Cable Thickness & Connection for 3500-4000W Load: Installing 2 Sockets, Light Switch & Tray

I have a question in the room, I want to install 2 sockets and one light switch on the wall. I will put the cables in a tray screwed to the wall and use sockets above the plaster ones. I wanted to know what cable I need to use to withstand (this is with a margin) 3500-4000 W (about 5 meters of cable)?

The picture shows that he wants to connect the cable that will be able to withstand 3500-4000W (red) with the cable for the light switch (a 1.5mm wire is enough for the light itself), the only question is whether these wires must be twisted into a box or can they be connected by removing the insulation from the red one and braiding it with a yellow cable (the red one has an unbroken core) and then solder it thoroughly, apply insulating tape or heat shrink tube?

If this is not the appropriate department, please indicate the correct one, and I will put it there.

Such connections are not made. Where will the thicker wire start? In the switchboard? The lighting cable should also be connected there. You should use a 3 x 2.5 mm2 wire for the socket.

4000W / 230V = 17.4A, you can choose a cable according to the table.

For example, here you have stated that for such a current you would need a 20A fuse on a 25A cable, i.e. 4mm. You should rather solder the connection or use dedicated couplings. And also the ground wire.

kotlet_06 wrote:

4000W / 230V = 17.4A, you can choose a cable for it

Only that Polish single-phase sockets are designed for a maximum current of 16 A, so it makes no sense to give a larger wire cross-section.

Here you are right, I looked at the calculations, the fact is, it will not get more than 16A from the socket anyway. i.e. a 2.5mm cable and a 16A fuse. and then the maximum power of the receivers is about 3500W (probably, the cable will power several sockets in parallel, then the thicker wire will act as a bus)

kotlet_06 wrote:

probably, the cable will power several sockets in parallel, then the thicker cable will be used as a bus)

No! This is absolutely not allowed! If you do not have enough power in the sockets, you should pull a separate wire for each socket.

Shadowix wrote:

kotlet_06 wrote:

probably, the cable will power several sockets in parallel, then the thicker cable will be used as a bus)

No! This is absolutely not allowed! If you do not have enough power in the sockets, you should pull a separate wire for each socket.

Need to pull a wire to each socket from the fuse box? What's the difference between running 2 wires next to each other instead of 1 thicker one?

kotlet_06 wrote:

What's the difference between running 2 wires next to each other instead of 1 thicker one?

The fact that in the first case you have two circuits protected with the value of 16A each, while in the second case you have one circuit with a larger cross-section, also protected with the value of 16A.

You can protect the fuse with a larger value, but you are right that it is not safe to protect portable devices with such a large fuse, I return my honor.

luzik1980 wrote:

to put insulation tape or heat shrink tubing on?

I omit whether it is slow or not, etc., the previous speakers have already explained ... I am only interested in how to slide a heat-shrinkable sleeve over a cable without cutting it :?:

kotlet_06 wrote:

Can be protected with a higher fuse value

And what you will mount at the end of this wire, 32A single phase socket :?:



Added after 2 [minutes]:

kotlet_06 wrote:

that it is not safe to protect portable devices with such a large fuse

Some nonsense ... please justification, please.

kotlet_06 wrote:

Can be protected with a higher fuse value ...

Well, you can't.
And not because of portable / mobile receivers, but because of the socket's rated current of 16A.

I meant situations when two sockets on 1 line are loaded, e.g. 10A, which gives a total of 20A and does not exceed the rated current of a single socket

kotlet_06 wrote:

I meant situations when two sockets on 1 line are loaded, e.g. 10A, which gives a total of 20A and does not exceed the rated current of a single socket

The colleague wades on. There is a socket in the 16A circuit, it is a max 16A fuse

But it exceeds the rated current of the protection, which will trip after the lapse of time if the current value does not decrease. Although there is no threat to the equipment, the load capacity of the 2.5mm2 cable (depending on how it is laid) has its limits.

kotlet_06 wrote:

4000W / 230V = 17.4A, you can choose a cable according to the table.

For example, here you have stated that for such a current you would need a 20A fuse on a 25A cable, i.e. 4mm. You should rather solder the connection or use dedicated couplings. And also the ground wire.

The values in this table are probably for aluminum conductors.
It is probably a fragment of a book in the times of E. Gierek.
Maybe a colleague will place a scan of the entire page with the description of this table?

Below, I present a table of long-term load capacity for copper conductors with PVC insulation.
Leading multi-stranded cables in the cable tray is a way of arranging B2 .

