Electric Meter Change

[55Jay]

The 15 amp meter out on the soi pole toasted. We had been having power drops leading up to it and then it just quit.

Electric folks say it is because we are drawing more power to the house now, and I go along with that idea.

They advise against putting in a 15 amp as eventually the same thing will happen.

My question is they told us the only upgrade option is 30 Amp (around 7,000 baht). Is there no increment between 15 and 30?

Am I correct in thinking having a 30 amp meter would not provide any more power to the house unless I change the line from the street to the house?

[Crossy]

You must have seriously overloaded your meter to kill it, these things regularly handle a 100% overload without flinching.

There is no increment between a 15/45 (which you had) and a 30/100.

You will be able to draw more power without toasting the meter even on your existing cable, however, MEA/PEA may not actually connect a 30/100 unless you upgrade your incoming cable to 35mm²

You you know how much you're actually pulling? If not what are your major loads?

What is the rating of your incoming breaker? Size of your existing cable?

[Pib]

Jay,

When you say a 15A meter, do you mean a 5/15A or 15/45A meter?

Pib

[Crossy]

Jay,

When you say a 15A meter, do you mean a 5/15A or 15/45A meter?

Pib

Dashed good point old bean, a 5/15 isn't enough for a big shed

[Pib]

Jay,

When you say a 15A meter, do you mean a 5/15A or 15/45A meter?

Pib

Dashed good point old bean, a 5/15 isn't enough for a big shed

But where my MIL lives out in the province that is a common size. Now can she really distribute that incoming 15A capacity through her CU? No? Why you may ask? Because in her CU she has a 10A master circuit break. But hey, that 10A is enough to run a few lights, a few fans, two TVs, two frigs, a small water pump which stay turned off most of the time, and occasionally the small A/C...and she never has all of these items turned on at the same time. And I'm not sure the small split A/C is even hooked into the CU...I think they just hooked it into the incoming line up in the ceiling and it has a separate combo switch/breaker to control it. Oh yea, all two wire...no earth/safety/third wire. Typical of many Thai homes.

Edited July 2, 2013 by Pib

[55Jay]

Pib, don't know about the " / " between the numbers, but I'll look at it in the AM. I think you are right though, this meter is orig from long ago when the parents had a hut, fridge, fan and a light bulb.

Happy to hear 15 to 30, thanks Crossy. I wasn't clear if they just didn't have any, or they were trying to sell me a bill of goods, or indeed 30 was the next size up.

[Pib]

When you look at the meter face plate it may not list the amperage as " XX/XX" but probably like XX (XX). Ex: 5 (15), 15 (45), or like my meter 30 (100). The number within ( ) represents the max current capability although I think it's fused at something higher than that and the first number is the amperage the meter is calibrated at. So, for example, my 30 (100) meter means it's a 100A service and the meter was calibrated at the factory at 30A. I read somewhere that the calibration amps is usually around one--third of the max capability based on the amperage a typical residence will routinely pull. But I sure know I don't routinely pull 30A...with one 18K BTU running pretty much 24/7 along with lights/TVs/frigs/etc., I'm usually pulling around 12A for most of the daylight hours...come night time another 18K BTU gets turned on so I'm pulling around 20A during the night when both A/C compressors kick in at the same time. But turn on the washing machine, dryer, microwave, more A/Cs, water heaters, etc., the amps can go up significantly.

Edited July 2, 2013 by Pib

[aarn]

Had similar problem in Australia. Wasps and such malevolent hexapods were building sandcastles. Worth a look. AA

[Markaew]

You can't just assume the cable you have is the correct size for the next larger meter where you may think "it can handle it". Granted most cable that is installed is usually larger than needed but don't ignore it. You need to at least match your cable size to your meter amperage and you need to account for distance as well which means voltage drop. You didn't mention about distance. Some meters are 50 to 75 meters away.

[ericjt]

I think it's already been covered Jay, but the size of the meter has nothing to do with how much electricity you can pull. It just measures what you pull and use. So getting a larger meter might keep it from frying, but it won't increase how much electricity you can use.

