Low voltage single phase - whole house stabilizer or get 3 phase and split?

[crs]

On a soi supplied by a transformer that isn't up to the job...

After searching here, found 2 solutions - a voltage stabiliser or switching to 3 phase then splitting to 3x single phase - with some CU work.

Haven't seen a versus/comparison - I'd appreciate opinions...

Thanks.

[Crossy]

I suggest three single-phase units so you get individual regulation.

Have a look at this thread http://www.thaivisa.com/forum/topic/812034-3-phase-single-phase-help-needed-crossy/

[IMHO]

You know you have at least one phase that's low voltage - have you tested the other 2? If they also have the same problem, going to a 3 phase system isn't fixing anything. If you do test and find that one or both of the other phases are OK, just get a sparky to hook your meter up to one of the more healthy ones.

If all phases are low, or likely to be so, just get a single phase voltage stabilizer and suck up an extra 5% or so on your monthly bill

Edited May 12, 2016 by IMHO

[IMHO]

I suggest three single-phase units so you get individual regulation.

Have a look at this thread http://www.thaivisa.com/forum/topic/812034-3-phase-single-phase-help-needed-crossy/

The way I'm reading it, the OP currently has a single phase supply - the question is whether to stabilize that, or try to fix the problem by 'upgrading' to a 3-phase meter/supply/CU.

Edited May 12, 2016 by IMHO

[crs]

All 3 are fairly crap - already switched once. Too many new builds on the soi... Stabilizer then?

EDIT - ah, so you edited... Stabiliser it is then.

Edited May 12, 2016 by crs

[IMHO]

All 3 are fairly crap - already switched once. Too many new builds on the soi... Stabilizer then?

Yep.

3 low voltage phases can't ever give you stable 220v, no matter what you do. A stabilizer gets you instant, reliable results though.

Edited May 12, 2016 by IMHO

[crs]

Any suggestions on what size?

Got, 4x small ac that won't likely ever be on same time. Microwave, Fridge Freezer, Well pump, Fans, TVs, PCs...

Cheers.

[IMHO]

Any suggestions on what size?

Got, 4x small ac that won't likely ever be on same time. Microwave, Fridge Freezer, Well pump, Fans, TVs, PCs...

Cheers.

What size is your meter?

5/15?

15/45?

30/100?

[crs]

15/45.

SafeTcut 63a CU with RCBO - never tripped.

Edited May 12, 2016 by crs

[Crossy]

I suggest three single-phase units so you get individual regulation.

Have a look at this thread http://www.thaivisa.com/forum/topic/812034-3-phase-single-phase-help-needed-crossy/

The way I'm reading it, the OP currently has a single phase supply - the question is whether to stabilize that, or try to fix the problem by 'upgrading' to a 3-phase meter/supply/CU.

Yeah, must be getting old

Looks like an AVR is his solution after the other posts.

[IMHO]

15/45.

SafeTcut 63a CU with RCBO - never tripped.

A 10kVA / 10,000W model ought to do the job based on meter and the loads you've mentioned.

[Crossy]

15/45.

SafeTcut 63a CU with RCBO - never tripped.

A 10kVA / 10,000W model ought to do the job based on meter and the loads you've mentioned.

If you can split the CU so the water heaters are not regulated (no need) that would reduce any stress on a 10kW unit.

[crs]

15/45.

SafeTcut 63a CU with RCBO - never tripped.

A 10kVA / 10,000W model ought to do the job based on meter and the loads you've mentioned.

If you can split the CU so the water heaters are not regulated (no need) that would reduce any stress on a 10kW unit.

Water heaters - meaning electric showers? (2x - forgot)

[bankruatsteve]

You could try to go to your PEA and complain. Especially if you haven't already. Most PEA are pretty good at trying to supply.

[crs]

You could try to go to your PEA and complain. Especially if you haven't already. Most PEA are pretty good at trying to supply.

They are well aware - The PYBaan has been onto them plenty. I've read Crossy say, PEA don't generally have the cash for expansion - guess that's the case. That said, plan to go see them tomorrow - but am not optimistic.

There's been a few new houses on the soi and now apartments and a GH. These businesses are just about built - no way they can meet the kind of power needs they'll have as things are but, apparently, they are unwilling to contribute any more of a share towards a bigger transformer then locals will put in - and the locals really don't have the cash to contribute (though I don't feel like it is their responsibility much anyway). I'm in an old house but have added more appliances - I'm OK to contribute a good size amount towards a transformer - but no way I'll be covering everything for the new 'hiso - attitude' businesses (and their profit making). 'Thainess' at it's best! No idea what they'll actually do when the guests want ac!