As for the question about soldering the wires, it's out of date, in general, the concept has changed a bit in the room, I installed 2 sockets as in the photo, it was done without any soldering, the wires are 2 cables with a diameter of 2.5 mm (in the tray) for my needs are enough.


I have a question about the cable tray, as you know, they have mounting holes on the back, attach them with spaxes to the wooden paneling in the photo below, whether unused holes should be sealed with insulation or leave as they are, and one more thing, how should I do with these holes as will I screw the cable trays to the ceiling which is lined with polystyrene cassettes?



And one more thing, I have a small room near the room, I want to bring light to it, without a switch (if someone forgets to turn off and there is no view outside, it would probably be lit for quite a long time) because I wanted to install a LED bulb with a motion sensor, but I saw only with a motion sensor and a twilight sensor which is nonsense because in this room it is still dark and it would shine all the time, is there a way to trigger the dusk sensor and leave only the motion sensor in such a light bulb?

luzik1980 wrote:

I have a question about the cable tray, as you know, they have mounting holes on the back, attach them with spaxes to the wooden paneling in the photo below, whether unused holes should be sealed with insulation or leave as they are, and one more thing, how should I do with these holes as will I screw the cable trays to the ceiling which is lined with polystyrene cassettes?

No exaggeration, the current through these holes will not escape.

luzik1980 wrote:

however, I only saw with a motion sensor and a twilight sensor which is nonsense

The dusk sensor will not bother you in any way, because the motion sensor decides about lighting the lamp, and the dusk sensor allows you to turn it on when it is dark or even during the day (setting adjustment).

stanislaw1954 wrote:

luzik1980 wrote:

I have a question about the cable tray, as you know, they have mounting holes on the back, attach them with spaxes to the wooden paneling in the photo below, whether unused holes should be sealed with insulation or leave as they are, and one more thing, how should I do with these holes as will I screw the cable trays to the ceiling which is lined with polystyrene cassettes?

No exaggeration, the current through these holes will not escape.

luzik1980 wrote:

however, I only saw with a motion sensor and a twilight sensor which is nonsense

The dusk sensor will not bother you in any way, because the motion sensor decides about lighting the lamp, and the dusk sensor allows you to turn it on when it is dark or even during the day (setting adjustment).

I mean, I prefer to be safe than sorry, how would the cable behave if it was damaged, could it catch fire in such a trough, or would it go out on its own?

As for the LED bulb with a motion sensor and a twilight sensor, as you wrote that the first motion sensor will turn on, and then dusk, but when it turns off, then how in this room is it still dark? You also wrote about the setting, only that such bulbs should be disassembled as what because they do not have any knobs on the housing.

I used to have one with a motion and dusk sensor, but it was used to convert the halogen office lamp into a LED lamp and I threw it a motion and dusk sensor, but I don't remember what and how it was there.

luzik1980 wrote:

You also wrote about the setting, only that such bulbs should be disassembled as what because they do not have any knobs on the housing.

Not all lamps with a motion or twilight sensor have adjustable working time, because they can also have, for example, adjustment of the sensitivity of switching on with appropriate brightness / darkness. Those without regulation affect movement, and adequate darkness allows for activation. The lamp is on for the time set by the manufacturer, counting from switching on caused by a movement. During the lighting, the movement extends the lighting.

luzik1980 wrote:

I mean, I prefer to be safe than sorry, how would the cable behave if it was damaged, could it catch fire in such a trough, or would it go out on its own?

Whether it will be in the cover or not, if the cable should catch fire, the effects will be similar. Until some time and reaching the appropriate temperature, the cable (insulation) or the tray is not burning. The moment the ignition temperature is exceeded, the insulation will burn as well as the tray.

luzik1980 wrote:

I mean, I prefer to be safe than sorry, how would the cable behave if it was damaged, could it catch fire in such a trough, or would it go out on its own?

You bother your head with little real problems and I am asking where is the protective wire to the sockets :?:

The grounding is so obvious that I did not give it in the picture As for this bulb, I will take it if I can find it only with a motion sensor and see how it will perform.

luzik1980 wrote:

The grounding is so obvious that I did not give it in the picture

The color of the veins in the cable is also obvious (brown, blue and yellow-green) and the colleague on purpose gave a different
Where you connected the PE wire because in the first post there is a drawing with a dirty plan for connecting the circuit and so there are also two wires, probably that is also obvious and there is an invisible protective wire there.