Earth to RCD safety check on professional worker

[djtheoz]

After reading many many threads, and thanking Crossy and some others in particular for loads of contributions, I do feel the urge to consult with you about the safety of a particular electric installation.

My misses builds a restaurant. She knows all about food and nothing about sparks so I helped a bit. My ‘job’ on this project was the design (where to mount the plugs and switches, lights and fans) and we would hire a local professional (…) to install the wiring and breaker box.

I insisted on having a earthed installation because of working with metal kitchen equipment and water.

OKAY. The guy started .. using 2 wires red 2,5 mm2 and 1 blue 2,5 mm2 which would be Live Neutral and Ground. I suggested to use the green/yellow wire which was on the table just in front of him, and if it wouldn’t be a good idea to use different colors for Live and Neutral.

He says it is ok, no problem. And just leaves it as he started and moved on. Yeah.. right!... I am clearly not the professional. What was I even thinking! Crazy farang man.

Long story short, despite of all faulty and inconsequent and mixed up color coding, the taped joints, poorly mounted boxes and tube plugs onto walls, no sense for aesthetics where to mount pipes and what not… my true concern is the Earthing system.

The guy put a 1.2 meter earth rod into the soil next to the building (he says,. I haven’t seen it) and connected 2 x 1,5 mm2 from the GND bar to the rod outside. No protection outside, just single wires. (grey and black..) See picture.

Inside the breaker box it is a rainbow colored mess, but is it connected correctly? All plugs work.. lights go on and off. But.. well. yeah. Is it safe?

I noticed there was no connection between N and GND, as I have seen that on drawings here, and on the diagram sticker inside the Chang U8 breaker box.

I asked the guy about this and he instantly put a direct connection between the N and GND bars, without acknowledging if it should be there or not. Maybe just to please me, or did he make a  mistake? I dont know. Though I dont trust this guy for a millimeter and I am seriously worried we now have created a dangerous situation.

Should the GND not be connected to the Input Neutral of the 2-ch main RCD switch, instead of to the Output Neutral as it is now with the nice yellow 4 mm2? Does this even matter?

Should I test the earth with the 15 W light bulb between the rod and the L ?

How can I test if a leak will cause the RCD to trip and switch off mains?

I just want it to be safe for my girly to work in.

Any (correct) input is very much appreciated. Thank you

Edited July 18, 2018 by djtheoz

[bankruatsteve]

Not the way PEA like to see it.  Your first photo is the ground rod?  Not good if so.

 

Otherwise, a bit messy but looks OK to me.

 

 

[carlyai]

Not the way PEA like to see it.  Your first photo is the ground rod?  Not good if so.
 
Otherwise, a bit messy but looks OK to me.
 
 

I can't see where that joined blue wire goes and what it is spliced to. Also the green yellow joined wires.
Can you tell where they go?



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[djtheoz]

Thanks so far;

The green/yellow are connected to the 3rd pin on the wall power sockets in the building, that is, through taped splits to other colors and gauges in several wire joint boxes. 

The blue joints in the bottom of the box are Neutrals from power sockets just below the breaker box and are connected to the N bar.

 

And yes... the grey and black 1,5 mm2 wires on the first picture both go from the GND bar in the breaker box into the soil outside the building and have a 1.2 meter ground rod connected to it, burried. 

This would be the "earth" connection in this system.... which I am a bit worried about.

 

 

 

 

[carlyai]

Thanks so far;
The green/yellow are connected to the 3rd pin on the wall power sockets in the building, that is, through taped splits to other colors and gauges in several wire joint boxes. 
The blue joints in the bottom of the box are Neutrals from power sockets just below the breaker box and are connected to the N bar.
 
And yes... the grey and black 1,5 mm2 wires on the first picture both go from the GND bar in the breaker box into the soil outside the building and have a 1.2 meter ground rod connected to it, burried. 
This would be the "earth" connection in this system.... which I am a bit worried about.
 
 
 
 

I'd also be a bit worried about those joined wires.
Can you get a picture of where those joined wires go?
Does the blue wire go to power outlets, or power and lights and fans etc.?


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[Crossy]

Your N-E link (with the "correct" arrow) is incorrect. Wired like that the incoming RCBO won't stay on.

