Consumer Unit basics

[Crossy]

10 minutes ago, Cashboy said:

I bought them second hand for 500bt

Deal!

 

They're 51 Quid a pop (new) at PowerDiscount https://www.powerdiscount.co.uk/wylex-108m-metal-clad-1-way-switch-fuse-housing-784-p.asp

 

 

[Cashboy]

1 minute ago, Crossy said:

Deal!

 

They're 51 Quid a pop (new) at PowerDiscount https://www.powerdiscount.co.uk/wylex-108m-metal-clad-1-way-switch-fuse-housing-784-p.asp

 

 

I bought 3 second hand on on ebay-UK for £10 ( 440 bt) each with the cartridge fuse.

I bought a 100Amp one for £15 ( 645 bt).

[bankruatsteve]

Just to say... the Chang switch is 1-200 baht full price.  

[Crossy]

9 minutes ago, bankruatsteve said:

Just to say... the Chang switch is 1-200 baht full price.  

Indeed, but it looks like this :-

 

 

Where's Boris Johnson Karlov, Peter Cushing et-al when you need them?

 

"More volts Igor, more volts!!"

 

http://www.imdb.com/list/ls069170661/

 

[Crossy]

1 minute ago, Arjen said:

And the replacement "fuses" one Baht..

On a 100m roll

[bankruatsteve]

2 minutes ago, Crossy said:

Indeed, but it looks like this :-

 

 

 

Where's Boris Johnson Karlov when you need him?

 

"More volts Igor, more volts!!"

 

What?  Not decorative for you?  Well, they work and that's all I need.

[Crossy]

1 minute ago, bankruatsteve said:

What?  Not decorative for you?  Well, they work and that's all I need.

I was thinking more of "safe" and covering my backside when recommending to someone I don't know

 

IIRC you can get the cover off the fuse with the juice on.

[bankruatsteve]

1 minute ago, Crossy said:

I was thinking more of "safe" and covering my backside when recommending to someone I don't know

 

IIRC you can get the cover off the fuse with the juice on.

OK.  But you can also get the cover off of "safe" stuff with a screwdriver and a few twists.  Maybe there's a difference but I don't see it.

[Crossy]

Just now, bankruatsteve said:

But you can also get the cover off of "safe" stuff with a screwdriver and a few twists.  Maybe there's a difference but I don't see it.

To open the Wylex unit with the power on (or to get the power on with the cover off) requires you to knowingly defeat the safety interlocks.

 

With Mr Chang "what are safety interlocks?" Those who know what we are doing need to protect those who don't (like by putting Mr Chang way up high).

[Crossy]

Just now, Arjen said:

So one Baht....!

But I do question the word "fuse", I prefer the term "fencing wire"

[Crossy]

4 minutes ago, Arjen said:

That is why I placed these "" but as always you are correct!

Way (waaaay) back I went to a (council owned) house in the UK and discovered every plug had the fuse wrapped in silver foil. Looking in the old (re-wireable) consumer unit I spotted that every fuse had been "replaced" by something rather thicker than fuse-wire. On checking some of the wrapped plug fuses they were actually intact.

 

According to the man of the house it was "to stop them blowing", the whole place was "protected" by the 100A incoming fuse.

 

Amazingly they moved out before it burned down, that was a few weeks later when a new couple moved in, luckily they escaped.

[bankruatsteve]

23 minutes ago, Crossy said:

To open the Wylex unit with the power on (or to get the power on with the cover off) requires you to knowingly defeat the safety interlocks.

 

With Mr Chang "what are safety interlocks?" Those who know what we are doing need to protect those who don't (like by putting Mr Chang way up high).

Aha.  Maybe you have never tried to get the Mr. Chang cover off?  Actually, putting it back on is the test.  Why would anything connected to mains voltage be accessible to children?  Yah, usually way up high or inside cabinet.  Idiots can and will get into whatever.  

[Cashboy]

I am going to run 32 Amp ring mains in the house in Thailand like the UK.

One for upstairs

One for Downstairs

One for the Kitchen

 

Is this a risk with no fused plugs in thailand like we have in the UK?

Or should I run inline fuses in apppliances like TVs etc?

 

 

 

[Crossy]

12 minutes ago, Cashboy said:

I am going to run 32 Amp ring mains in the house in Thailand like the UK.

