Electrician in a small and medium office, part one
If you rent an office in a large center, where there is SCS and everything is cool, then this note is not for you. But if you move to a room transferred from the housing stock, then this article will be useful for you. I will talk about possible problems with the electrician and how to prevent them.
The most common problems in the premises are the following: a power outage, equipment damage, a fire.
A power outage is the most frequent and rather unpleasant. And in most offices uninterruptible power supply is not observed. Losing a freshly painted layout, data on the server, losing communication during an important conversation is all a loss.
')
If you do not consider the electricians and whims of RAO UES, then the most frequent reason is network overload or short circuit. If you're lucky, the machine will work and cut off the current. If you are unlucky and the machine does not work, the wiring will light up.
Network congestion occurs when the power of consumers exceeds a certain acceptable value for which the wiring is calculated. You cut in, say, an air conditioner, an electric heater, 20 computers, a kettle, a coffee maker ... oops, the lights went out. Keena will not - electricity is over.
In the premises of the former housing stock wiring was calculated according to Soviet standards. Then there was no teapot for 2 kilowatts. For the whole apartment, if it was equipped with an electric stove, they allocated about 7 kilowatts. If the house is gasified - then kilowatt 5, if as far as I remember. And the wires in the old houses, mostly aluminum, but the wiring is old, with microcracks. And the veins are not very thick. And contacts - where they left, where they burned.
But even in this situation, it would be possible to avoid problems, but bad luck, there are usually only two or three power supply groups (two or three automatic machines on the stairs, respectively). And the same teapot, because of which "broke traffic jams", hung on the same wire, on which your server and half of the computers, and should not be so.
The crime of a small degree of severity is an attempt to immediately turn on the machine on the stairs. If the wiring is not allowed to cool, the next overheating can be fatal, the insulation will collapse. The insidiousness of such destruction is that closures may not happen in your presence. You have left, but there is a leak from the damaged wiring, the place is heating up ... hello, office!
A serious crime is the replacement of machines with more powerful ones. Knocked the cork once, twice, third. And then some "smart guy" advises to replace the 16-amp by 25-amp. Like, weak cork, worn out. Or even bypassing, “putting a bug.” It is necessary to pray for those machines that were knocked out - they saved you.
For example, your wiring is designed for a continuous current of 16–18 amperes, and 16 ampere machines are cut down. Set 25 amps and what happens? Machines are no longer cut down, and the wiring is heated under the action of a larger current, the insulation wears out ... hello, office!
What to do? First of all, driving into a new office, find out where your fuse box is located. It will be useful when they are cut down. And find out exactly where your fuses, so as not to click everything, chopping off the neighbors or other computers in your office. See also which fuse is responsible for what.
Inspect the wires that run from your machines to the terminals. In our new office, inspecting the wires, I saw charred insulation and fused aluminum. This means that there were overloads or poor contact on the dashboard. What then was going on indoors? Inside, I found, for example, twisted copper and aluminum wires (this is very bad from a security point of view).
Also make sure that the fuse rating does not exceed a reasonable one. Typically, for a former dwelling, a maximum of one fuse is 16 amps. If you see, say, 25 amps, and the old wiring is a time mine.
Look at the material and the cross-section of wires that go into the room, as well as go to the lamps and sockets. Aluminum is bad. Connections worse, under screw terminals weakens with time, resistance is higher, it heats up more often.
The wiring must be copper, and its cross-section - corresponding to the load. For example, 1 square millimeter of a copper wire can hold a current of 6–8 amperes for a long time. Accordingly, it is possible to land a load of 8A × 220V = 1760W on this wire.
Group wire on the lighting line must be at least 1.5 "squares" in copper, and on the socket lines - at least 2.5 "squares". Particularly powerful consumers, like air conditioners, should be planted on separate wires, with separate automatic machines. And the cross section count individually.
Electrical board is a box in which various devices are mounted. Most often they are automatic, but there may be different relays, RCDs, and others. The input cable comes from the ladder to the shield, and many cables go from the shield to the rooms and compartments.