 

Any N-E link must be from the incoming neutral for MEN to work properly.

 

The correct "Thai" wiring for MEN is like this

 

 

Incoming neutral to the earth bar then to the RCBO neutral terminal.

 

Wire it like this and Mr PEA will (probably) pass the inspection.

[Crossy]

If you're using a local sparks this PEA document may be useful.

 

58ddd93267998_GroundwireMk2book-Manual.pdf

 

Note - If you're just looking at the pictures, the first diagram on page 13 (page 7 of the PDF) is showing you how NOT to do it.

[rwill]

get yourself one of these socket testers and check all the sockets.  I had a room added and when I started checking the sockets almost every other one had line and neutral reversed.

 

[djtheoz]

5 hours ago, rwill said:

get yourself one of these socket testers and check all the sockets. ................

Live is connected to the correct pin on every socket, I checked with a multimeter. Color of the wires are just not quite consistent.

We got red, yellow, brown and blue Live wires. Same colors are used for the Neutrals too. Oh and black. Oh similar for the GND wires. (!)

But thanks though, it is a good thing to have, not a whole lot of money either. I'll buy one and get the plug adapter for it too.

 

8 hours ago, carlyai said:

I'd also be a bit worried about those joined wires.

I actually had scary dreams about ALL details of this installation... seriously.

But trying to keep this thread a bit less messy than the main joints box just above the breaker box, which has 8 groups all spliced, twisted and taped up. See picture.. 

The joined wires in the box you mentioned, are Neutrals. or Lives, used for power outlets just below the circuit box, connected too group #4. 

I measured the outlets and seem to be ok....

 

8 hours ago, Crossy said:

Note - If you're just looking at the pictures, the first diagram on page 13 (page 7 of the PDF) is showing you how NOT to do it.

Thanks . It is nearly what they did - connected the GND bar directly to the N bar of the RCB output. Difference is in- and output connected to same bar...

If i understand well - re routing the GND bar connection to the N-input of the RCB would be an improvement (see diagram) ?

 

Also, in this book I see ">= 2.4 เมตร " at the length of the earth rod. In my home country this means 'equal or higher than'. 

This is not what they used, they used a 1.2 meter rod, as they said. With those 2 x 1,5 mm2 wires connected to it. Seems way to short to me.

Could it still work properly and how to test this ?  We are based in Pai, Mae Hong Son by the way.. in the valley not much higher than the river level.

Should I connect a 15 Watt light bulb between L and GND rod and see if there is a current flowing?

 

Hmm another thing I measured a consistent 12 Volt ac on all outlets between L and N with main breaker switch turned OFF.

Is this common?

 

[Crossy]

OK, your new diagram is electrically correct.

 

BUT likely won't pass muster if you need the PEA inspection for a permanent meter, the inspectors like to see it done their way.

 

If you already have a permanent supply (4 Baht per unit) rather than a construction supply (8 Baht per unit) it will be just fine as the diagram.

 

Meatech (part of MEA) do a 220V outlet tester with the right plug, not sure if they do mail order or you need to get someone in Bangkok to buy for you. 

 

http://www.mea.or.th/minisite/meatech

 

[Fruit Trader]

46 minutes ago, djtheoz said:

I love those artistic Thai junction boxes. They should all be fitted with clear covers for continued appreciation .

[Jdietz]

[sarcasm]

And the right way to test this is with the electrician holding a black or brown wire while standing in a puddle of water.

 

Result Check Chart:

1. No effect  -  Power is switched off or wire colors incorrect

2. Electrician yelps and dances in an unprofessional way  -  RCD not working correctly

3. Electrician disappears in a cloud of smoke  -  Hooked up to the HV side, check transformer

4. Everything suddenly went dark and electrician looks confused  -  RCD hooked up correctly

[/sarcasm]

 

Added tags for the humor impaired.

 

Edited July 19, 2018 by Jdietz

[bankruatsteve]

I'll say it again... The Thai "twist and tape" is probably a lot better than most other options here.  Why?  Because the twist makes a very good connection and that what is needed.  The tape is another subject but most tapes used should be OK.  On the other hand, the above photo shows a box overloaded no matter what kind of connections.  Should have a bigger box or two.

[Jdietz]

There's always room for one more!

