Electrical for a brand new house build - questions

[khunPer]

On 8/20/2020 at 6:19 AM, Petey303 said:

I am working on my electrical connection for my house build. What I have gathered from reading around the forum:

• Electric connection - 30/100 amp 3 phase
• Must be grounded

 

I want to have a power plan including Generator and UPS for outages. I know they don't happen much, but I want to ability to run part of the house. So I want to wire the house to be able to have a UPS cut in and just power the electronics, lights, and refrigerators/freezer (maybe pick one or two outlets that stay on).

 

How do I specify this in the drawings? 

What are the common Thai pitfalls I should be aware of?

Electric grounding with proper ground-spikes should be basic practice when building a new house. All outlets, both plugs and for lamps etc. should have a ground wire, furthermore any connection to items in connection with water, like water heaters and pumps, should have an addition protection with RCBO-circuit breaker.

 

It sounds like a quite big house with 3-phase 30A connection, that's about 20kW load in total. I have the same connection to my house, but we never use that much. I chose inverter aircons (have 7 in total), and they are relative cheap in use, also modern TVs and inverter fridge/freezer don't use much power.

 

I planned my electric system with separated circuits, so the emergency light/outlets are totally separated from the main circuit. You would need a switch point between mains and generator, or whatever emergency power you intend to use.

 

For shorter black puts fridge and freezer are not a problem, but if you expect blackout lasting for days, they are. I talk from experience, as the island I live on, once has the major underwater supply cable going kaput, and we were without power for more than three days, apart from one hour ever 18th hour, hardly enough to refill the water tank on the attic.

 

I use a water tank, including a solar heated water system with tank, so even during black out the house has running water for some time – about a day, as it's a 900 liter tank + 200 liter solar heated warm water – the solar heater pre-heats the water for small instant water heaters, which are not running in sunny periods. The solar heater water tank does have a build in electric heater, but it's not connected. The warm water tank is under the roof, so I use a hot-water circulation pump for the solar panel. I chose the Danish Grundfoss central heater circulation pump, which I know from my home country, and it's available in Thailand for around 6,000 baht. It's running on a light sensitive switch in sunny days, and use less than 30 watt power.

 

I use UPS back-up for light and electronics in separate circuits. Even an ordinary 500VA or 1000VA UPS will do a great job, as lamps now works with low energy LEDs, it's merely the battery capacity that matters. I also separated any sensitive electric equipment, such as computers and TVs, so the have an undisturbed power supply, as it's not only the long lasting black outs, but also the short ones lasting seconds only, that can disturb the equipment; furthermore it protects with a stable voltage supply. All UPS circuits ends in a separate machine room (the pump and water-filter room), so it can be connected to whatever source in the future.

 

Today you can plan with larger 220 volt inverter's and efficient battery packs for many emergency purposes, instead of a generator. Furthermore you can charge batteries from both solar energy and from the main supply.

 

When I had my computer drawings for the house printed, I used a number to draw electric circuits, which the architect firm later inserted in the house drawing, doubled checked, and then I looked for an electrician that could understand both my explanation, and the drawings. I had meetings with a couple, and finally found one understanding it, and it actually ended up extremely well.

 

We – the architect and I – used various codes for the different systems, and to explain the connections etc. If it can be any help for you, or your architect, I'll share a few samples hereunder...

 

 

 

 

[khunPer]

On 8/20/2020 at 1:10 PM, sometimewoodworker said:

Like this? ???? 

Makes sense – in the always crystal clear light of hindsight I wish that I had been so foresighted – since my girls got wireless iPay-stuff, the house have never had that many wires everywhere, charging almost everything between Heaven and Earth, except my wallet...

[sometimewoodworker]

6 hours ago, thaibeachlovers said:

On 8/20/2020 at 6:10 PM, sometimewoodworker said:

That's getting near the requirement, but could still do with a few more :-).

I prefer mine higher than the common height, which I can do as I do my own electrical work. Would be good in any Thai house likely to be flooded.

You mean like this

 

or this?

[RocketDog]

If I built a house I would make ALL the wiring surface wiring in ducts. 

 

Anything buried in the walls or floor will fail, especially if it's done in the typical Thai electrical fashion. 

I would do the same with plumbing. 

 

I've spent too much time and money tearing apart walls and floors to repair wiring and plumbing. 

[DJ54]

18 hours ago, Petey303 said:

No well pump

Unless you know the water readily available n regular basis.... if your living

in the countryside could be water shortage issue. We live 1/2 km from main

village... 7-9:00 A.M. low to no water.... Evenings 18-20:00 low to no water. 

