Experience with 230V Power Supply on 15m Twisted Pair for Intermittent 500mA Load

Question

Hello,

at the outset, let me warn you that I know it's not the best idea, but what experience do you have with 230V power supply connected on a twisted pair (about 15m)?
It won't be a constant operation just up to 5s once in a while and a load of 500mA at most...
I can use one wire or combine two wires into one - I can't split 4 ...

al777 · Answer

I've never done that, but in my opinion at some point the insulation will fail and make a heater out of your cable (if you're lucky) or it will break through to the signal wires (if you're unlucky).

irekr · Answer

According to the catalog, each twisted pair withstands up to 500V - this is the test voltage. However, I do not recommend using the same cable for other purposes. E.g. net and bell or signaling. If you must control what with this cable, it is better and safer to install any low-voltage control system for higher voltage circuits, e.g. using relays.

Stary1952 · Answer

The fact that this is not the best idea (abusing the regulations) has already been written by my predecessors. Also take into account the voltage drop that will occur under these conditions. Regards .

petersuchy · Answer

Relax - it will only be used temporarily - and the voltage drop can occur up to 170V without consequences ;]
As for the current, it will be about 50-100mA - 500 I wrote with a margin ;]
It seems to me that when it comes to overheating, it will not occur, so melting the insulation is out of the question - I'm only worried about punctures ...
but none of the other wires will be connected to neutral, which in my opinion makes it less likely to occur...
Another issue is interference - but the installation is organized in such a way that during the flow of 230V electricity, no transmission will be carried out on the other wires ...

What do you think about this reasoning??

tzok · Answer

500mA at 230V for 15m is a lot (>100W) for a twisted-pair cable, with the flow of such current in adjacent wires, significant voltages can be induced, dangerous for Ethernet card inputs (they are galvanically separated, but this does not mean that AC with high amplitude will not damage the card's controller) unless this twisted pair will not be used for Ethernet, but only for control.

In the case of PoE solutions, the power does not exceed 10-15W and direct current is usually used.

petersuchy · Answer

Unfortunately, the repair team messed up the case and I'm missing my veins ... ;/

Fyszo · Answer

Remember that even if the insulation does not melt, its slight heating and on any bends the veins will dangerously 'emerge' from the warm insulation, which may lead to a puncture. And what does it mean that there will be no neutral there? If it will be for powering electronics (intelligent building), I suspect that it must be neutral.
The team was commissioned to do the installation in the conduits (or channels on the walls) - then you would add additional cables.

petersuchy · Answer

This means that I have 3 electrical wires 1.5mm2 and I need 2 more ... ;/

Stary1952 · Answer

I do not know what you want to control it, but if you have a single-phase installation at home, maybe you could "borrow" zero from another point and use the 3X1.5 wire to control 3 different receivers in phase?
Regards .

MARR · Answer

A brave idea to run 230 V over a twisted pair.
I wouldn't have thought of it, and maybe I'll let go of my strength right away!!!

Seriously, it's probably the only way out
cable for 230 V - in some floor masking
e.t.c.

MARCIN.SLASK · Answer

There are not many brave ones. Recently, the customer's ceramic hob stopped heating. I look, there it is powered by an old symmetrical antenna cable. Unfortunately, it burned out after a few years. The client was very lucky that the phase and not zero.

I advise against using cables that are not intended for the intended purpose.

MARR · Answer

True Kamikaze.

zdzicho44 · Answer

When it comes to overheating, it will certainly not occur with such parameters. It will emit in the cable over a section of 15 m 1 W. In such a short time, it will not increase the temperature in any significant way, and even this increase will be difficult to measure. Insulation quite poor for 325V peak.

al777 · Answer

By the way - regarding this insulation strength: renovation and construction teams usually buy the cheapest type of twisted pair cable you can find in a friendly electrical wholesaler - in the case of such goods, declarations of strength parameters often resemble the pious wishes of the manufacturer. The second thing - I've seen a couple of times how such a twisted pair got a short circuit between one pair as a result of repeated stepping on it. So it's enough that your builders used the help me pull because it's hard method on only one section (and they use it with pleasure) and I see this resistance in black.

szczepanr · Answer

Hello,

Performing such an installation in this way is the height of unprofessionalism, amateurishness and irresponsibility.
If you need 230V power supply, use dedicated cables and wires. Think about laying them in cable trays, masking plates, or placing them under the plaster.
Regards

Experience with 230V Power Supply on 15m Twisted Pair for Intermittent 500mA Load

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