One for upstairs

One for Downstairs

One for the Kitchen

 

Is this a risk with no fused plugs in thailand like we have in the UK?

Or should I run inline fuses in apppliances like TVs etc?

Do NOT, that's NOT run 32A ring-finals like the UK. Thai unfused plugs make it a recipe for a fire.

 

Run radials in 2.5mm² cable on 20A breakers. If you think about it, replacing one ring (32A) with two radials (20A x 2) gives you an extra 8A for the cost of one breaker.

 

Even in the UK rings are going out of favour, but there we would use 4mm² radials on the 32A breaker ( remember, fused plugs).

[Cashboy]

I shall need two consumer units then I would think.

 

The consumer unit I have comprises

1 No  100 amp main switch

2 No MCBs with no RCD; useful for fridges and CCTV and alarms

2 No RCDs each with 5 No MCBs.

i.e. I have a total of only 12 MCBs for a house of 270 m2

 

 

[Cashboy]

What are the regulations about Consumer Units in Thailand?

Does it state anywhere that they have to be metal like introduced in the UK recently?

 

I say that because I bought this from UK Ebay for £28 (1,204 bt) delivered.

 

Schneider Plastic Box:

100 Amp mains switch

2 No. 80 Amp 30mA RCDs

12 slots ( 5 + 5 + 2) for MCBs

 

It takes the Schneider MCBs available in Home Pro.

 

 

 

 

 

 

 

 

[Cashboy]

1 hour ago, Crossy said:

26 minutes ago, Arjen said:

I am wondering.... you are in Thailand. To be connected you need to follow Thai rules. Why do you buy on UK?

 

The provided equipment here is OK. The problem is sometimes how it is connected.

 

Arjen.

 

I saw the price of Consumer Units in Home Pro three years ago and saw the prices of RCDs.

So when I saw special offers on Ebay UK thought I would buy the Schneider unit because the cost of one RCD in Thailand was not much less than the price I paid for 100 Amp switch, 2 RCDs, buzz bars and the box.

I could not find a good fused isolation switch when looking in Thailand and again at 430 bt where am I going to find a quality fused isolation switch in Thailand.

I am not a rich farang like you.

Edited January 31, 2018 by Cashboy

[Crossy]

9 hours ago, Cashboy said:

Does it state anywhere that they have to be metal like introduced in the UK recently?

Nope, no restrictions on materials. We have plastic ones (ABB so not cheapo) my personal preference is for an insulating box.

 

Actually the UK regs don't specify "metal" just "non combustible", so concrete would be just fine.

 

I see your CU is DIN mount, that's good coz you can get all manner of accessories (contactors and the like) and many brands of MCB etc. will fit.

 

[Cashboy]

19 hours ago, Crossy said:

Do NOT, that's NOT run 32A ring-finals like the UK. Thai unfused plugs make it a recipe for a fire.

 

Run radials in 2.5mm² cable on 20A breakers. If you think about it, replacing one ring (32A) with two radials (20A x 2) gives you an extra 8A for the cost of one breaker.

 

Even in the UK rings are going out of favour, but there we would use 4mm² radials on the 32A breaker ( remember, fused plugs).

 

You have now knocked me back on my thinking and believe that for a house of 270 m2 will need more than 12 MCBs if changing from 32 Amp ring to 20 Amp line.  So shall now use one 60Amp isolation box with cartridge fuse and two counsumer units.  One consumer unit for upstairs and one for downstairs to give 20 MCBs with RCD security and 4 MCBs without.

I always think that running the refrigerator and freezers should be RCD free because I have seen where an outside light filament has gone and activated the RCD and the freezer has defrosted as a result.

 

So my question is this.

The Schneider MCBs come in 6, 10, 16, 20, 32, 40, 50 Amp.

 

I see that in Thailand they seem to connect lights and power (total 2000 watt) and run on 10 Amp MCB.

Then they might have a couple of 20 Amp MCBs for powerful things.

 

I am thinking of the following electric for the building, does this seem OK?

 

4 No 32 Amp MCBs to power four 6,000 watt water heaters/shower (one on each RCD bank).  6mm cable

I am well aware that if all were on that it would blow the 60 Amp isolation cartridge fuse but my intention is to only have two of the MCBs ever switched on at the same time (i.e only use two in real).

