Help me design my electrics

[reflectionx]

Someone lost in the Thai ways of doing things needs your expertise.

We are buying a new house, and the builder has already installed the wires, apparently done the "Thai way" - no conduits and, I suppose, tape. He has no idea how to run the wires in conduits (asked me for pictures,lol) After some discussion, he agreed to redo the wiring to satisfy some minimal requirements. Currently, the circuit is single phase 15/45. He said that he built every other house in the area this way, but that's no reason to put my family at risk and have potential issues in the future.

I am an amateur when it comes to electricity, so I need some guidance here. At here we are not allowed to do our own wiring, must be done by electrician, so I don't know much about the matter, just general knowledge.

First, I need to figure out what questions to ask to get the picture before asking him to start changing things. I am trying to be reasonable with the builder and not make him to do unnecessary changes.

Maybe I could live with the wires run in the wall,not in conduits, but I won't compromise anything related to safety.

We have 4 bedrooms, 3 bathrooms, living room and a kitchen. For now, we will have 2 ACs only, but in the future the number will probably grow to 4-5 units. The remaining is the normal stuff - stove, fridge, washer, etc ... We have not decided on appliances yet, so I cannot do the math for the wire gauge, but it will be the normal stuff (pretty standard) .We don't have swimming pool. For now, there is no water pump, but if we have pressure problems, we might end up installing one. Also, for now we plan to use 2Kw tank water heater, but we might end up using tankless in the future (one heater for the entire house, so it might have high A?).

I guess before I begin I decide whether I need 3 phase or single phase. What are the pros and the cons? Which one cost more in terms of monthly bill?

Next, I am not sure what questions I should begin with. From what I've read, I need to ask about

- wire gauges

- ELCB (on which circuits vs RCBO, e.g. fridge circuit should be ELCB?)

- RCBO (preferably on individual circuits, not one central)

- grounding (on each circuit?)

What exactly do I check to ask about these items?

Anything else missing from the list?

Thanks a bunch!

[Crossy]

What exactly do I check to ask about these items?

Anything else missing from the list?

Task 1, has he / is he going to install grounded outlets and run ground wires?

Task 2, has he / is he going to install grounded outlets and run ground wires?

If the answer to 1 or 2 is no and combined with his lack of knowledge regarding conduit, change your sparks.

Have a look on these pages for some inspiration http://www.crossy.co.uk/wiring/

A 15/45 meter is good for a max demand of about 11kW with short peaks to 15 or so.

With 5 aircons you'll probably be OK (they likely won't all be running at once) but if you add a big tankless water heater you're into 3-phase territory.

If you're going that way check that it's available in your street, otherwise you'll be in for more expense.

EDIT Before you bite the 3-phase bullet, check with your local MEA/PEA office if you can have a 30/100 single phase meter which will likely be enough provided you don't go too mad on the tankless heater.

[reflectionx]

What exactly do I check to ask about these items?

Anything else missing from the list?

Task 1, has he / is he going to install grounded outlets and run ground wires?

Task 2, has he / is he going to install grounded outlets and run ground wires?

If the answer to 1 or 2 is no and combined with his lack of knowledge regarding conduit, change your sparks.

Have a look on these pages for some inspiration http://www.crossy.co.uk/wiring/

A 15/45 meter is good for a max demand of about 11kW with short peaks to 15 or so.

With 5 aircons you'll probably be OK (they likely won't all be running at once) but if you add a big tankless water heater you're into 3-phase territory.

If you're going that way check that it's available in your street, otherwise you'll be in for more expense.

EDIT Before you bite the 3-phase bullet, check with your local MEA/PEA office if you can have a 30/100 single phase meter which will likely be enough provided you don't go too mad on the tankless heater.

I know that the 3 phase is available, since they installed it in only one house (out of 80-ish) in the development, but the question is if I really need it. I am not sure how used they are on running 3 phases, so it might end up doing more harm than good. I will check on the 30/100 meter.

I looked at your website, lots of good info. I have a question though. Isn't it better to get a RCBO on each circuit instead of one ELCB for all circuits?

[Crossy]

I looked at your website, lots of good info. I have a question though. Isn't it better to get a RCBO on each circuit instead of one ELCB for all circuits?

Using individual RCBOs reduces the possibility of nuisance trips, in reality it's all down to cost.

As RCBOs become cheaper using individual units becomes practical.

By the way, the modern term is RCD or RCCB not ELCB, ELCB is reserved for the old voltage-operated (and unreliable) units.

If you treat your 3-phase installation as three single-phase installations (no actual 3-phase appliances apart from maybe a big water heater), you'll get the added advantage of keeping some power in the event of the loss of up to two of the phases.

[doglover]

Maybe I could live with the wires run in the wall, not in conduits, but I won't compromise anything related to safety.

Are the wires run in the wall or on the wall?

I'll assume in the wall as that is what you stated. So are they run free air in a cavity with a dual wall system? Or did your electrician worker cut a groove in the wall and somehow secure the wires in the groove and then render?

The former would surprise me as I don't believe any 'developments' use a dual wall system. If the latter, bizarre.

[Artisi]

I looked at your website, lots of good info. I have a question though. Isn't it better to get a RCBO on each circuit instead of one ELCB for all circuits?