[watcharacters]

8 hours ago, rwill said:

get yourself one of these socket testers and check all the sockets.  I had a room added and when I started checking the sockets almost every other one had line and neutral reversed.

 

 

 

How did you resolve that with the installer?

 

[watcharacters]

15 minutes ago, bankruatsteve said:

I'll say it again... The Thai "twist and tape" is probably a lot better than most other options here.  Why?  Because the twist makes a very good connection and that what is needed.  The tape is another subject but most tapes used should be OK.  On the other hand, the above photo shows a box overloaded no matter what kind of connections.  Should have a bigger box or two.

 

 

What's the cost of Scotch Loks  (wire nuts)?        Can't be more that a few hundred of them used in the typical house.    Tape that dries and falls away?    

[Fruit Trader]

30 minutes ago, watcharacters said:

 

 

What's the cost of Scotch Loks  (wire nuts)?        Can't be more that a few hundred of them used in the typical house.    Tape that dries and falls away?    

The favourite trick is to twist and tape exposed joints in a roof space where the heat slowly unwinds the tape leaving exposed conductors. 

 

Wire nuts and proper size boxes are way too expensive. One must also consider the workers training and experience as there's a good chance he woke up one morning wearing an electricians hat.

[rwill]

38 minutes ago, watcharacters said:

 

 

How did you resolve that with the installer?

 

I told him to stop doing the electric work.  I had my air guy come in and rewire the whole house.  I needed a bigger breaker box with a safe-t-cut anyway.

 

[rwill]

42 minutes ago, watcharacters said:

 

 

What's the cost of Scotch Loks  (wire nuts)?        Can't be more that a few hundred of them used in the typical house.    Tape that dries and falls away?    

or use the heat shrink tubes...

 

[watcharacters]

7 minutes ago, rwill said:

or use the heat shrink tubes...

 

 

I never used heat shrink in my life.

 

Are they as easily removed and replaced as Scotch Loks with either a larger or smaller scotch lok?

 

 

[carlyai]

'Hmm another thing I measured a consistent 12 Volt ac on all outlets between L and N with main breaker switch turned OFF.

Is this common?'

 

I'm not sure if the others missed this, but I would think this is not common.

 

I'm not the Guru here, but if your ground rod is not a good earth or 0V this could be a problem.

When you fix the ground rod problem (remember to leave the top section, that the earth wire connector screws onto the rod, exposed; so you can see it.), then check this AC volts again.

 

You don't have a computer or UPS or anything working when you open the main breaker? If you have, unplug these and measure again.

 

Different Subject

 

In the main breaker box you seem to have 9 active wire connections from the breakers. It's hard to see, but do you have 9 neutral connections?

 

 

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[lopburi3]

I have found this type of connector far better than wire nuts and China versions are available from aliexpress at reasonable costs.

[Jdietz]

Would you happen to have an Aliexpress or similar link to those?

[Crossy]

9 minutes ago, Jdietz said:

Would you happen to have an Aliexpress or similar link to those?

Just search AliExpress for "Wago" for 1,700 results.

[bankruatsteve]

Lazada has "Wago" but whose know.

[sometimewoodworker]

1 hour ago, Jdietz said:

Would you happen to have an Aliexpress or similar link to those?

Dx link I use DX often

[watcharacters]

On 7/20/2018 at 6:08 PM, sometimewoodworker said:

Dx link I use DX often

 

 

Scotch locks are   the global standard.

 

Inexpensive and  feasible adaptable  to all situations.

 

Yellow, red, Grey,  Blue and then you need other applications to secure a good connection.

 

Wire nuts are for smaller applications

 

Your local electrician handyman can fill you in on all the latest.

 

Good luck..

 

 

[Jdietz]

My local electrician handyman stands barefeet on concrete on a 7/11 bag and has never heard of such modern things like 'ground'

I'll figure it out myself, thanks ?

 

[carlyai]

Hi, did you fix the earth rod and check that AC voltage again?
No worries, just curious.

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[sometimewoodworker]

5 hours ago, watcharacters said:

Scotch locks are   the global standard.

 

Inexpensive and  feasible adaptable  to all situations.

Only if you are doing automotive wiring and even then bullet and spade connections are far more commonly used.

 

I've never seen them used in domestic or commercial electrical wiring