 

2 No 10 Amp MCBs  for Upstairs and Downstairs lights 1.5mm cable.

 

1 No. 10 Amp MCB  1.5mm cable for outside lights

 

6 No 20 Amp MCBs for power sockets in the house  2.5mm cable

 

1 No 20 Amp MCB for electric oven in kitchen 2.5mm cable

 

1 No 16 Amp MCB for an air conditioning unit (1200 watt) in the lounge. 2.5mm cable

 

1 No 16 Amp MCB (not on RCD) for refrigerator and freezer in kitchen. 2.5mm cable

 

1 No 10 Amp for alarms and CCTV on 1.5mm cable

 

1 No 10 Amp for water pump  1.5mm cable

 

1 No 32 Amp MCB outside (for DIY welding) 6mm cable  (MCB switched off except when using)

 

 

 

 

 

 

 

[Crossy]

18 minutes ago, Cashboy said:

I am thinking of the following electric for the building, does this seem OK?

I think you're on the right track. A couple of points:-

• Do you really need all those outlet circuits? There are few appliances outside the kitchen and workshop that run to more than an amp or two. Nothing to stop you running the cables and putting more than one on each MCB, you can split them off if tripping becomes a problem.
• Run 2 x 20A circuits to the kitchen (on top of the fridge / freezer circuit).
• Only one aircon? I suggest running cabling for air in all enclosed rooms, saves you doing it later. I'd put it on a 20A breaker (start current).
• Bung a 32A Commando socket on your "outdoor welding" circuit then Uncle Somchai won't plug the welder into a regular outlet.

 

[maxpower]

@Cashboy

 

We have 6A lighting and control circuits in Bangkok facilities. Spare breaker stock needs special order if we use exact replacement. ABB and Siemens keep a very unreliable small stock below 10A.

 

If you prefer to have separate 6A lighting circuits bring some breakers with you. My old condo was real fun when a CF fitting exploded on a 20A lighting circuit. Lots of entertaining flames and action before the breaker finally tripped.

 

My brothers Thai house was wired by a two German guys who used 6A breakers and 1mm cable for separate lighting circuits. Only internal lighting fridges and security are not earth fault protected.
 

[Cashboy]

4 hours ago, Crossy said:

I think you're on the right track. A couple of points:-

• Do you really need all those outlet circuits? There are few appliances outside the kitchen and workshop that run to more than an amp or two. Nothing to stop you running the cables and putting more than one on each MCB, you can split them off if tripping becomes a problem.
• Run 2 x 20A circuits to the kitchen (on top of the fridge / freezer circuit).
• Only one aircon? I suggest running cabling for air in all enclosed rooms, saves you doing it later. I'd put it on a 20A breaker (start current).
• Bung a 32A Commando socket on your "outdoor welding" circuit then Uncle Somchai won't plug the welder into a regular outlet.

 

Cheers for that.

I am just a simple accountant that has always wired up my own homes in the UK.

 

I don't think that I can get away with 12 MCBs so have to buy another Schneider Consumer Unit (100 amp mains swithch and two RCDs included) at £28  ( 1,204 bt ) and Schneider MCBs at £2.98   ( 128 bt) each including the VAT in the UK.

 

Yep, you are correct, the kitchen is about the only place that has load nowadays.

The rest is LED TVs, PCs and mobile phone chargers and Thailand fans.

 

Never gave any thought to the air conditioning needing "start current" but that won't cost much increasing to 2.5mm cable.

I was actually thinking about running cables for air conditioning as well as water supply in case I wanted to add air conditioning units.

I actually hope not to have to install any air conditioning units as I purposely have 3.4 metre ceilings downstairs and 3 metre upstairs , insulation in the roof, 150mm wide G-con blocks to disperse the heat with fans.  That is the theory anyway.

 

I don't expect to need hot water except a bit in the cold season (I have climatised to that initial cold water) and for washing up.

So can only see having one bathroom with the hot water heater on and maybe the kitchen hot water heater on.  I could probably drop a hot water supply to the kitchen from the bathroom upstairs to the kitchen sink and only have 3 water heaters.

 

I don't know how much hot water a 6,000 watt water heater produces.  I know that the starting cold water temperature in Thailand is about 19 C compared to the UK of 7 C so should get a lot more flow.  I just remember in my first UK apartment in the 80's that in the winter, I could urinate on myself and produce a larger flow and more heat than the Tritron T80 electric shower.