[Garry]

Handy tool to check out your home consumption: http://home.iprimus.com.au/foo7/energy.html

oops: not a load tool, my bad

Edited July 3, 2013 by Garry

[AjarnMartin]

Good question Jay

I'm certainly no expert on anything electrical and have often wondered why my Combi Microwave from the UK cannot be used without melting plugs. Is it because of this 15/15 business?

In my kitchen I also have an extension lead plugged into a wall socket and when I simultaneously use the kettle, toaster and rice cooker the extension just trips out. One device at a time works OK.

Where can I find advice on this which is written in Mickey Mouse, layman's terms because I'm currently designing a house?

Many thanks.

[jocko]

Good question Jay

 

I'm certainly no expert on anything electrical and have often wondered why my Combi Microwave from the UK cannot be used without melting plugs. Is it because of this 15/15 business?

 

In my kitchen I also have an extension lead plugged into a wall socket and when I simultaneously use the kettle, toaster and rice cooker the extension just trips out. One device at a time works OK.

 

Where can I find advice on this which is written in Mickey Mouse, layman's terms because I'm currently designing a house?

 

Many thanks.

I can't help about anything electric but as a observation I am amazed that if you see welders working around and about there old ropey welding machine is plugged into the nearest wall socket and being a welder myself I know welding can draw a lot of power but they seem to get away with it you dont even see many of them using small inverter welders.

Strange

[Gerrit]

My meter burnt a few day ago and had to be replaced. The cables overheated where they are screwed into the meter. This is a very common electrical problem. If the screws are not tightened properly it causes a high resistance joint with increased load and thus the burning of the cable.

[Pib]

Good question Jay

I'm certainly no expert on anything electrical and have often wondered why my Combi Microwave from the UK cannot be used without melting plugs. Is it because of this 15/15 business?

In my kitchen I also have an extension lead plugged into a wall socket and when I simultaneously use the kettle, toaster and rice cooker the extension just trips out. One device at a time works OK.

Where can I find advice on this which is written in Mickey Mouse, layman's terms because I'm currently designing a house?

Many thanks.

I can't help about anything electric but as a observation I am amazed that if you see welders working around and about there old ropey welding machine is plugged into the nearest wall socket and being a welder myself I know welding can draw a lot of power but they seem to get away with it you dont even see many of them using small inverter welders.

Strange

The surge current is brief for a second or so when they spot weld...and since most circuit breakers are slow reacting they won't trip for those brief surges if the amps is not too far above their trip-point and wires can handle much, much more current than what they are rated for as their rating is based on "continuous" current usually over a 2-3 hour period. Plus, the Thai welders could care less what damage it might do to your house wiring/circuit breakers/etc.; they'll just give you those puppy dog eyes if something shorts out, say they don't know what happened, just blame it on your poor wiring, etc.

Edited July 3, 2013 by Pib

[HAL9000]

I don't understand these numbers. I don't see a number on my main breaker, but my breaker box has 3 breakers at 32 amps each and 7 breakers at 20 amps. One of the 32s is dedicated to a 6000 watt shower heater, and I easily run up electric bills at 3000 per month. I don't see how a 15/45 or even 30/100 could service this house.

[yieldman]

The power calculator mentioned before :

http://home.iprimus.com.au/foo7/energy.html

estimates the power use.

From this work out the current (A) by dividing the Watts by the voltage (220 - 240 in Thailand).

Equipment using a lot of power (Like electric heaters, plug in airconditioning, dishwasher, cookers) is typically 2400 Watts or 10A. Everything else combined (lights, TV, computers and so on) typically draws less then 10A .

A slow or intermittent power failure indicates a bad connection. If the house draws to much power, the main fuse would blow instantly.

A small house European or Australian house would have 3 x 15 A circuits and one 10 A circuit plus one or two dedicated circuits for hotwater and electric oven . So 55A plus 15A for hotwater plus 15A for oven or 45 A for Electric hotplates .

So a 15/45A meter (one would assume with a 45A fuse) could supply a hotwater unit, kettle, airco and some small stuff simultaneously.

When building a house get at least a 30/100A meter.