First, we figured out where in which room the workplaces will be located. They thought about the location of sockets, lamps, switches. Then they calculated the load and, based on it, thought out the power supply groups.
For example, servers and PBX are powered separately, sockets in each room are separately, lighting is separately, room by room. The kitchen, where there is a water cooler, and a coffee machine will soon appear - separately.
If, say, a defective power supply unit short-circuits and cuts down one room, then all the other rooms, the server room, as well as the lighting, will not be left without power. When distributing power groups, consider this. And never put lighting on one group with sockets. It is better to buy another piece of cable and one more automatic machine than to lose half the day’s work of several employees.
As a result, each lighting group hangs on a 1.5 “square” copper cable and a B6 slot machine. Sockets hang on cables 2.5 "squares" and machines B10 or B16, depending on the required load. The number indicates the number of amps, and the letter - the response characteristic. We have almost everywhere put C, in Europe - B, they will work faster.
When you choose the nominal of machines, remember that it must be either equal to or less than the current for which the wiring and your sockets and switches are designed.
Do not save on components. I recommend machines from ABB, Legrand and Schneider Electric. Do not buy Chinese and pseudo-Russian units. Save on everything from assembly to finishing materials. This is your safety. And buy only in large offices. Machines fake almost like medicine.
Let the electrician who collects the flap, mark which machine he is responsible for, and give you a scheme.
In the next part I will talk about laying cables, what is RCD and what other useful devices can be in the shield, as well as about burning out zero, protection against overvoltage and other interesting things. That's just whether to place on the "Habré" the next part, I have not decided yet, and there are good reasons for that.
Kinah won't, electricity is over
The most common problems in the premises are the following: a power outage, equipment damage, a fire.
A power outage is the most frequent and rather unpleasant. And in most offices uninterruptible power supply is not observed. Losing a freshly painted layout, data on the server, losing communication during an important conversation is all a loss.
')
If you do not consider the electricians and whims of RAO UES, then the most frequent reason is network overload or short circuit. If you're lucky, the machine will work and cut off the current. If you are unlucky and the machine does not work, the wiring will light up.
Network congestion occurs when the power of consumers exceeds a certain acceptable value for which the wiring is calculated. You cut in, say, an air conditioner, an electric heater, 20 computers, a kettle, a coffee maker ... oops, the lights went out. Keena will not - electricity is over.
In the premises of the former housing stock wiring was calculated according to Soviet standards. Then there was no teapot for 2 kilowatts. For the whole apartment, if it was equipped with an electric stove, they allocated about 7 kilowatts. If the house is gasified - then kilowatt 5, if as far as I remember. And the wires in the old houses, mostly aluminum, but the wiring is old, with microcracks. And the veins are not very thick. And contacts - where they left, where they burned.
But even in this situation, it would be possible to avoid problems, but bad luck, there are usually only two or three power supply groups (two or three automatic machines on the stairs, respectively). And the same teapot, because of which "broke traffic jams", hung on the same wire, on which your server and half of the computers, and should not be so.
What to do and what to do
The crime of a small degree of severity is an attempt to immediately turn on the machine on the stairs. If the wiring is not allowed to cool, the next overheating can be fatal, the insulation will collapse. The insidiousness of such destruction is that closures may not happen in your presence. You have left, but there is a leak from the damaged wiring, the place is heating up ... hello, office!
A serious crime is the replacement of machines with more powerful ones. Knocked the cork once, twice, third. And then some "smart guy" advises to replace the 16-amp by 25-amp. Like, weak cork, worn out. Or even bypassing, “putting a bug.” It is necessary to pray for those machines that were knocked out - they saved you.
For example, your wiring is designed for a continuous current of 16–18 amperes, and 16 ampere machines are cut down. Set 25 amps and what happens? Machines are no longer cut down, and the wiring is heated under the action of a larger current, the insulation wears out ... hello, office!
What to do? First of all, driving into a new office, find out where your fuse box is located. It will be useful when they are cut down. And find out exactly where your fuses, so as not to click everything, chopping off the neighbors or other computers in your office. See also which fuse is responsible for what.
