Electrical Loading Can I Add More ?

[Nickthegreek]

I currently have a 45/15 amp thai meter..I run an internet shop with 3 airs cons..27,000/18/000,9/000 btus..34 coms all diskless using 500 watt powers supplies and 2 servers..monitors are 23 inch and 19 inch,2 routers,1 x cctv system

1x coke fridge and lighting all low watt bulbs energy save..

Can anyone tell me if I could get another 10 coms and 1 9000 btu air on thge same circuit without going three phase.

Thanks

Edited February 2, 2012 by Nickthegreek

[sezze]

Peak load is now allready way too much . I guess you do need a upgrade to higher meter .

[Crossy]

At first sight you're likely pushing things but why not check what you are actually using, it may well be a lot less than you think.

Go and buy or borrow a clamp type amp meter and stick it over your live incoming cable. If you can get a meter with peak hold so much the better so you can check for the actual maximum load.

Fire up everything you would normally use and check what you are actually using.

Whilst you're at it check one of the computers (you'll have to split out a cable so you just clamp the live), despite the fact they have 500W power supplies they will actually be using nothing like that.

A 9k A/C will use about 5A when running so add that plus 9x whatever the computer is using and you'll have your answer. If it goes anywhere near 45-50A you'll need a supply upgrade.

EDIT

Alternatively and cheaper (free) you can use your electricity meter. During a normal operating period observe your meter and count how many times the disc goes round in 5 minutes. Note the calibration factor of your meter (R/kWH) and then we can work out your average consumption.

[Naam]

i was always suspicious concerning "Thai 15/45" but then i'm not an expert and just used to my home country's "15 = 15" and "45 = 45".

therefore my question Crossy: can one really draw continously and without any problems 45amps when it says "15/45" or does this mean "temporary peak load = 45"?

[4evermaat]

.........

EDIT

Alternatively and cheaper (free) you can use your electricity meter. During a normal operating period observe your meter and count how many times the disc goes round in 5 minutes. Note the calibration factor of your meter (R/kWH) and then we can work out your average consumption.

When you say disk, you mean the KWatt counter itself? Or there is a moving disk somewhere that is observable?

"2nd best time to plant a tree is today." Sent from ThaiVisa app.

[Crossy]

i was always suspicious concerning "Thai 15/45" but then i'm not an expert and just used to my home country's "15 = 15" and "45 = 45".

therefore my question Crossy: can one really draw continously and without any problems 45amps when it says "15/45" or does this mean "temporary peak load = 45"?

Yes, you can pull 45A continuously. The first figure is the calibration current at which the meter achieves its stated accuracy, the second is the maximum rated current.

Whilst you should not normally exceed the rated current, in practice these meters are incredibly robust and won't blink at a short term 100% overload (90A on a 15/45).

When you say disk, you mean the KWatt counter itself? Or there is a moving disk somewhere that is observable?

Below the digits there is an aluminium rotating disk, it usually has a mark on it so you can see it rotating. If you have an electronic meter (unusual in Thailand) there will be a flashing lamp or annunciator on the display which can be used for the same purpose.

[Nickthegreek]

At first sight you're likely pushing things but why not check what you are actually using, it may well be a lot less than you think.

Go and buy or borrow a clamp type amp meter and stick it over your live incoming cable. If you can get a meter with peak hold so much the better so you can check for the actual maximum load.

Fire up everything you would normally use and check what you are actually using.

Whilst you're at it check one of the computers (you'll have to split out a cable so you just clamp the live), despite the fact they have 500W power supplies they will actually be using nothing like that.

A 9k A/C will use about 5A when running so add that plus 9x whatever the computer is using and you'll have your answer. If it goes anywhere near 45-50A you'll need a supply upgrade.

EDIT

Alternatively and cheaper (free) you can use your electricity meter. During a normal operating period observe your meter and count how many times the disc goes round in 5 minutes. Note the calibration factor of your meter (R/kWH) and then we can work out your average consumption.

Crossy,

Thanks,this seems a very simple check for me to complete..A Thai electrician has told me I need an upgrade,but I want to check first and this sounds like it will at least allow me to check before I throw 30,000 baht at an upgrade that may not be required.

Nick

[Crossy]

Crossy,

Thanks,this seems a very simple check for me to complete..A Thai electrician has told me I need an upgrade,but I want to check first and this sounds like it will at least allow me to check before I throw 30,000 baht at an upgrade that may not be required.

