Drawing Too Much Electricty / Consumer Unit / Plastic Consumer Unit Box

[sometimewoodworker]

4 hours ago, Metropolitian said:

The regulations outside for the electric company is to have their transformer earthed and the neutrals too at some points (Crossy referred to a reg of every three poles need a link to earth from neutral) but the reality is that the electric company (here anyway) only connect the end points of the neutral lines at the poles.

 

To add: in my block there is nothing, the neutral lines don't have earth links and the transformer was replaced years ago and they probably forgot to reconnect the earth link. The only way the neutral get earth is from us, the consumers.

Don’t forget that not all of Thailand is on TN-CS (using MEN) and AFIK if you aren’t on that ( @Crossy will confirm) you should not link neutral to earth.

[Crossy]

22 hours ago, sometimewoodworker said:

Don’t forget that not all of Thailand is on TN-CS (using MEN) and AFIK if you aren’t on that ( @Crossy will confirm) you should not link neutral to earth.

 

My advice takes two courses:-

 

1. If you already have a permanent supply (pay 4 Baht a unit) and you are upgrading/refurbishing the existing electrics then do NOT add a MEN link unless you are certain that your supply is already MEN (you definitely do NOT want to be the only N-E link). Best way to check is to have a look at the supply poles, if you see an earth rod linked to the neutral (usually the top one of the 4 LV wires) on every 3rd pole or so then you have MEN and can safely add a N-E link. If there are no pole earth rods, do not add a link but please ensure you have an RCD/RCBO/Safe-T-Cut.

 

2. If you don't have a permanent supply yet (pay 8 Baht per unit) then you will need to pass an MEA/PEA inspection. It's pretty rudimentary but the inspector will expect to see the N-E link implemented as per the Thai regulations. What you do after he's gone is up to you, I would do a survey as above then remove the link if you don't see the pole ground rods, same advice for RCDs.

 

Our inspector spent 5 minutes looking inside the CU, 1 minute looking at the top of the ground rod and the rest of the 30 minute appointment drinking coffee and gassing with Madam. We had to have a re-test as he didn't like the 63A incoming breaker (on a 15/45 meter) so I replace it with a 50A which he was happy with (the 63A is back in now).

 

[Cashboy]

On 12/16/2019 at 6:26 AM, Crossy said:

 

My advice takes two courses:-

 

1. If you already have a permanent supply (pay 4 Baht a unit) and you are upgrading/refurbishing the existing electrics then do NOT add a MEN link unless you are certain that your supply is already MEN (you definitely do NOT want to be the only N-E link). Best way to check is to have a look at the supply poles, if you see an earth rod linked to the neutral (usually the top one of the 4 LV wires) on every 3rd pole or so then you have MEN and can safely add a N-E link. If there are no pole earth rods, do not add a link but please ensure you have an RCD/RCBO/Safe-T-Cut.

 

2. If you don't have a permanent supply yet (pay 8 Baht per unit) then you will need to pass an MEA/PEA inspection. It's pretty rudimentary but the inspector will expect to see the N-E link implemented as per the Thai regulations. What you do after he's gone is up to you, I would do a survey as above then remove the link if you don't see the pole ground rods, same advice for RCDs.

 

Our inspector spent 5 minutes looking inside the CU, 1 minute looking at the top of the ground rod and the rest of the 30 minute appointment drinking coffee and gassing with Madam. We had to have a re-test as he didn't like the 63A incoming breaker (on a 15/45 meter) so I replace it with a 50A which he was happy with (the 63A is back in now).

 

It is going to be a new supply to a new house:

 

For the building work, 2.5 mm live and neutral cables were connected directly (no earth, no fuse, no RCD) to the old house supply ( 5 / 15 ) meter.

That seems to be pretty typical.

 

The intention is to keep the old government mains supply to the old house and have a new government mains supply  ( 15 / 45 ) to the new house.

By the way, on that pole there are 7 meters and 6 are ( 5 / 15 ) and one ( 15 /45 ).

 

I was thinking that I would simply put a 100 amp mains switch inside the loft and the live and neutral would be connected to a 15 / 45 meter on the outside pole and then I please myself what I wanted to do.

 

I was going to ask should I use 25mm aluminium for this or 16mm copper.

What is better?

 

You say "if there are no pole earth rods, do not add a link but please ensure you have an RCD/RCBO/Safe-T-Cut".

There are going to be two RCDs in each consumer unit is that what you mean?

What is a safe T-Cut (picture of correct one would be appreciated) and what spec one would I need.

 

 

 

 

[alacrity]

Schneider distribution boxes I have used for mains input have always been metal cased (up to 1 year ago).

Plastic cased boxes should have an IP rating (primarily indicating the level of tolerance of contaminant ingress).

I would never use a metal Distribution Box outdoors.

[Cashboy]

11 minutes ago, alacrity said:

Schneider distribution boxes I have used for mains input have always been metal cased (up to 1 year ago).

Plastic cased boxes should have an IP rating (primarily indicating the level of tolerance of contaminant ingress).

I would never use a metal Distribution Box outdoors.

I bought my plastic Schneider consumer units in the UK; probably because of directive 17 or whatever.

I only paid £20 => 1,000 bt each so worth buying just for the RCDS in my opinion.

I then bought 12 x 20 Amp MCB for £12 for single power supplies.

