Moved into new house, please some advice?

[ChillinDude336]

Hi,

I've read through a lot of different threads on this forum about RCBOs and grounding and making things safe, however I'm still very confused and maybe someone could shed some light on a few things.
To start my wife and I have just moved to Nan Province, Tha Wang Pha to be exact and we are renting an old house from a Thai Friend. The breaker only has 2 circuits a 32A and a 20A. None of the outlets are the three pin type with grounding. I would like to replace the main unit with a one of these Safe T Cut full units with RCBO built in. If I find someone to install this unit must they run a ground rod and grounding wire in order for the RCBO to protect us from electric shock from appliances we use?  The unit cost 3500Baht, is it very labor intensive to wire and install it?

We plan to install an electric shower hot water heater 4500Watt and purchase a clothes washing machine and new fridge my wife also uses a large sharp toaster oven. All of these devices require proper grounding so can everything including the new breaker box be clamped on to one grounding rod and put in the ground? Do any of you experts have any advice for me? Am I missing something is this not the correct way at all?  I've seen the Safe T Cut box that gets installed before the breaker but I'm thinking that we need to buy a new box entirely because ours only has a 32 and 20 amp circuit and we will eventually have Air conditioners and we use iron often and rice cooker, kettle, small oven etc..

Last question, is it common for devices like Electric shower heaters and Air conditioners to be installed in a way that bypasses the main breaker? For example in our old house I could turn the main breaker off but the AC would still turn on and function. Is that dangerous? My concern is that I'll hire someone to install the hot water heater and they will not run it back to the new Safe T Cut breaker thus not actually using the RCBO incase of leakage.  I've attached pictures of my setup and picture of the Safe T Cut unit I'm talking about. 

I really appreciate your time in reading this and I apologize for my lack of comprehension I'm trying to learn more about it all. 

-Isaac

[bankruatsteve]

I'll give a shot at short answer...

 

RCD/RCBO protects people.  Ground not needed for this device to function.

 

Over-current breakers - "MCD" protects the wire.  Nothing else.

 

Ground protects Class-1 appliance from becoming "hot" (IE: "touch voltage").

 

Ideally you have separate circuits for high draw things, like water heaters and ACs.  Two circuits for the kitchen is recommended for diversity of appliances expected to use.  The only reason for this is to avoid over-current on any one breaker.

 

As for CU, a "Safety-Cut" is just a brand and usually comes with specific size breakers that cannot be changed.  Personally, I would go with a "DIN" style box just because it's easy to adapt.  

[ChillinDude336]

Thanks Steve. So I'll look into getting a DIN style box with some type of RCBO. It's nice to know that even if things aren't grounded the RCBO on the breaker will react and prevent shock. So having the RCBO will be step in the right direction.
 

[bankruatsteve]

Welcome.  The important thing is to use the correct size wire for the maximum current draw expected and size with appropriate breaker.  Specs are in this forum's pins.

[Strange]

This is kinda tough as the place is rented and personally I would not want to re-wire anything. Plus you don't really need to "add" anything to get your place functioning. There are plenty of things you can do that probably are not the safest, but commonly done. 

 

You don't need an earth/ground with RCBO. It sorta measures any difference between L & N so no need earth. 

 

Air con, hot water shower, the big stuff can be wired from main power (before the main breaker) and installed with a breaker on the wall near the appliance. Air con does not really need an RCBO or earth. 

 

You can get a stand alone RCBO and mount that by your existing breaker unit, rewiring is nothing just moving a couple wires. 

 

Your question about the Air Cons and bypassing the main breaker - thats completely normal (how the thais do it) and it will usually have its own breaker in the wall in the room. Thats why it stays on when the main breaker is off. Its not any more unsafe than going through the main breaker. 

 

Your other appliances, kettle, rice cooker, iron, washing machine, will be fine with the current setup but the toaster oven might trip a breaker. In that case you can just run a dedicated circuit to the kitchen with its own breaker and appropriate sized wire from before the main breaker, bypassing it. 

[ChillinDude336]

Thanks Strange. Now I understand the bypassing circuit thing. We are working on the house it's rent free so we are fixing things up a bit just want to make sure we don't get electrocuted. Sounds like we could keep the box and just add a RCBO before it. 