Ideally, the new businesses should contribute most, new houses some - and me, the falang with an extravagant 4 small ac, a bit more... The situation is worsened by the fact there is a water problem around the soi area - wells are dry. A deep well has been dug to supply the soi but it needs a good size pump - which will certainly need better electric - before it can be used. I'm getting water truck deliveries to a storage tank to get by - as are others - but that's not a great solution.

[crs]

Anyways, thanks for the help guys.

[Crossy]

Do let us know how you get on with PEA, are you going to take your puyaibaan along to lend some weight?

Whilst it is true they have little available budget, they don't have zero budget, it cannot hurt to ask.

[crs]

The PEA say they are going to do it... But when it'll get done, who knows.

Said there's no way for any contribution or even full payment to speed things up as it's non-private so just have to follow their procedure.

How best to wire in a stabiliser? (I have a SafeTcut CU with RCBO.) Only stabiliser available local are these Chinese rebrands:

Edited May 13, 2016 by crs

[IMHO]

The PEA say they are going to do it... But when it'll get done, who knows.

Said there's no way for any contribution or even full payment to speed things up as it's non-private so just have to follow their procedure.

How best to wire in a stabiliser? (I have a SafeTcut CU with RCBO.) Only stabiliser available local are these Chinese rebrands:

The stabilizer goes between the meter and the CU.

I just looked up some prices, and it seems the 15kva model is only a couple of thousand more than the 10kva one, so maybe that's a better idea as it could run your water heaters as well?

[crs]

These prices for the Comson rebrands: http://www.sahasound.com/AC-DISTRIBUTOR/COMSON and Global House have the Liao (http://www.lioa.com/en/san-pham/ap-ap-1-pha/automatic-voltage-stabilizer-1-phase) at 15KVA for 13900b and 20KVA for 18900b.

[bankruatsteve]

Is stabilizer same as AVR? In any case, what happens if load exceeds capacity?

[Crossy]

Is stabilizer same as AVR? In any case, what happens if load exceeds capacity?

Yes. Overload it and its incoming breaker will open, cutting off the supply and protecting the AVR.

Also, don't forget that a 10kW load on the output @ 220V drawing about 45A will draw nearly 60A on the input side if the supply is down to 170V.

If your incoming breaker is 50A then that's about the limit.

[crs]

Is stabilizer same as AVR? In any case, what happens if load exceeds capacity?

Yes. Overload it and its incoming breaker will open, cutting off the supply and protecting the AVR.

Also, don't forget that a 10kW load on the output @ 220V drawing about 45A will draw nearly 60A on the input side if the supply is down to 170V.

If your incoming breaker is 50A then that's about the limit.

I've got a 63a main breaker CU - with a 15/45 meter. Going to get a 20KVA stabiliser.... Get it wired in between the meter and CU. That sound OK to you, Crossy?

[Crossy]

Yup, a 20kVA unit will supply everything that your current system can.

You will need some kind of isolation between the stabiliser and the incoming supply, as a minimum so you can safely service / replace it.

Do you have a separate Safe-T-Cut unit before the CU? If so putting the stabiliser between the Safe-T-Cut and the CU is simple and practical. Failing that you need an isolator (or a double pole 63A MCB which will be easier to get).

[crs]

Yup, a 20kVA unit will supply everything that your current system can.

You will need some kind of isolation between the stabiliser and the incoming supply, as a minimum so you can safely service / replace it.

Do you have a separate Safe-T-Cut unit before the CU? If so putting the stabiliser between the Safe-T-Cut and the CU is simple and practical. Failing that you need an isolator (or a double pole 63A MCB which will be easier to get).

No, the main breaker is in the CU so will have to isolate it.

EDIT: I've also got a surge protection device waiting to be fitted - put it before or after the MCB? (Before, I guess.)

Edited May 14, 2016 by crs

[Crossy]

If you're going to have to install an isolator put it in a small DIN box and you can put the surge arrestor in the same box

Is your CU a Schneider / Square-D plug-in type, or the more versatile DIN mount type (which you should be able to adjust to avoid needing the isolator).

If not sure please post a photo of it with the lid off.

[crs]

CU is a SafeTcut: http://safetcutgold.com/products9.html

[bankruatsteve]

Just curious why you are choosing 20 KVA when it seems like 10 KVA would be more than adequate even if all the stuff you mentioned is running?

[crs]

IMHO said 10 at first but then said 15 better if including water heaters. 20 not much more then 15 so reason = safety margin.

I'm not sure of the calculation, tbh, but am happy enough to go off both IMHO and Crossy's advice to not feel I need to go research myself. Doubt there's any real downside, apart from initial extra expense.

[bankruatsteve]

OK. Just if you hadn't thought of it and if you have and ammeter, you could turn everything on and measure that then you know for sure what it would take. (or a batch of stuff at a time.) In my experience doing so, I find that things like water heaters don't draw as much as the wattage rating would indicate and things like water pumps draw a lot more than the given wattage. Cheers.