House Electrical Wiring

[TigertheCat]

What would be the best and safest house wiring on a new construction.In UK its multi earth and ring main but here seems to be radial and also here no copper pipes fpr earth.Should I go for a single 2M copper rod or multiple rods and radial or ring.Any electricians out there are very welcome to comment

[OZEMADE]

As it is a new construction, use 3 phase wiring threaded through plastic pipe. Use a single copper rod with the earth running from your power box, which should be a safety switch box. Make sure you have your hot water heater in the shower earthed properly. Hope this was of help.

[dddave]

Thais' are really casual about grounding anything and rely too much on ground fault circuit breakers.

My builder thought I was "ting-tong" as I personally pounded in the ground pipes and I nearly had to pound the electrician ("Electrician"?? what a joke!) as well to get him to properly connect them.

I made sure I was there for every inch of wiring and every connection. I double tested every outlet, switch and wired in device.

Cost me a bottle of Thai whiskey to get him to let me do it my way.

[powderpuff]

Not 3 phase wiring , but 3 WIRE , Live Neutral & Ground.

Crossy will pop in here soon but we basically run "zone" wiring. Figure out how many zones you want. Then source breaker boxes to suit. The newer Square D now known as Schneider are 10 circuit.

Prolly need 2 of those. I circuit for each air con, one for the stove, hot water heaters, clothes dryer, water pump, lights & sockets.

Thai standard is 2.5 mm for a run of sockets but experiece has taught me to go one size larger i.e. 4 mm. This may be overkill. Run 6 mm for aircons. Source a safety-cut of the suitable amperage; 60 amp or 100 amp.

Most likely you will end up with multiple zones of sockets.

I have dedicated circuits for my hi-fi, home theater etcDon't over ground. 1 or 2 are sufficient. Gang them all together. source a roll of 1.5 mm green wire (100 m) for this job.

More curcuits the better. If you get a problem in one zone

Just ask - we are here to help.

[citizen33]

We had an interesting discussion on this forum a while ago about radial circuits versus rings, and I think Crossy probably won the argument when he came down on the radials side. Both these options involve using earth cabling along with live and neutral (not the same as three phase). As I recall, the main advantages claimed for radials were that they are more familiar to Thais and so less likely to lead to mistakes, and because they are cheaper to put in. The other strong point that Crossy made was that it is dangerous to use the UK standard ring protected with a 32 amp breaker, while not also using UK-style fused plugs, because in a fault condition a small appliance not protected by a fuse could be exposed to a lot of current. The temptation is to use Thai-style 3-pin sockets and un-fused plugs, which is what I had done. Actually on checking I was less guilty with my ring main than might have been the case because I was only using 20 amp breakers, but this is an important point. Whatever you do you should not combine half of one system with half of another without being sure that safety features still work. Ring mains appealed to me (a) because you can do longer cable runs without voltage drop (and possible danger in appliances) than is possible in radials (b ) because there is earth continuity redundancy in the event that a cable breaks since you have a connection via both sides of the ring, and (c ) you use fewer breakers in the consumer unit with the longer cable runs possible with rings (and I have 10 already). I think there are people on both sides of the argument, but I guess the point about locals not understanding rings is a big disadvantage.

Edited February 2, 2010 by citizen33

[stgrhe]

1. If your system is 3-phase you should first make a proper balance calculation in order to distribute the load as evenly as possible. In such a case ensure that the live cables has different colours for the R, S and T-phases respectively.

2. The main circuit breaker (MCCB) should be selected according to you maximum load and for that you should do a maximum demand calculation. I suppose the best standards for Thailand is the Australian/New Zealand standard ASNZ 3000 as it is based om IEC but adopted to a more tropical climate than Europe. You can't do better than that for Thailand.

3. Use residual current breakers (RCD), or even better residual current breaker with overload protection (RCBO), for each circuit together with a proper earthing.

4. The cable sizes (core area) for each circuit should be according to the load and Crossby has given a useful rule-of-thumb on one of his threads/posts.

5. The earthing rod should preferably have a minimum length of two metres and be of copper cladded steel or, even better pure copper. If you can use a bronze clamp for the cable connection, do not solder it. The connection should be above ground and then painted with acrylic paint for extra protection.

6. Make sure you main cable is of a sufficient size so you do not get too much voltage drop. Ideally the voltage drop should not exceed 3%, but absolutely no more than 5%.

7. Consider using ABB's products instead of Schneider (Square-D) as they are, IMO, better and also much cheaper, that is if they are procured from ABB's main distributor PMK Corporation in Nonthaburi. You typically save between 1,000 - 1,500 baht per RCBO.

8. Avoid buying the crappy Safe-T-Cut products!

[Crossy]

I can add little to what's been said above.

In the absence of any coherent domestic wiring standard in Thailand the general consensus amongst the knowledgeable is to wire to the Australian AS/NZS 3000:2007 standard http://www.wiringrules.standards.org.au/ which reasonably closely approximates what's done here (without the taped joints and unprotected connections).

Some general information here:- http://www.crossy.co.uk/wiring/

and a long thread http://www.thaivisa.com/forum/Domestic-Ele...ing-t67644.html (note that the attachments from early in this thread have been removed due to space constraints, most of the information is on my site anyway).

[TigertheCat]

Thanks to all the replies,very very useful information and I will act upon this.

I found the forum topic regarding House Electrical Wiring so apologies for starting another thread on the subject.

[powderpuff]

Safety-cut maybe be crappy but they are way ahead of nothing at all.

The way Somchai wires a safety-cut is the only reason he is alive. I have used them for close to 30 years with no big complaints. Having been bitten by 220 a fews times (Safety-cut set to off) it's not fun.