[Crossy]

10 hours ago, ChillinDude336 said:

Thanks Strange. Now I understand the bypassing circuit thing. We are working on the house it's rent free so we are fixing things up a bit just want to make sure we don't get electrocuted. Sounds like we could keep the box and just add a RCBO before it. 

 

Yes, Safe-T-Cut do front-end RCBOs for just that purpose. Your local DIY place or electrical emporium will likely have the beasties in stock.

 

They are not difficult to install, the supplier will often have a man who can do it for a nominal fee. Unless you know what you're doing I wouldn't DIY it because at least some of the installation will need to be done " live"  (even if it's just pulling the meter tails from the meter).

 

Any Class-1 appliance (mostly white goods and desktop computers) must be earthed to be safe. Even with an RCBO your washer or PC can give you a nasty nip and I wouldn't consider using an ungrounded shower heater. No reason not to bash in a short (1m) rod local to each appliance if you don't want to run extra wires.

 

Don't forget, the RCBO / RCD won't protect appliances upstream from it, so if you have a water heater it's really, really advisable to re-wire it to go to the consumer unit, whilst you're at it do the aircons as well.

 

EDIT Or, this may work out slightly cheaper and look less Heath-Robinson than an external box. You could replace that consumer unit with a slightly larger DIN box, those breakers look like they are DIN mount anyway so they could be re-used if the budget is tight. Then add a DIN mount RCD between the incoming 63A main breaker and the MCBs.

 

It's really down to your budget in the end.

 

EDIT 2 What does that 32A breaker supply? How big is the cable from the breaker? You may want to do some juggling if you're installing a water heater.

[ChillinDude336]

2 hours ago, Crossy said:

 Any Class-1 appliance (mostly white goods and desktop computers) must be earthed to be safe. Even with an RCBO your washer or PC can give you a nasty nip and I wouldn't consider using an ungrounded shower heater. No reason not to bash in a short (1m) rod local to each appliance if you don't want to run extra wires.

Thanks for all the great ideas. So an electrician would put a 1 meter rod in the ground and run a ground wire that would go to the fridge.

So for the kitchen we would have a total of 3 ground rods because we will have fridge washer and oven. Is that correct? And so the wires just clamp on the rod is there anything special involved? I'm asking these questions because I want to make sure the electrician does it correctly. 

2 hours ago, Crossy said:

EDIT 2 What does that 32A breaker supply? How big is the cable from the breaker? You may want to do some juggling if you're installing a water heater.

I flipped the switch last night and the lights went out so I know they have the lights on the 32A breaker. As of now nothing is connected we haven't bought fridge yet we are still working on place. 

 

The kitchen only has 1 outlet so I think we will need to add another one. could an outlet bypass the the main unit and get its own elcb breaker located near outlet? Just curious because recently got my hair cut at salon in Chiang mai and they had hot water heater wired into small elcb breaker on wall looked like a nice light switch with a test button. 

 

Ok many thanks for the help, I think I can make this place work. I'm feeling more optimistic about the electrical situation now. 

[bankruatsteve]

17 minutes ago, ChillinDude336 said:

Thanks for all the great ideas. So an electrician would put a 1 meter rod in the ground and run a ground wire that would go to the fridge.

So for the kitchen we would have a total of 3 ground rods because we will have fridge washer and oven. Is that correct? And so the wires just clamp on the rod is there anything special involved? I'm asking these questions because I want to make sure the electrician does it correctly. 

I flipped the switch last night and the lights went out so I know they have the lights on the 32A breaker. As of now nothing is connected we haven't bought fridge yet we are still working on place. 

 

The kitchen only has 1 outlet so I think we will need to add another one. could an outlet bypass the the main unit and get its own elcb breaker located near outlet? Just curious because recently got my hair cut at salon in Chiang mai and they had hot water heater wired into small elcb breaker on wall looked like a nice light switch with a test button. 

 

Ok many thanks for the help, I think I can make this place work. I'm feeling more optimistic about the electrical situation now. 

 

If your lights are on a 32amp breaker chances are they are not wired with 4mm2 which is what would be minimum size for that breaker.  Not good.  Suggest replace with 10A or 15A breaker.

 

For your kitchen, I would extend from the existing outlet adding 2-3 more double outlets with ground to your rod.  Wires can just go under conduit and surface outlets above the splash guard.  