Inspect the wires that run from your machines to the terminals. In our new office, inspecting the wires, I saw charred insulation and fused aluminum. This means that there were overloads or poor contact on the dashboard. What then was going on indoors? Inside, I found, for example, twisted copper and aluminum wires (this is very bad from a security point of view).
Also make sure that the fuse rating does not exceed a reasonable one. Typically, for a former dwelling, a maximum of one fuse is 16 amps. If you see, say, 25 amps, and the old wiring is a time mine.
Look at the material and the cross-section of wires that go into the room, as well as go to the lamps and sockets. Aluminum is bad. Connections worse, under screw terminals weakens with time, resistance is higher, it heats up more often.
The wiring must be copper, and its cross-section - corresponding to the load. For example, 1 square millimeter of a copper wire can hold a current of 6–8 amperes for a long time. Accordingly, it is possible to land a load of 8A × 220V = 1760W on this wire.
Group wire on the lighting line must be at least 1.5 "squares" in copper, and on the socket lines - at least 2.5 "squares". Particularly powerful consumers, like air conditioners, should be planted on separate wires, with separate automatic machines. And the cross section count individually.
What did we do
- First, of course, thought of everything. Where and what jobs, what load, what should be independent of what. What to buy, how much it will cost, where you can order.
- Replaced introductory machines. There were two 25 amp amps, we set one for 32 amps.
- Replaced input cable. Previously, two aluminum wires of some frail section went into the room. Now - NYM-copper cable, cross-sectional area of ​​6 square millimeters, in triple insulation. Thus, the cable just stand 32 amps, and even with a margin. And yet, the cable is three-core, the sockets will be with zeroing.
- The wire from the machine to the terminals on the shield also replaced. Burnt and melted wire could not be left.
- Disconnected and tore out the old wiring, removed the old sockets and switches. Firstly, the sockets did not meet European standards (no zeroing). Secondly, they were already old, rather worn, in some places with traces of soot.
- Now - the most interesting. In the office we made the hardware. There will be a rack with servers, office PBX, input of Internet lines and our electrical panel. I will tell about it in more detail.
Electrical board is a box in which various devices are mounted. Most often they are automatic, but there may be different relays, RCDs, and others. The input cable comes from the ladder to the shield, and many cables go from the shield to the rooms and compartments.
First, we figured out where in which room the workplaces will be located. They thought about the location of sockets, lamps, switches. Then they calculated the load and, based on it, thought out the power supply groups.
For example, servers and PBX are powered separately, sockets in each room are separately, lighting is separately, room by room. The kitchen, where there is a water cooler, and a coffee machine will soon appear - separately.
If, say, a defective power supply unit short-circuits and cuts down one room, then all the other rooms, the server room, as well as the lighting, will not be left without power. When distributing power groups, consider this. And never put lighting on one group with sockets. It is better to buy another piece of cable and one more automatic machine than to lose half the day’s work of several employees.
As a result, each lighting group hangs on a 1.5 “square” copper cable and a B6 slot machine. Sockets hang on cables 2.5 "squares" and machines B10 or B16, depending on the required load. The number indicates the number of amps, and the letter - the response characteristic. We have almost everywhere put C, in Europe - B, they will work faster.
When you choose the nominal of machines, remember that it must be either equal to or less than the current for which the wiring and your sockets and switches are designed.
Do not save on components. I recommend machines from ABB, Legrand and Schneider Electric. Do not buy Chinese and pseudo-Russian units. Save on everything from assembly to finishing materials. This is your safety. And buy only in large offices. Machines fake almost like medicine.
Let the electrician who collects the flap, mark which machine he is responsible for, and give you a scheme.
In the next part I will talk about laying cables, what is RCD and what other useful devices can be in the shield, as well as about burning out zero, protection against overvoltage and other interesting things. That's just whether to place on the "Habré" the next part, I have not decided yet, and there are good reasons for that.
Source: https://habr.com/ru/post/40552/
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