Usually the low isn’t enough to wash dishes even a few dishes. 

 

We have the village public ( has shortages  at times) and well w/holding tank..

 

its inexpensive to have well drilled and set-up with pump.. was all included.

the pump is hooked to specific areas...

[sandyf]

On 8/20/2020 at 11:46 AM, Petey303 said:

The house is 360 m2.

 

I like the three zones, I will specify that for the builder. 

 

What do they use to switch over from UPS/Generator? I want the house to run on mains all the time. I "switch in" the UPS or Generator when there is a problem. I did not want to have a UPS in pass through powering the house all the time. And I may only have a generator (no big UPS) and use a small UPS internal on the critical electronics (Internet/WiFi/Cameras).

 

Personally I think you are over thinking it. Shortly after I first came here the company my wife worked for was selling off some 9KVA diesel generators and I thought it would be a good idea to get one. Never actually used it, just started it up every so often to make sure it would run if needed. About a year later we got an offer on it and sold it. When the power does go off it is not really for any great length of time, in 12 years worst we have had was when a transformer blew up and that took them about 8 hours.

All you really need is essential services like fridge/freezers with fans and TV for convenience. You need to bear in mind that if there is an outage, then every chance you will have lost the internet anyway, and that can be overcome using a mobile phone hotspot.

I would suggest you look to solar power to provide a second socket circuit using red sockets and good luck with the build, can be a very stressful time.

[khunPer]

On 8/22/2020 at 12:52 AM, Petey303 said:

No Pool, but would like the option one day

A 16A circuit with RCBO-breaker should normally do it – 3.5kW – however the power needed is depending of the size of the pool, and eventually Jacuzzi-corner.

 

A small pool can often run with a 0.5HP circulation pump, i.e. less than 500W. Middle-sized pool will need a larger pump and filter tank. If me, I would consider two 0.5HP pumps each with filter instead of one bigger pump, as if a pump stops working – that will eventually happen – you are not without circulation and filter during the repair period. Same if you make a large pool, rather two 1HP pumps.

 

A Jacuzzi will normally need one or two, 2HP pumps that could use around 3kW. If you considers the Jacuzzi option you should wire for a larger circuit, for example 20A or 32A; I have 32A for my outdoor Jacuzzi, which runs like a small pool with both a filter circulation and two Jacuzzi-pumps.

 

Don't forget a number of outdoor power outlets for tools or whatever... – "whatever" could among other things be electric hot-pans for terrasse or garden dinner – preferably on a separate circuit/circuits.

 

 

And a hint about aircon(s) and economy...

If you don't cool the entire building down, separate inverter units might be the most cost effective. The modern inverters don't make much noise, so they can be (fairly) close to the room(s). Think of service, you'll need both cleaning and check of cooling liquid, so place the units where they are easy serviable; and if running in daytime a place with shadow.

 

It's worth considering aerated concrete, for example SCG's Q-CON bricks and panels. It's an almost 100 year old Swedish invention, and it really saves money in better insulation. If you wish to avoid visible posts and make double walls, you should consider double Q-CON wall, just with an air gap between; which however with optimal insulation would be filled with mineral wool. Also ceilings in aircon rooms are important to insulate, which can be anything from a thin double-foil with airbobles between the reflective layers. Also make sure to have a reflective foil under the roof tiles; it actually makes a huge difference. You can save a lot in power consumption, and also lifetime of not that hard working aircons – I talk from positive experience here in Thailand, and years of experience in utterly cold Scandinavia, where heating matters a lot more than cooling a room down, especially keeping the heat indoor during winter; so same-same, but different...

 

And taking about roof...

For roof steel and tiles you should also consider a quote from SCG's roof expert team. They make the steel construction from galvanized steel, which brings the weight down and expand the lifetime. They can give you a total quote for steel, tiles, water protection and reflective insulation. I got specified quotations from building constructors, and SCG was cheaper to use. They have travelling work-teams that will come to the local area and do a complete job. I especially got suspicious when I realized how much specialized work is involved, to make a proper rainwater protection; the locals jokes me with that my roof is the only non leaking roof on the island during the rainy season...???? Furthermore they give a five-year warranty on the roof – can one find the building constructor two-three later when a roof begins to leak...

 

Building a private house is often both a big investment and project. We are a number of forum members that has already been through the house building process in Land-of-Smiles, so feel free to ask questions, I'm sure most of the house-masters gladly will share their experience and hints...????