 

 

[Crossy]

I would not add anything to the hot side of that 63A incomer (what meter is installed by the way, 5/15 or 15/45?). If there's already something connected like that then those little RCBOs in boxes are very handy for adding to non-protected circuits. We have a 15mA one protecting our pool kit which is actually plugged into a regular 30mA protected outlet,  I'm paranoid about zapping the grand kids.

 

Lights on a 32A, replace with something more sensible say 10A (ours follow UK practice of lights on 6A breakers), even if there are outlets on the same breaker you shouldn't go over 20A. Do check the wiring size.

 

If you are adding outlets in the kitchen make then 3-pin and add a single rod, looks nicer too. Run flat 3-core cable on the surface, spur off the rod from one of the outlets which is convenient.

 

Before going to work list out exactly what you intend doing in a simple list. Then we can go through line by line and come up with a safe and sensibly priced solution.

 

 

[ChillinDude336]

Looks like 5/15 on Meter. 

How do I check the wire size? And you mention adding grounded sockets in kitchen does that require a 5th grounding rod or do all the ground wires come off one grounding rod? 

Switching the lights to the smaller circuit is just a matter of the electrician moving the location within the circuit box?

 

I should be ready to get some of this started next week. So I should change the circuit box to a style with more slots? Or is that not necessary? 

 

Thanks so much! 

[Crossy]

Yup, that's a 5/15, it sure as heck shouldn't have a 63A incoming breaker, 20A is more the correct size (15A is the maximum current the meter is rated for).

 

Your kitchen outlets, assuming you'll be using them for the washer, fridge etc. will provide the ground to your appliances, wire all the outlets to one rod.

 

If you're not going to add aircon, just a water heater, limit the water heater to a 3.5kW unit, hook it to the 32A breaker in the box (you should really replace that with a 20A). Move the lighting to the 20A breaker. Add an RCBO as indicated earlier.

 

You'll still be fine on the 5/15, they don't explode easily but I wouldn't want to take it over 30A.

 

 

 

[ChillinDude336]

11 minutes ago, Crossy said:

Your kitchen outlets, assuming you'll be using them for the washer, fridge etc. will provide the ground to your appliances, wire all the outlets to one rod

Great thanks for clarifying that. The last fridge I had only had a two prong connector do I need to buy special outlets that have a protruding pin for ground? 

 

Also so we will be adding two 9000 btu acs do we need to contact power company to upgrade Meter?

Thanks again 

[Crossy]

12 minutes ago, ChillinDude336 said:

Great thanks for clarifying that. The last fridge I had only had a two prong connector do I need to buy special outlets that have a protruding pin for ground? 

Thanks again 

 

Ah, now we move to the issue of many appliances being fitted with Schuko (European) plugs

 

If your appliance has a plug that looks like this:-

 

 

You should really remove it and replace with a local grounded plug. You did used to be able to get the correct outlets (German style with side contacts for ground, the ones with the pin in the outlet are French / Belgian, the plugs are universal) but they seem to have dried up.

 

Thai grounded outlets look like this:-

 

 

Thai grounded plugs look like this :-

 

 

or this;-

 

 

Have a look here http://www.crossy.co.uk/wiring/plugs.html sadly the Schuko adaptors on that page also seem to have dried up

 

and here http://www.crossy.co.uk/wiring/2pin.html

 

This PEA document may be worth a look http://www.crossy.co.uk/Handy Files/groundwire.pdf

 

 

 

[ChillinDude336]

Ok awesome THANK YOU! I bought a Panasonic 4500 watt shower heater last week at big c for 3200 baht. Hmm so it will blow the Meter?  

[bankruatsteve]

You won't "blow" the meter but with that heater and the rest of the stuff you want, you really should get the PEA to up the meter to 15/45 and make sure the incoming cables are OK for that (the PEA will probably let you know).

 

[Crossy]

+1 ^^^

 

4500W @ 220V is about 20A, the meter will be fine, but don't boil the kettle at the same time :)

 

 

[ChillinDude336]

Ok so I have a plan of action now! I'm gonna look for an electrician now. 

 

My plan. 

1: contact Local PEA and get information and cost associated with 15/45 change 

 

2: Find good electrician and have RCBO front unit installed and switch lights to 20 amp circuit and install two grounded outlets in kitchen for wash machine rice cooker oven fridge oh yea change appliance plugs to grounded type! Very important. 

 

If the kitchen outlets are grounded and the plugs on appliances are switched to grounded types then I'm all set correct? I don't need any additional grounding right? I'll also have the RCBO setup as additional safety feature. 

