003d 2,13 pcs

n x \u003d Qola * k / l x

n x \u003d 10 * 1 / 9.9 \u003d 1,012 pcs

n B \u003d 4286 * 1/5000 \u003d 0.86 1 pc

n x \u003d 10 * 1 / 24.4 \u003d 0,41pcs

Scheme for the placement of mechanical exhaust ventilation indoors