All electrical equipment has to have the voltage (220-240V) and Power details (in W). Divide the Power (W) by the Voltage(V) to get the current (A)

E,g, a small 2.5 KW airco (2.5Kw = 2500 W) will draw 2500/240 A or a bit over 10A.

A 7 Kw split system Airco will draw 7000 / 240 or a bit under 30A

[Pib]

I don't understand these numbers. I don't see a number on my main breaker, but my breaker box has 3 breakers at 32 amps each and 7 breakers at 20 amps. One of the 32s is dedicated to a 6000 watt shower heater, and I easily run up electric bills at 3000 per month. I don't see how a 15/45 or even 30/100 could service this house.

Keep in mind each of those breakers feeds a particular area/electrical item in your residence. Say one breaker feeds all the outlets in your living room, one breaker feeds all the outlets in your kitchen, one breaker feeds your shower heater, one breaker feeds your split A/C, etc...etc...etc. Now just because you living room breaker is 20A does not mean you are drawing 20A...highly, highly unlikely because you probably only have the TV, the TV box, the stereo, a few lights, and a fan turned on...all of which are probably drawing a total of around 5A. OK, turn your A/C on which is probably has a 20A breaker but its only going to pull around 8A if a 18K BTU...or down around 5A if a 12K BTU. Now that 6000W heater will draw around 27A while it's turned on during those minutes you are taking a shower; zero after it turned off and you are drying off the body you are so proud of.

I guess what I'm saying, circuit breakers feeding an area are really meant to ensure the "wires" feeding that area are not over-amp'ed and of course to kill power to that area when a short occurs that draws BIG amps for a few seconds.

Heck, in my home I have 7 split A/C, of course normally only 2 are running at once...one time 4 were running at once, two 6000W shower heaters but only one is ever in use at once, a washer, a dryer that draws around 25A when running, a microwave that draws around 10A when cooking (close to nothing when in standby), 3 frigs (frigs don't draw much current at all), lights, fans, TVs, etc...etc...etc. But during the day with no A/Cs running and just various pieces of electronics like TVs/TV boxes in standby mode, microwave clock running, one TV and one TV box on, one or two fans runnings, I'm only drawing about 2-3 amps. I've actually measured the total current/amp draw with my clamp-on ammeter at the electrical service entrance to my house/the wires leading from the meter going to the house.

Tturn one 18K BTU A/C on and it adds another 9 amps (when the compressor kicks in...around 0.5 amp when not kicked in)...I'm now up to around 12 amps...come night time we have another 18K BTU A/C that runs all night so that's another 9 amps which gets me up to around 21 amps (with both A/C compressors kicked in...then drops down to around 4 to 5 amps total house amp draw during those minutes the A/C compressor are not kicked in.

By the way, I have a 100A service meter. Now, if I ever turned on all 7 A/Cs at once, both 6000W heaters, my washer and dryer, and just everything in the house then I would blow my main circuit breaker, which is 80A, in a heartbeat; however all those items will never be turned on at once in the real world.

All those circuit breakers in your main box don't reflect the amps you are actually drawing; they only serve as safety devices to limit the max amps going to a certain area/electrical device.

[55Jay]

We have the opportunity to revert to a new 15 and, I'm told, get back the balance paid for the 30 and put it toward our current "estimated" bill of 8,000 baht for May and June. This is why I've asked the questions retroactively. It moved to fast to get any feedback before.

I'm inclined to stay with the 30a meter, now up on the soi pole and working fine. Mrs. will try to beat them down on the bill, then we move on with life.

Due to this thread however, I will work out what I've got & what our constant and peak power draws are. Suspect it will lead me to decision point on upgrading my line in from the street and possibly the main on the wall in the basement.

When I get my electric notes together, I'll likely ask a few more questions here. My mate from Patts arrives today, he's got exp building a flat block in Thailand and should be able to give me a hand with this part.

Tx and regards,

J

[HAL9000]

Thanks for the explanation

The power calculator mentioned before :

[55Jay]

Thanks for the explanation

Keep in mind each of those breakers feeds a particular area/electrical item in your residence.

Yep, got it, thanks.