Nick

Nick you may want to repeat the check with all your aircons set to 18C to make sure they're running at the same time. If you turn them all off you can also check consumption of your IT kit to get an idea what the extra PCs will use.

Just post the figures here and I'll bash the numbers.

EDIT Whilst we're waiting:-

54000 BTU of A/C will draw about 23A, a further 9000 will add a further 5A = total of 28A on A/C

So if you can get your total of 46 PCs below 80W each you'll be OK, unlikely even if they're diskless

Check if you can upgrade to a 30/100 supply, it will be cheaper than having to go to 3-phase.

[PattayaParent]

Check if you can upgrade to a 30/100 supply, it will be cheaper than having to go to 3-phase.

How would it be possible to change from a 1-phase supply to a 3-phase supply?

(I ask because I may face this problem and have been told it can't be done)

and would a new meter need a bigger supply cable?

Edited February 3, 2012 by PattayaParent

[Crossy]

PP

It depends whether 3-phase is actually available on your pole, if it is then the supply upgrade is no issue. What you will then need to do is install a new distribution board to divide your load amongst the 3 phases. It's not a simple job unless for example you are adding another building which can use one of the new phases but it's certainly not impossible.

If he gets a 30/100 MEA/PEA will likely insist that he upgrades his incoming cable to 25mm, but that will be far cheaper than starting to muck about with 3-phase.

[bankruatsteve]

Maybe should be a new post - but it just blows my mind that 3-phase would be required for domestic use vs "30/100" single. To me, it's what the grid can supply and, if they can adaquetly supply the 100a then why would anybody need 3-phase?

[Nickthegreek]

Crossy,

Thanks,this seems a very simple check for me to complete..A Thai electrician has told me I need an upgrade,but I want to check first and this sounds like it will at least allow me to check before I throw 30,000 baht at an upgrade that may not be required.

Nick

Nick you may want to repeat the check with all your aircons set to 18C to make sure they're running at the same time. If you turn them all off you can also check consumption of your IT kit to get an idea what the extra PCs will use.

Just post the figures here and I'll bash the numbers.

EDIT Whilst we're waiting:-

54000 BTU of A/C will draw about 23A, a further 9000 will add a further 5A = total of 28A on A/C

So if you can get your total of 46 PCs below 80W each you'll be OK, unlikely even if they're diskless

Check if you can upgrade to a 30/100 supply, it will be cheaper than having to go to 3-phase.

Crossy,

Thanks so much,I am sure I can move it to a 30/100 as I think thats available,however, I thought that was three phase,maybe lost a little in translation.! I am assuming this would only require a breaker upgrade to 100 amps and cable from the outside lines to the box? and I would not expect that to cost the 30,000 baht the electrician has mentioned.!

Thanks Nick

[Nickthegreek]

Maybe should be a new post - but it just blows my mind that 3-phase would be required for domestic use vs "30/100" single. To me, it's what the grid can supply and, if they can adaquetly supply the 100a then why would anybody need 3-phase?

Hi bankruatsteve,

Sorry I could not find anywehere else to put the post that would fall on the experts in these forums, this is for a business,sorry for any confusion.

Nick

[PattayaParent]

PP

It depends whether 3-phase is actually available on your pole, if it is then the supply upgrade is no issue. What you will then need to do is install a new distribution board to divide your load amongst the 3 phases. It's not a simple job unless for example you are adding another building which can use one of the new phases but it's certainly not impossible.

If he gets a 30/100 MEA/PEA will likely insist that he upgrades his incoming cable to 25mm, but that will be far cheaper than starting to muck about with 3-phase.

Thanks Crossy, the 3-phase will not be available from the pole, it's for a new build so I'll look at getting a 30/100 upgrade as I'm adding a lot of electrics that are not shown on the basic design.

[Crossy]

Thanks Crossy, the 3-phase will not be available from the pole, it's for a new build so I'll look at getting a 30/100 upgrade as I'm adding a lot of electrics that are not shown on the basic design.

As it's a new build I would future-proof it and design for 3-phase inside the house, it won't cost a lot more, then wire it to your single phase supply. If in the future 3-phase becomes available and your load is stretching the current supply the upgrade will be very simple.

[Crossy]

Maybe should be a new post - but it just blows my mind that 3-phase would be required for domestic use vs "30/100" single. To me, it's what the grid can supply and, if they can adaquetly supply the 100a then why would anybody need 3-phase?