I intend to use two of these ( one for upstairs and one for downstairs ).

 

I am not an electrician but would have though plastic was safer because you are less likely get short circuits and the case becoming live but I am only a simple accountant in reality, certainly not an electrician.

I cannot believe how complicated a simple domestic supply seems to have become reaqding these threads.

 

[Metropolitian]

3 hours ago, Cashboy said:

What is a safe T-Cut (picture of correct one would be appreciated) and what spec one would I need.

Safe-T-Cut is a brand name and very known of their marketing strategy in Thailand, especially when Thailand went in the changeover to use RCBO's and safety systems.

They sold a big size standalone RCBO, with manual setting of the trip moment. (mA leak).

Now they sell DIN 35 rail size rcbo, and still use the knob to set the trip moment.

In Thailand, and most countries this is 30mA at the RCD. (In the USA 5mA and called GFCI).

from left to right: the stand alone RCBO with main breaker and sensitify button, built in a big case with a Scheider Square D consumer unit and the right picture the more recent DIN rail consumer unit from STC with the same system.

 

 

[sometimewoodworker]

Hummm

 

 

that is certainly an exciting way to have your line bus bar!!

 

Designed to permit simple access to give the best shock possibility?

 

Even Thai boxes are nowhere that dangerous. 

[bankruatsteve]

12 hours ago, Cashboy said:

I was going to ask should I use 25mm aluminium for this or 16mm copper.

What is better?

You will want to ask the PEA.  Mine wanted Al.

[Crossy]

9 hours ago, sometimewoodworker said:

that is certainly an exciting way to have your line bus bar!!

 

I'm surprised that a Schneider box doesn't have at least a clip on plastic cover for the bus-bar, maybe it's still in the box somewhere.

EDIT Looking at the Schneider catanddog it seems there's no cover, the later version has a plastic coated bar. Plasti-dip anyone? https://forum.thaivisa.com/topic/725732-where-can-i-buy-plasti-dip-in-bangkok/

 

 

If there's no cover I would be applying a couple of layers of tape just for my peace of mind (large areas of copper frighten me).

 

Since it's behind a cover requiring tools to remove it's actually perfectly fine for BS7671 (except it's plastic).

[sometimewoodworker]

2 minutes ago, Crossy said:

 

Since it's behind a cover requiring tools to remove it's actually perfectly fine for BS7671 (except it's plastic).

Really! I’m astonished that it would be permitted.

 

The placement of the line terminal also seems a little less than optimal making a plastic cover for the bus bar a much more difficult shape, and I can see no value in arranging it like that. 
 

 

 

[Crossy]

1 minute ago, sometimewoodworker said:

and I can see no value in arranging it like that. 

 

Agree, decidedly odd. I also get confused by the main switch being on the right (seems to be the style these days), it always used to be on the left end.

 

[Metropolitian]

7 hours ago, Crossy said:

If there's no cover I would be applying a couple of layers of tape just for my peace of mind (large areas of copper frighten me).

 

Since it's behind a cover requiring tools to remove it's actually perfectly fine for BS7671 (except it's plastic).

Behold.. the cover ????

 

Finish it with a sticker 

 

The only thing that would bother, are those copper lips between the open unused space

when not use the 'gangs' put a heat-shrink on these lips and be done with the shivering. (pun intended)

 

 

[Crossy]

4 minutes ago, Metropolitian said:

Behold.. the cover ????

 

Grey on grey + old eyes ????

 

Of course now it's so obvious I can't un-see it.

 

[Metropolitian]

8 hours ago, Crossy said:

 

Agree, decidedly odd. I also get confused by the main switch being on the right (seems to be the style these days), it always used to be on the left end.

 

Funny.

I always have known the UK real-fuse boxes with the main switch on the right side, so are most of the UK Consumer Units.

And just now some boxes do have the main switch on the left side same as most of the Europeans do with the DIN Consumer Units.

Wylex , Schneider, they tend on the right side while Hager and Volex are Lefties.

 

I am not sure of the history but perhaps of the situation most cut out fuses and the meter are positioned?

 

I am from the mainland (NL) and there we have 'stackable' boxes with all the electric items inside, main cutout switch, main fuse, the meter in that order and then the customer side with rcbo/rcd and the breakers (long time ago screw-in fuses and mind you a lot of open busbars in there). The electricity cable came from under.

A wide used brand was the Holec (now Eaton).

We have, like all other houses in the NL, have a small wardrobe like space or in wall panel for all this where mostly also the gas meter is positioned.

 

After moving to Thai I came in contact with so called Consumer Units.

 

[Cashboy]

9 hours ago, Crossy said:

 

I'm surprised that a Schneider box doesn't have at least a clip on plastic cover for the bus-bar, maybe it's still in the box somewhere.

EDIT Looking at the Schneider catanddog it seems there's no cover, the later version has a plastic coated bar. Plasti-dip anyone? https://forum.thaivisa.com/topic/725732-where-can-i-buy-plasti-dip-in-bangkok/

 

 

If there's no cover I would be applying a couple of layers of tape just for my peace of mind (large areas of copper frighten me).

 

Since it's behind a cover requiring tools to remove it's actually perfectly fine for BS7671 (except it's plastic).

Covers for buzbar are in the box I recall.