Electrical wiring and power use - Domestic

Factual Questions
1

I am living at the moment in a small apartment where the electrical wiring is as someone else wonderfully put it “Rated to protect the fuses”

I have lots of electrical stuff including fridge, AC unit, TV, computer, hot water shower and on and on.

I have always believed that there are different wiring gauges for different uses, like 2.5 for power and 1.5 for lighting.

In my situation the wiring inside the apartment, I think is OK, but the worry is a short length of wire from the meter outside to the distribution box inside the apartment. This length of wire is 1.5 gauge which I always considered only as suitable for lighting circuits.

Surprisingly I am not having any problems with the obvious overload of the wire from meter to distribution box, it doesn’t even glow, but my question is is it costing me more units (money) by the electricity having to “squeeze” through this bottleneck? In other words if I were to increase the gauge to say 2.5 would it save me money?

Don’t know if I explained this well – hope some one will understand what I’m trying to say. :confused:

Also :slight_smile: about room cooling fans. They all have about three buttons for speed settings. My question is if I select a low speed setting will I save electricity and the ecology or is the reduced speed just taken up by a resistor in the fan and make no difference to the power consumption.

Thanks.

2

I think safety is liklier to be a problem than spending more money because of the bottleneck.

A few thousand watts is not hard to consume in your appartment, but even a few hundred watts being dissipated in a short length of wire would melt the insulation. Note that what matters is how many watts are actually lost in the wire, not how many are being transported by it. Losing watts adds to your bill and, more importantly, generates heat that causes hazards. Transporting the watts from the meter to your appliances doesn’t cause any trouble - in fact it’s hard to detect without special instruments.

BTW, where do you live? Wire gages like 1.5 and 2.5 are unfamiliar to me - I live in the USA and here 14 or 16 would be a light gage for lighting while 10 or 12 would be a heavy gage for distributing power to appliances.

3

I assume your “1.5 gauge” and “2.5 gauge” refer to conductor cross sections of 1.5 mm^2 and 2.5 mm^2, respectively? If that’s the case the wiring is definitely underdimensioned, even a fire hazard. I don’t know about wiring codes in your country, obviously - here in Germany we fuse 1.5 mm^2 wiring with 16 A, which obviously isn’t the case if you run an apartment with A/C and a hot water boiler from that. What country are you in?

You should look at the rating of the first fuse ‘upstream’ of that wire and choose conductor gauge from that. Better still, have a properly trained electrician look at your apartment’s wiring for your safety’s sake - if it’s not properly done in that critical place it may well be not up to code in other places.

4

I really really hope that the 1.5 you are looking at is not 1.5mm!!!

EEEEEEEEEEEEEEEEEEEKKKKKKKKKKKKKKKK!!!
If we are talking UK supplies on 230v, 1.5mm cable might be good for perhaps 15amps.

If we talking 110v the situation is actually worse, because to get the same power you need much more current.

You should be looking at much much greater size cable.

I would usually use 20mm cable here, minimum, even in an apartment and even with very light loading.

What you really must consider is that the supplier fuse will be 60amps, this wiring is dangerous, if there is an overload this cable WILL melt, not maybe or perhaps.

Note that an overload is when there is some sort of fault that draws a higher current than normal, but not necessarily enogh to blow the fuse.

The cable must be capable of continuously handling overload current, it absolutely must be able to handle 60amps, in fact, given the tolerance of fuses, I would say it really needs to handle 70 to 80 amps.

There are other issues that you may not be competant to understand, such as earth loop impedance and disconnection times, and even if the cable were able to handle the current, the earth resistance on such small section wire may cause plenty of other problems.

I’m actually doubtful the situation is as it would appear, I can’t see you being able to run a shower through 1.5mm cable, unless its to drive just an electric booster pump and the heat for the shower is done by gas.

5

To actually answer your questions:

  1. A smaller wire size will not result in higher electrical bills.
  2. Running your fan on ‘low’ should mean less electrical consumption, which would mean lower electrical costs.
6

Hmm, now actually answering the questions might seem like a great idea, however, being an electrician, I personally think that the imperative is to ensure the continued longevity of the OP.

Summing up, screw the questions and answers, get it sorted out before you die.

7

How can you tell that the power line into your apartment is 1.5 gauge ? Assuming you are correct and assuming that all the apartments in your building are individually metered, I’d get the hell out of there right now !

8

I must be going nuts. The way I figure it 1.5 mm is roughly equivalent to #14 US wire gauge which is used for 15 Amp household circuits. Wire with a diameter of 2.5 mm is roughly equivalent to #10 US gauge and is used here for 30 Amp circuits.

1.5 mm = 0.059 in. #14 dia. = 0.064 in. carrying capacity of 1.5 mm = 12 Amp.