Using individual RCBOs reduces the possibility of nuisance trips, in reality it's all down to cost.

As RCBOs become cheaper using individual units becomes practical.

By the way, the modern term is RCD or RCCB not ELCB, ELCB is reserved for the old voltage-operated (and unreliable) units.

If you treat your 3-phase installation as three single-phase installations (no actual 3-phase appliances apart from maybe a big water heater), you'll get the added advantage of keeping some power in the event of the loss of up to two of the phases.

This is a very valid point re having some power in the house if 1 or 2 phases go out. My sparkie split and balanced the 3 phases over the house which can in handy just a few weeks back on a very hot humid night, we lost power in some parts of the house but was able function quite well with some lights and a couple of a/c units still operative.

[doglover]

^^^^ & Crossy.

Cool. That would be very convenient and I see it mentioned many times about the definite advantage of having 3 phase when only 1 or 2 phases have been dropped.

I am curious if it is worth the extra expense in the long run. Is it a frequent occurrence that only 1 or 2 phases is dropped or would the majority of the time all 3 phases be dropped?

Can someone give a ball park percentage of the chances that during an outage 1 or 2 phases will still be live?

EDIT - I know in our village, most times, when the power is lost it's across the board.

Edited June 26, 2013 by doglover

[Crossy]

Naam is your man regarding 3-phase effectiveness.

We have single-phase and on several occasions we have been without power when next door (on a different phase) are still on, a lot depends on your location I'm afraid.

[reflectionx]

Ok, we are starting the whole thing from scratch. I need to come up with design, list of the non-standard (non-Thai style) materials (connectors, pipes, j-boxes, panel (with RCBOs)).

Thinking of the 3 phases option, I read (even here above) that splitting the phases is a good option. Now what? LOL

[IMHO]

For a start, you don't need to find a "non Thai style" electrician, you just need to find an *actual* electrician LOL.

No need for you to take on all the responsibility for the re-design if you do that first

[reflectionx]

For a start, you don't need to find a "non Thai style" electrician, you just need to find an *actual* electrician LOL.

No need for you to take on all the responsibility for the re-design if you do that first

Fair enough, but statistically speaking, I have more chances hitting the $60 million jackpot. Heck, I could not even find an "actual" plumber that could do the simple job of welding PPR pipes (I was lucky to discover this German guy who sells the PE-RT pipe that I will install myself !)

[Crossy]

Task A is to get a large printout of your floor plan and position your lights, outlets, water heaters and aircons on it.

Then split into circuits (which outlets / lights on each breaker), if you're going for 3-phase make at least three lighting and three outlet circuits (just write a circuit number next to each outlet/light).

Limit to 5-10 double outlets on a circuit, the lighting shouldn't be an issue but split upstairs and downstairs if you want. I would put two outlet circuits to the kitchen plus a separate circuit for an oven / hob.

Aircons and water heaters should go on their own individual circuits.

Then divvy up the circuits between the 3 phases try to keep the loads roughly equal but it's not a disaster if you don't. Don't forget to mix the phases in each lighting area so that you don't lose all the lights in one part of the house if you lose a phase.

Do you intend doing all the wiring and conduit installation yourself? You'll need an assistant, maybe your local sparks.

[reflectionx]

Task A is to get a large printout of your floor plan and position your lights, outlets, water heaters and aircons on it.

Then split into circuits (which outlets / lights on each breaker), if you're going for 3-phase make at least three lighting and three outlet circuits (just write a circuit number next to each outlet/light).

Limit to 5-10 double outlets on a circuit, the lighting shouldn't be an issue but split upstairs and downstairs if you want. I would put two outlet circuits to the kitchen plus a separate circuit for an oven / hob.

Aircons and water heaters should go on their own individual circuits.

Then divvy up the circuits between the 3 phases try to keep the loads roughly equal but it's not a disaster if you don't. Don't forget to mix the phases in each lighting area so that you don't lose all the lights in one part of the house if you lose a phase.

Do you intend doing all the wiring and conduit installation yourself? You'll need an assistant, maybe your local sparks.

thanks, good starting point. Will def look for a local sparkie, I will be overseeing his work. First thing I wanted to know is what requirements I should state (which you listed above).

The next thing I need to know is what to look for during the install. I can calculate wire gauge and amps to see if it will match his calcs, but I have no idea how to check if the grounding will be done properly. What would be the best practice for grounding?

On a side note, are there extra monthly charges for 3 phases vs single phase?

[IMHO]

For a start, you don't need to find a "non Thai style" electrician, you just need to find an *actual* electrician LOL.

No need for you to take on all the responsibility for the re-design if you do that first

Fair enough, but statistically speaking, I have more chances hitting the $60 million jackpot. Heck, I could not even find an "actual" plumber that could do the simple job of welding PPR pipes (I was lucky to discover this German guy who sells the PE-RT pipe that I will install myself !)

Go down to your local PEA and ask them to refer you to an electrician - all will have several current/ex employees they could put you in contact with - and all will be actually qualified electrical engineers.

[reflectionx]

Ok, they sent me a photo of the panel in the only house in the area (out 80-ish he has built) equiped with 3 phases:

Does this make sense?

[Crossy]

I see no RCD!

You'll likely need a bigger panel to handle all your circuits, but that's the sort of thing.