 

[khunPer]

On 8/22/2020 at 6:50 AM, DUNROAMIN said:

3 Phase, Overkill. Man what are you planning for, a factory out the back with heavy machinery. Single phase 60 amp, 2400W generator will almost run the whole house as back up. Install a change over switch from mains to Auxiliary. Install good quality RCBO circuit breaker hub and group your breakers per the load in each area of the house.

I have just about 300 square meter indoor area in my house, and it has 3-phase 30(100)A connection. For a house that size I would not opt for anything but 3-phase – 3-phase 15(45) might do – and separate RCBO-circuit breakers for individual groups, not one only that shuts the whole house down.

 

A house the size op OP's with 4-5 en-suite bedrooms and 6-7 or more aircons would need 20-25+ circuits. I have 37 circuits in my house, with 30 major breakers, and a total of 7 sub-breakers for aircons.

????

[DUNROAMIN]

On 8/22/2020 at 12:00 PM, Crossy said:

 

Have you checked out his floor plans? There's >96,000 BTUs worth of airconditioned space.

 

He MAY be able to get a single-phase 30-100 meter, which would support the calculated load (but probably not his electic range), depending upon where he is, but a 15-45 single-phase won't support his prospective load.

 

A 15-45 3-phase really is going to be his best bet.

[DUNROAMIN]

On 8/23/2020 at 2:01 PM, khunPer said:

I have just about 300 square meter indoor area in my house, and it has 3-phase 30(100)A connection. For a house that size I would not opt for anything but 3-phase – 3-phase 15(45) might do – and separate RCBO-circuit breakers for individual groups, not one only that shuts the whole house down.

 

A house the size op OP's with 4-5 en-suite bedrooms and 6-7 or more aircons would need 20-25+ circuits. I have 37 circuits in my house, with 30 major breakers, and a total of 7 sub-breakers for aircons.

????

[thailand49]

I don't know <deleted> about electrical but one thing I do know living here have them put more than one plug in the room I'm tired of all the electrical extension cords that constantly go bad! 

[Crossy]

1 minute ago, thailand49 said:

I don't know <deleted> about electrical but one thing I do know living here have them put more than one plug in the room I'm tired of all the electrical extension cords that constantly go bad! 

 

Indeed, but see post #11 ????

 

[Harry Fingerling]

Work out your current demand first and four most and go from there. 

[Petey303]

On 8/20/2020 at 1:30 AM, bankruatsteve said:

As mentioned you could have a CU per as many zones as you like and still use single phase entrance.

Pushing in to the zones and finding I have some more questions. 

 

On 8/20/2020 at 1:51 AM, jojothai said:

Yes, why would 3 phase be necessary, it brings you other potential problems of having the three separate supply zones.

If i am interpreting what crossy said was suggesting is three different types of supply categories that i presume could be in each zone.

If so, i think you need to be careful working out how many boards and circuits you will need for safety if using 3 phase. 

Somebody else may understand this better to add comment

Questions:

To do the zones, are the zones separated per phase and run a single phase generator to keep one phase alive?

 

Or, do you do the zones per the breaker panel, open two breakers, hook up the 3-phase generator and run?

 

Any high level schematics someone could recommend?

 

[Crossy]

Use this as a starting point, it's basically what we have without the EV charge point, yet (Madam has decreed that our next new vehicle will be all electric).

 

If you have 3-phase distribute the load across the phases to keep things roughly balanced.

 

If possible avoid 3-phase appliances**

 

Nothing to stop you using a small single-phase genset and running one phase of "essential", you must still install a 3-phase transfer switch just don't connect two of the genset input phases (and you can upgrade to a bigger 3-phase genset later).

 

Install earth-leakage protection, either in split-service distribution boards or as individual RCBOs on "risky" circuits (water heaters, outdoor lighting and outlets, kitchen outlets [but keep an unprotected circuit for the freezer]).

 

** The reasoning is that most power failures are loss of a single phase, 3-phase appliances really don't like this and you may need to make arrangements for phase-loss protection.

 

There is no reason to be wary of 3-phase, the voltage to earth is the same 220V as your single-phase supply so any single-point shock will be just the same. To get the even more lethal 380V shock you need to touch two of the phases! 

 

EDIT Have you considered where you are going to put your electrical stuff, it's not usually aeasthetically pleasing so a room to itself is best (Yes, ours is in the lounge!).

 

Also consider if flooding is a possibility, our distribution panels are upstairs and all downstairs outlets are 1.5m above floor level (yes, we have a flood risk).

 

[Petey303]

4 hours ago, Crossy said:

EDIT Have you considered where you are going to put your electrical stuff, it's not usually aeasthetically pleasing so a room to itself is best (Yes, ours is in the lounge!).