2.5 mm = 0.098 in. #10 dia. = 0.102 in. carrying capacity of 2.5 mm = 27 Amp.

Look at your fuse or circuit breaker panel to see if the various circuits are equiped with fuses/breakers of the currect current rating.

9

As a former electrician, I can say with all certainty that it depends.

10

The power dissipated in the “short” length of 1.5 wire at 30 A. would be about 2.7 W/ft. With adequate ventilation for the lead it isn’t disasterously unsafe but I would make sure that nothing interfered with good air circulation.

I think I would speak to the apartment owner about it.

11

This whole OP sends my BS-ometer into amber. Did you just suddenly decide one day that you’d check out the gauge of the wire coming into your apartment? What’s the background?

12

Wow! Thanks for all the replies. OK I’m in Thailand but this kind of situation is common in most of the “developing” world. I realize it is sometimes difficult to comprehend the way things work outside of a “western” system but this is how things are here – it works! What’s the problem???
No I am not going to run screaming out of my apartment, it will only be taken by some one else. I am keeping a watch on the wiring inside and have identified + & - and installed my own grounding rod to stop getting shocks from the computer and TV chassis.
As for the difference in gauge when I said 1.0 or 2.5 I did indeed mean mm^ the UK system and I have looked at the short wire from meter to distribution box and it is flat twin without earth and marked 1.5mm^ and yes it is 250v.
As to background:- Here one looks for a house apartment whatever at a reasonable rent. If you are a foreigner even with a Thai wife this is not easy as all foreigners are RICH so grab what you can before the price goes up. Anyway like everyone everywhere you see an apartment it has potential your darling is smiling so you say OK we take it. It is only once you move in and put your stuff in place that you see some of the problems.
As I said in my original post there is not a problem with the wiring it is just that the meter is spinning at such a rate to compete with the monthly rent,
:frowning:

13

Shoot, if the OP is installing his own ground rods and such, he may as well pull the meter and replace the wiring to the panel. Safer than burning the place down. 'Course I would try to get the owner to pay for it and/or contact an electrician first.

14

If that is 250 V. service then the current I used in the example of a previous post needs to be divided by two for the same load power and that reduces the loss in the line by a factor or 4. It would appear that your apartment is wired for 250 V., 15 or maybe 20 Amp service which might be standard for such residences in Thailand.

15

Yes, it could.

If it’s small enough to be under-sized for the current passing thru it, it will overheat, thus increasing it’s resistance, and resulting in more electricity wasted as heat.

16

Thanks for all your input. I think the basic questions have been answer. An overloaded section of wire may increase electricity consumption due to the resistance, but safety is more of a concern.
A bit more background as there seems genuine interest and concern from all you nice people. The apartment wiring was not really designed for the loads I am putting on it. Most people just have a TV and fan.
The building is constructed of cement blocks with the all the wiring run on the surface of the walls, there is no concealed wiring so little risk of fire hazard. I can clearly see the short wire in question and it never feels hot to the touch. I will keep my eye on it.
And is that correct if I select a low speed setting on the fan it does use less electricity?
Thanks all again. :slight_smile:

17

Yes, almost certainly. Nearly all modern fans have electronic circuitry (maybe just a couple of diodes) that provides less electricity to the motor on low speed, thus using less electricity.

You might be able to find an antique fan that actually reduces power to the fan motor by using resistors, but they’re really rare. Sch a fan would use the same amount of electricity no matter what speed it’s running. On low speed, the resistors dissipate the excess electricity as heat. (Having a cooling fan that puts out a lot of heat is rather conter-productive!) Such a fan would be easy to recognize: it’d likely be big, clunky metal with a part that gets quite hot. No plastic on it at all; that would likely melt.

If you have such a fan, you can probably sell it as an antique for enough money to buy several small, efficient modern fans!

18

It depends on the load.

If the power dissipated by the load is a function of voltage (electric heater, etc.), then undersized wiring will reduce your electric bill.

If the power dissipated by the load is not a function of voltage, then undersized wiring will increase your electric bill.

19

My suggestion for you would be to check that someone else isn’t on your meter as well.

Do this by throwing the master fuse/circuit breaker in your panel. You should be using no (ok, very, very nearly no) power. If the meter is still spinning quickly, either:

  1. someone has tapped into your distribution system. (post meter, you pay)
  2. the meter is faulty.

This probably isn’t the case, but from the description of “housing acquisition” that you posted above, it wouldn’t surprise me to find that someone may have thought the “rich foreigner” could help him pay for his electricity. Heck, it happens here in the US every once in a while.

good luck.

20

Yes, and god knows he probably needs that 7 cents a year he’ll be saving. On this small a scale, I will have to stand by my answer.