 

This whole process electrical dilemma had me very overwhelmed and you all have helped me feel like I'm in control of the situation and the safety of my family. I really appreciate it! I hope I can use all the knowledge I've learned to steer other people in the right direction in regards to grounding and RCBO devices. Thanks!

[Crossy]

PEA may want you to replace that 63A incomer with a 50A when you change the meter.

 

You'll need a ground for your water heater too, either a separate rod or run from your kitchen rod.

 

Run the heater off your (now spare) 32A breaker.

 

Otherwise you're good to go I think.

[ChillinDude336]

Ok heater on 32 will do.

if I'm going to need to replace 63 with 50 and buy 3000 baht safe t cut is there any reason I shouldn't just pay 3500 for one of these safe t cut full boxes. Maybe stand alone unit is better? Just wondering what you guys think. Thanks 

[bankruatsteve]

If the breakers fit for what you need, go for it.  But, I think you said that you will be finding/hiring an electrician to do the work.  Why not do that first and see if he agrees or maybe has a different solution?

 

[Crossy]

The one thing I would NOT do is buy a pre-configured unit, unless it has exactly the breakers you need (they rarely do).

 

 

[tutsiwarrior]

a great thread! I have a lot of the same concerns as the OP but I got a safety - cut CU already installed...some folks came by about 10 years ago selling them outta the back of a pickup and the installation isn't the best but the main breaker trips if you touch the test button...I'm gonna haveta check and see if the small power circuits are on smaller breakers...

 

I'm gonna install an additional 3.5kW shower water heater and an additional 24k Btu AC unit (we got 15/45)...the existing AC and water heater are connected to the main supply upstream of the CU...

 

so it's OK to connect all the new grounds to the existing copper rod?

 

 

 

 

[Crossy]

10 hours ago, tutsiwarrior said:

so it's OK to connect all the new grounds to the existing copper rod?

 

Yup, use one rod.

 

I would move the existing A/C and heater on to the Safe-T-Cut CU for safety and peace of mind that there's something between those taped joints and the (for our purposes) infinite energy of the grid.

[ChillinDude336]

Follow up question. I bought the grounding rod very big one about 8 feet also bought elcb breaker for shower heater. How do I connect multiple ground wires to this rod.? Must I buy multiple clamps and connect each stripped earth to a different clamp on the rod? Or do I connect all stripped earths to same clamp on rod? I would like to ground wash machine and fridge to this rod also. Thanks again for all the replies and help.  Just so you know I am searching for already created topics but I can't find anything that answers my question. Exactly.

[Crossy]

You "should" run all the grounds back to the consumer unit (there ought to be a ground bar in there) and then one wire to the rod.

 

The pragmatic approach would be to run all the wires to the rod, give them a good solid twisted connection and put them in the one clamp. You may want to paint the connection with acrylic paint to prevent corrosion.

[ChillinDude336]

14 hours ago, ChillinDude336 said:

 

Ok this makes more sense to me now. Could I add some type of earth network in kitchen and run main earth cable to bar and other earths tie In there? Is that completely off or possible safe and something that would actually work? If that would work do I just purchase an earth terminal block? If that isn't correct I'll just twist and clamp and run them into house. I want to setup all the non live earthing before sparky comes so I can make sure it is done correctly then he can do the stuff that I would kill my self attempting. I'm looking at this earth rod thinking how am I gonna sink this thing. Guess I'll need a sledge. Thanks again my wife also says THANK YOU!!!. If we ever cross paths I owe you some beer.

 

[bankruatsteve]

Another alternative for earthing would be to run a wire "bus" from your rod around the exterior of your house and connect to that for all desired points.  

[ChillinDude336]

21 minutes ago, bankruatsteve said:

Another alternative for earthing would be to run a wire "bus" from your rod around the exterior of your house and connect to that for all desired points.  

You are blowing my mind. I guess I have another research project. As it stands the twist all and clamp method sounds the simplest and most realistic for me. I just need to make a decision and get started. 

[bankruatsteve]

2 minutes ago, ChillinDude336 said:

You are blowing my mind. I guess I have another research project. As it stands the twist all and clamp method sounds the simplest and most realistic for me. I just need to make a decision and get started. 

 

Running a bus seems simpler than multiple runs to me but you should go with whatever makes sense to you.