Electrical stuff is going under the stairs with fan exhaust. Panel is going in the garage. No flooding where we are.

 

4 hours ago, Crossy said:

Use this as a starting point, it's basically what we have

I went through a post of yours where you built your own solar, I am planning on following the spirit of that plan after my house is done. I do want to wire in what I can now for the solar panels.

 

In your diagram, I do not see how your solar panels are tied in. In the domestic distribution board, is there something that lets current flow back, or the solar can only power the stuff on that leg?

 

When you say distribution board, that is what I would call a breaker box. You have two physically separate breaker boxes at your house?

[Crossy]

1 hour ago, Petey303 said:

In your diagram, I do not see how your solar panels are tied in. In the domestic distribution board, is there something that lets current flow back, or the solar can only power the stuff on that leg?

 

When you say distribution board, that is what I would call a breaker box. You have two physically separate breaker boxes at your house?

 

The solar panels feed an inverter, the inverter connects to a regular 2-pole MCB in the "domestic" board, the inverter takes care of generating enough voltage to feed into the supply (and out into the wide world if you are generating more than the house is using).

 

We actually have 5 boxes (in UK speak "Consumer Units") but our system has evolved somewhat from what was originally designed. If I were doing it again it would fit in 3 boxes.

[KKr]

On 8/20/2020 at 3:38 PM, thaibeachlovers said:

While it's not exactly what you wanted to know, take the number of power outlets you plan for and double the number. Most of us never have enough power outlets once we buy all the electrical junk toys we want.

I usually put a three wire i.e. earthed double outlet every two meters in the house,
with extra in the kitchen, home-office (think: comp(s)/HDD(s)/printer/scanner/shredder/modem/fibre-optic connecter/phone charger(s)/camera kit/TV with decoder, DVD player or the like / reading lamps/ceiling lights/ceiling fan/ ), and heavy duty in the hobby room of course.
And, when it is a newly build, at the same time pull WAN internet, also to TV(s), plus TV antenna (at least two coax if you use satellite) and loudspeaker cables to each room.
Also, do not forget the patio a really strong cable for electric grill, and whatever tools you are using.
Waterpump and filter pumps on separate group.
and electric gate opener for what a waterproof cable is usually more recommendable than the three wires (or four/five if manual switch) in a plastic pipe.

Edited August 25, 2020 by KKr

[Petey303]

 

Quote

 

Posted 28 minutes ago

  2 hours ago, Petey303 said:

In your diagram, I do not see how your solar panels are tied in. In the domestic distribution board, is there something that lets current flow back, or the solar can only power the stuff on that leg?

 

When you say distribution board, that is what I would call a breaker box. You have two physically separate breaker boxes at your house?

 

The solar panels feed an inverter, the inverter connects to a regular 2-pole MCB in the "domestic" board, the inverter takes care of generating enough voltage to feed into the supply (and out into the wide world if you are generating more than the house is using).

 

Understood, but is the drawing missing something? Where do you isolate the solar panels from the grid? There is usually some diodes so you don't drive the mains when it is down. Maybe this is a USA thing and not done in Thailand? 

 

Thanks for all the help, this is really helping me get my plan straight.

 

[Crossy]

1 minute ago, Petey303 said:

There is usually some diodes so you don't drive the mains when it is down. Maybe this is a USA thing and not done in Thailand? 

 

It's called "island protection" and is built into the inverter. I've not seen a domestic level grid-tie inverter without it built in.

 

If you want your solar to act as a UPS when the mains is off you will need a hybrid inverter ($$$) and batteries (more $$$).

 

 

[Petey303]

1 minute ago, Crossy said:

 

It's called "island protection" and is built into the inverter. I've not seen a domestic level grid-tie inverter without it built in.

 

If you want your solar to act as a UPS when the mains is off you will need a hybrid inverter ($$$) and batteries (more $$$).

Got it - Thanks

[sometimewoodworker]

21 minutes ago, KKr said:

I usually put a three wire i.e. earthed double outlet every two meters in the house,

IMNSHO that is way too few, all you need is a piece of furniture that fits in front of your socket and you will need spiders. Admittedly the wall I showed could do with fewer, that one is overkill, but the cost of adding them when building is quite small and the convenience is great.

[KKr]

On 8/25/2020 at 2:12 PM, sometimewoodworker said:

IMNSHO that is way too few, all you need is a piece of furniture that fits in front of your socket and you will need spiders. Admittedly the wall I showed could do with fewer, that one is overkill, but the cost of adding them when building is quite small and the convenience is great.

you got the idea.
put the TV Cabinet between Washing Machine and Fridge and Bob's your uncle !