 

 

Edited February 1, 2018 by Cashboy

[richard1977]

On 2/1/2018 at 6:19 PM, Cashboy said:

6 No 20 Amp MCBs for power sockets in the house  2.5mm cable

is 20amp an ok breaker size to use with 2.5mm cable if the cable is chased into a masonry wall? (this is a studio condo, so only fairly small distances)?

 

the reason that i ask is that i saw this graphic:

can anyone translate the bottom right table?

eg. it says 2.5mm - 23amp - 17amp - 21amp .. i'm guessing these might be maximum breaker sizes under different circumstances, but i can't read it.

 

 

[Esso49]

Hi All,

 

I am a bit confused by all this.  I have just taken over an old property and wish to go about re-wiring safely in its entirety.  Being an old fart and coming from the UK I have read through countless threads on this forum regarding wiring of the consumer unit and I am still confused.   What I am used to seeing are the incoming  L and N feeds  going to the main breaker and then the L going to the RCB and on to the L busbar .   The N then goes to the N busbar.   There is a separate dedicated E busbar.  The incoming tails and earth to the grounding rod(s) are 16 mm.

 

Now that is what I am used to .

 

However is it me but I keep seeing something different in these posts ?  I see the incoming N connected to the earth busbar as well as the N connected to the earth busbar - that can not be right surely ? Also for a 15/45 Amp meter supply what size should the tails be if the house is around 50 metres from the meter location ?

[Crossy]

20 minutes ago, Esso49 said:

However is it me but I keep seeing something different in these posts ?  I see the incoming N connected to the earth busbar as well as the N connected to the earth busbar - that can not be right surely ? Also for a 15/45 Amp meter supply what size should the tails be if the house is around 50 metres from the meter location ?

 

Yes, this is correct, it's the Thai way of implementing TNC-S with MEN. If your supply back home is TNC-S you have that N-E link too, it's just out of sight in the service-head.

 

A 15/45 on a 50m run should be on 16mm² copper or 25mm² aluminium.

 

Note, if it's an old building in an existing village please check that MEN has been implemented in the area. Easiest way to check is to take a walk and look at the power poles, the neutral (usually the top wire) should be earthed every 3rd pole or so (look for a rod in the ground and a cable running down the pole).

 

If you're not sure about the MEN in your area wire it as TT with the incoming neutral straight to the main breaker. But do note that TT won't pass the initial PEA inspection for a permanent supply if you currently have a "construction" meter (easy to check, a construction supply is billed at about 8 Baht per unit).

 

EDIT Without a main service fuse to pull some of this work will need to be done live. Unwise!

I suggest that the first thing you do is (get a local sparks to) install a 2-pole main isolator in a separate box, this could be as simple as one of the "Chang" knife switches, cheap and the locals know how to hook them up. This is also now recommended in the UK (not the knife switch, that would cause a UK sparks to have palpitations).

 

[Crossy]

@richard1977 sorry, I missed your post back in March, must have been when the forum was having issues ?

 

The poster is translated here:-

 

[Esso49]

1 hour ago, Crossy said:

 

Yes, this is correct, it's the Thai way of implementing TNC-S with MEN. If your supply back home is TNC-S you have that N-E link too, it's just out of sight in the service-head.

 

A 15/45 on a 50m run should be on 16mm² copper or 25mm² aluminium.

 

Note, if it's an old building in an existing village please check that MEN has been implemented in the area. Easiest way to check is to take a walk and look at the power poles, the neutral (usually the top wire) should be earthed every 3rd pole or so (look for a rod in the ground and a cable running down the pole).

 

If you're not sure about the MEN in your area wire it as TT with the incoming neutral straight to the main breaker. But do note that TT won't pass the initial PEA inspection for a permanent supply if you currently have a "construction" meter (easy to check, a construction supply is billed at about 8 Baht per unit).

 

EDIT Without a main service fuse to pull some of this work will need to be done live. Unwise!

I suggest that the first thing you do is (get a local sparks to) install a 2-pole main isolator in a separate box, this could be as simple as one of the "Chang" knife switches, cheap and the locals know how to hook them up. This is also now recommended in the UK (not the knife switch, that would cause a UK sparks to have palpitations).

 

many thanks

 

[Crossy]

3 minutes ago, Esso49 said:

many thanks

No worries, it's what we do. 

 

Do post if you have any doubts as to what you have or what you are doing. Note that the Thai regs differ somewhat from the UK (no ring finals for a start) so some care is required.