Various house wiring questions...

[Thaipwriter]

Overseeing a new build single story 2 bedroom house build, it's nearly time to start conduit and wiring and I have more questions than answers given there seems to be no code for electrical installation available.

First question is if I have every single wire installed in the whole house fully enclosed in plastic conduit pipe it is ok to use single core THW 1x2.5mm wire throughout as opposed for example 2x2.25mm2 VAF cable?

 

Second question is the earth wire pulled between 3 pins double outlets, best practice is to use green/yellow THW 1x2.5mm2 or will 1x1.5mm2 suffice.

 

Third question relates to RCBO which I see I now "mandatory", the panel I bought came with a 63a 2p RCBO as the main breaker. I will be on a 15/45 meter and suspect I should have ordered a 50A instead, should I change that out now or wait and see if it fails inspection? 

 

Fourth question relates to running a cable outside to the pad where the water pump will sit. It seems on rental houses I've stayed in they are buried VAF 2x1.5mm2 or 2x2.5mm2 in the yellow plastic trunking about 5 inches below grade. This seems a bit dodgy. Is that the accepted thing to do or is there an improved way?

 

Many more questions, but answers to these would be great!

[sometimewoodworker]

35 minutes ago, Thaipwriter said:

there seems to be no code for electrical installation available.

There is a code published in Thai often not respected. @Crossy will have a link

35 minutes ago, Thaipwriter said:

First question is if I have every single wire installed in the whole house fully enclosed in plastic conduit pipe it is ok to use single core THW 1x2.5mm wire throughout

Yes, though you may want a few THW 1x4mm~6mm circuits 

35 minutes ago, Thaipwriter said:

Third question relates to RCBO which I see I now "mandatory", the panel I bought came with a 63a 2p RCBO as the main breaker. I will be on a 15/45 meter and suspect I should have ordered a 50A instead, should I change that out now or wait and see if it fails inspection? 

Leave it in, only change it if asked (you may decide to have a 50A available to swap in)

 

35 minutes ago, Thaipwriter said:

Fourth question relates to running a cable outside to the pad where the water pump will sit. It seems on rental houses I've stayed in they are buried VAF 2x1.5mm2 or 2x2.5mm2 in the yellow plastic trunking about 5 inches below grade. This seems a bit dodgy. Is that the accepted thing to do or is there an improved way?

It is dodgy and against the regulations. Use the correct double insulated cable rated for the job NYY or NYY-G

https://www.bangkokcable.com/system/product/file_upload/211102_450!750V 70C NYY-G_2-4core_Rev04.pdf

Edited April 2 by sometimewoodworker

[Crossy]

OK

THW 2.5mm² on 20A breakers will do the trick for your outlet circuits, run a green or green yellow 2.5mm² for ground.

Run 1.5mm² on 10A breakers for lighting.

 

I'd leave the 63A until it "fails" inspection, if the inspector is friendly, it could be "lubricated" into compliance

 

For your pump you need NYY. Run 2 core if you put in a ground rod at the pump.

 

[Crossy]

The main regulations book you need is "รหัสมาตรฐาน EE 2001-56  มาตรฐานการติดตั้งทางไฟฟ้าสำหรับประเทศไทย พ.ศ. 2556" (Standard EE 2001-56 Electrical Installation Standard for Thailand, 2013). There are associated standards for lightning protection and the like which you probably won't need.

 

Get it here or good bookstores for 225 Baht https://eitstandard.com/มาตรฐานการติดตั้งทางไฟ-2/#

 

As far as I'm aware it is not available in English.

 

Unfortunately, there's not a Thai equivalent of BS7671 or AS3000 which would make life easy. The best we can do is the information published by PEA which is linked in one of the pinned threads.

 

If you want to wire to an English language standard you could do worse than to follow AS3000 (Aussie standard) which would meet or exceed any Thai requirements.

 

[Thaipwriter]

1 hour ago, sometimewoodworker said:

Yes, though you may want a few THW 1x4mm~6mm circuits 

I didn't word that very well sorry, lights 1.5mm, plugs 2.5mm, showers 4mm and so on.

 

1 hour ago, Crossy said:

For your pump you need NYY. Run 2 core if you put in a ground rod at the pump.

Ground rod is next to pump pad. There will be a small pool filter / pump there also so probably run 2x4mm2 NYY in plastic conduit to it.

 

I have three airs cons going in. Two 12,000 btu interters and one 18,000 btu inverter. If I've searched correctly on here they need each have their own 20a breaker with 3x2.5mm2 wiring? 