The limiting factor is the local distribution system, particularly if you're out in the boonies

Many villages are populated with homes that have 5/15 meters that are actually drawing nearer 5 than 15. Then along comes one of us with a home that draws more power than the rest of the village put together. A 30/100 (or sometimes even a 15/45) may not be available and the only option without paying for a new transformer is 5/15 or hopefully 15/45 3-phase

[Naam]

Maybe should be a new post - but it just blows my mind that 3-phase would be required for domestic use vs "30/100" single. To me, it's what the grid can supply and, if they can adaquetly supply the 100a then why would anybody need 3-phase?

because if your single phase supply goes you poke your nose while sweating in the dark. with a three-phase connection strategically spread you will still have lights, airconditioning and live power outlets in some areas of the house even if two of the three phases fail.

[bankruatsteve]

Maybe should be a new post - but it just blows my mind that 3-phase would be required for domestic use vs "30/100" single. To me, it's what the grid can supply and, if they can adaquetly supply the 100a then why would anybody need 3-phase?

Hi bankruatsteve,

Sorry I could not find anywehere else to put the post that would fall on the experts in these forums, this is for a business,sorry for any confusion.

Nick

Cheers Nick, I was not talking about your post but mine within your post. Anyway, perhaps I should have said "non-industrial" vs domestic. I don't view your requirement as industrial and I don't agree that it should need 3-phase. The thing is, if you have 3-phase then YOU need to distribute the load or you pay for it. I haven't googled this, but that's got to be the case. In my experience, I was the first to have 30/100 in my village and when I amped up, it caused brown outs. Eventually, the PEA re-distrubuted the load or what - I don't know - but now it's OK. And, while it happens, it's rare for 1-2 of a 3-phase to go down.

[haveaniceday]

I have a quick question for those more electrically minded than me.

In a 4mm wire to a hot water heater, I am putting in a 25A breaker switch. It is connected to a 32A CB in the distribution panel, I can not find a 25A CB that fits in the box.

Does it mater where in the line to the bathroom the 25A breaker switch is actually located to work the same?

What I mean, it is better to have it near the distribution box, or the hot water heater or just any where on the wire ? I do not know if it is looking 'down stream' of it only when measuring the load.

Other considerations, why I would like to put it near the distribution box is bathrooms get hot and steamy and if it is in another room, much harder for it to be constantly reset.

[Crossy]

HND.

What is the intended purpose of the 25A breaker switch? Is it to:-

1. Protect the 4mm cable from overload.
   
2. Provide local isolation for the water heater.
   
3. Something else.
   

If 1. and your heater is the only equipment on the line and it does not exceed 6kW then don't bother.

This is one of those exceptions that demonstrates the rule. There is no possibility of overload (the heater is a fixed load), the 32A will adequately protect the cable from a short circuit and your RCD will open in the event of a L-E fault. You should really verify by calculation that a short at the far end of the run will open the 32A breaker in 0.4 seconds, but in reality unless you have very long cable (in which case volt drop will cause your heater to under perform) there is no need.

If 2. put it outside the bathroom.

If 3. better let us know what its intended purpose is.

[haveaniceday]

I was bought it just trying to protect the wire from overload, I had jotted some notes down from this thread below...

The wire length is short, less than 10m, probably only 7m.

I was planing to put in a 4500W heater, but they only had 6000W in stock of the brand I wanted, so I grabbed that. In looking at some of Crossy other notes, it does may seem over kill. I was not looking to isolate the hot water heater as such, I can do that with a CB in the distribution board, I was thinking, if the switch breaker pops, better to keep it away from egar resetting fingers. (In mum in laws place, after having a heater put in, it regularly tripped the breaker switch with the heater temp on high, in law solution was use a tooth brush and tape to force the breaker open permantly.)

[Crossy]

If you already have the breaker stick it high up outside the bathroom, it can also act as an emergency isolator, or just leave it in your bits box, I'm sure it will find a use soon enough

As I noted above, as you have a fixed load that is within the cable's rating there is no need for overload protection, just short circuit protection, and on a 7m cable that will easily be provided by the 35A breaker. Being a great advocate of KISS I don't normally mention this as it can serve to cause confusion and could lead to an unsafe situation if misinterpreted.

It's important to realise that a small overload, or even a short-term big overload, won't immediately result in conflagration and death. I have on occasion put 35A down a length of 2.5mm, gets pretty warm, but nowhere near starting a fire (not too hot to touch). The big fire starter is poor joints that do get very hot.

[cliffbu]

Hi I tried to start new topic but I received always errors.

Somebdoy know why I cannot start new topic I would like to open internetshop and seek advice