 

Two showers as yet unknown whether 4000w to max 6000w these need their own 30a breaker and 2x4mm2 + 1x2.5mm2 earth cable?

 

Thanks for answers guys, it's nice to have a clear plan before work starts.

[sometimewoodworker]

37 minutes ago, Thaipwriter said:

There will be a small pool filter / pump there also so probably run 2x4mm2 NYY in plastic conduit to it.

FWIW NYY is rated for direct inground use. Plastic conduit is not required but if used and glued is virtually certain to fill with water. That is a reason to make sure if you use conduit make sure that it is not glued so the water can escape. The conduit can provide a moderate degree of protection from digging tools, so not a bad idea 

[Thaipwriter]

4 minutes ago, sometimewoodworker said:

Plastic conduit is not required but if used and glued is virtually certain to fill with water.

Good to know, maybe I'll just direct bury it and run some plastic "caution / warning "tape just above it in the trench. It'll be about 400mm below grade, I doubt the wife has the energy to dig holes for her plants that deep. 

[KannikaP]

1 hour ago, Thaipwriter said:

I have three airs cons going in. Two 12,000 btu interters and one 18,000 btu inverter. If I've searched correctly on here they need each have their own 20a breaker with 3x2.5mm2 wiring? 

Being a bit thick on electricity numbers, surely a 12000 BTU A/C takes around 1200 watts which at 220volts means 5.5 amps. Why a 20 amp breaker please?

[Crossy]

Just now, KannikaP said:

Being a bit thick on electricity numbers, surely a 12000 BTU A/C takes around 1200 watts which at 220volts means 5.5 amps. Why a 20 amp breaker please?

 

You size the breaker to protect the cable (2.5mm²) and to handle the potential start-up surge from a conventional A/C.

 

Modern inverter units don't have the surge but it never hurts to be future-proof in case your unit isn't big enough.

 

We wired all our A/C locations in 4mm² (on 20A breakers) "just in case" the additional cost was small.

[Thaipwriter]

@Crossy

I saw on another thread you mentioned you used Wago 773 push wire connectors in your house build. I'd like to know if it ok to use three of those in a junction box in the ceiling space above each drop down to each socket on a radial circuit. The Wagos would connect the incoming 3 x2.5mm2 wires to three 2.5mm2 wires that drop down to the socket and also to the three wires that run onwards in the circuit to the next socket outlet, and so on up to a total of 8 double sockets per circuit?  Would that be up to an acceptable standard?

 

[Crossy]

2 minutes ago, Thaipwriter said:

@Crossy

I saw on another thread you mentioned you used Wago 773 push wire connectors in your house build. I'd like to know if it ok to use three of those in a junction box in the ceiling space above each drop down to each socket on a radial circuit. The Wagos would connect the incoming 3 x2.5mm2 wires to three 2.5mm2 wires that drop down to the socket and also to the three wires that run onwards in the circuit to the next socket outlet, and so on up to a total of 8 double sockets per circuit?  Would that be up to an acceptable standard?

 

 

If the whole circuit is in 2.5mm² and on a 20A breaker you'll be fine.

[Thaipwriter]

7 minutes ago, Crossy said:

If the whole circuit is in 2.5mm² and on a 20A breaker you'll be fine.

Yes to both points. Thanks for your help on this thread and also for the many times I've come here for info posted by you since something like 2006!

[sometimewoodworker]

14 hours ago, Thaipwriter said:

@Crossy

I saw on another thread you mentioned you used Wago 773 push wire connectors in your house build. I'd like to know if it ok to use three of those in a junction box in the ceiling space above each drop down to each socket on a radial circuit. The Wagos would connect the incoming 3 x2.5mm2 wires to three 2.5mm2 wires that drop down to the socket and also to the three wires that run onwards in the circuit to the next socket outlet, and so on up to a total of 8 double sockets per circuit?  Would that be up to an acceptable standard?

 

NB there are Wago, copies of Wago, copies of copies of Wago all the way down to items that are not very safe.

The major differentiation is that Wago plastics are heat resistant and self extinguishing as you go down the scale the plastics become less heat resistant and more inflammable.

The majority of the copies along with the genuine Wagos will actually stay connected at significant multiples of the 35A ish current that a 20A breaker will disconnect at, so much so that the insulation will melt off and the connector stays connected, John Ward an English electrician has posted a few interesting videos, as I recall the current he got up to was over 150A and the 2.5mm wire was at least very hot.

this is one of the tests

 

Edited April 11 by sometimewoodworker