Breaker Box suggestions.......

[r136dg]

On our new house construction I'll be supplying most of the electrical materials but will have the generals sub install most everything. I was wondering what breaker box I should start with, preferably something with a safety cut & can protect against any over voltage coming in. Here's a couple possibilities from Do Home but I think they're to small. It's a 3 bedroom (with ac's), 2 baths (with electric water heaters, exhaust fans & GFCI outlets), kitchen (with electric stove/oven) and attached garage (with several outlets for tools, light welding, ect). It'll be earthed from outside and probably in the trusses also.

Any advise appreciated!

[Crossy]

I would start with a bare DIN mount Consumer Unit (Brit-speak for breaker box), you can then populate it as you require. The advantage of using DIN mounts is that things like over-voltage units are readily available and can just be clipped in place and hooked up.

 

Start out with defining the circuits you need, power, lighting, aircon, water heaters. That will give you an idea of how many positions you need. Don't skimp in the kitchen, two power circuits there, but the rest of the house can likely be on two more.

 

Run a (32 or 40A) sub-main to the garage with another small CU in there.

 

Also, despite what the new UK regulations say, I would go with a plastic unit, less chance of a stray wire (they do happen) touching something that could go bang.

 

We have (three) 16 unit ABB System proM units, all the big box outlets should have them.

 

Have a look at this thread (there are many more)

 

 

[wpcoe]

What a timely walk down memory lane.  I'm renovating yet another condo I just bought and re-living that past thread reminded me of stuff I had forgotten.

 

The condo has a bona-fide Safe-T-Cut consumer unit, but has fewer breakers/circuits than I prefer, but there isn't much room where it is mounted to expand.  Safe-T-Cut sure wastes a lot of space in their CUs!

 

The one-bedroom condo with two air cons has each air con powered by a wire daisy-chained (and tacked to the wall surface) from the nearest wall socket.  I'd like to put each air con (new 12k BTU and 18k BTU inverters) on discrete circuits, but that would mean combining some other things.  Of course, the electrician (a Swede who works to European standards) wants to install a new gargantuan surface mount CU, but I'm trying to work within the confines of the existing recessed-in-the-wall Safe-T-Cut CU.

 

The labeling of the switches is mysterious and neither the electrician nor I are sure what the labels indicate.  First thing on Monday, all the gypsum ceilings will be ripped out and we can follow wires to see for sure what's on which circuit.

[r136dg]

I'm at several questions now (no big hurry, they just started the roof trusses). Forgive my limited electrical knowledge & the little I have is US terminology (seems irrelevant here), but I'm learning.

1: What's the difference between DIN's & CU's? It does seem CU's are partial or complete with breakers & that may be the only difference.

2: What is advised in front for surge protection (ie MOV) and where to get? Didn't see anything at the local Global. I've read threads here & have friends with no protection in front & have lost a lot from near lightning strikes, ect.

3: 50A Safe-T-Cut main breaker (as in attached pic of CU) or seperate Sate-T-Cut unit between the surge protection & DIN? I believe these are RCBO's and if anything trips them downstream you're left in total darkness. Would a standard 50A main or RCCB/RCD be a better choice with individual RCBO breakers to kitchen, bathrooms, outdoors, (anywhere close to moisture)?

4: Outlets in bathrooms? I know at the very least they're frowned upon here because of the way locals clean bathrooms. Probably best to avoid this but I'm curious. Note; I haven't seen any GFCI outlets here.

5: Crazier than #4, are there electrical inspections on new construction here before meters are installed?

Thanks!

 

[Crossy]

OK Here we go :)

 

1. CU (Consumer Unit) is Brit-speak for distribution board. These can be either DIN mount or Plug-in, the breakers from one type will not fit the other. A much larger range of devices is available in DIN making them more flexible if you want to do something a bit different.

 

Plug-in units are slightly quicker to install.

 

Both types are available as empty shells or populated with breakers. I've never seen a populated one with the combination of breakers that would be required

 

2. MOVs are available here from specialist outlets, but you're probably better mail ordering from aliExpress or Ebay. These are invariably DIN mount (you can get plug-in ones but $$$), so either an extra box required, or a DIN CU.

 

3. You are correct, a front end RCD/RCBO will leave you alive but in the dark.

 

Going for individual RCBOs would be better and more expensive. Or you could use a split board with two RCDs each driving half the house, if one trips the lights on the other stay on, leaving you alive and able to see. Either way your sparks is going to have to be rigorous in his correct use of neutrals, any neutral that's either shared between two circuits or connected to the wrong RCD will lead to headaches.

 

Whatever you do run an un-protected circuit for your freezer, nuisance trips are more than a minor issue if you come home to a de-frosted freezer.

 

4. Even as a Brit I'm happy to have outlets in wet rooms (they only became legal in the latest UK Regs), on an RCD they are just fine. GFCI (RCD) outlets are available here (Safe-T-Cut do them) but with RCD/RCBO in your CU you don't need them.

 

5, Yes, you will need to pass an electrical inspection before MEA / PEA will give you a permanent supply. It's pretty basic (visual inspection) but the man will want to see RCD, ground rod, and MEN wired in the approved manner.

 

EDIT This PEA document (in Thai but lots of pictures) should give you an idea of what the inspector will want to see. http://crossy.co.uk/Handy Files/groundwire.pdf note how the incoming neutral is routed via the ground bar. the Thai way of implementing MEN (similar to the NEC I believe).

 

Our inspection lasted an hour, 55 minutes of which was the inspector gassing with Wifey and asking who built our home :)

 

 

[r136dg]

Good yuks on that lengthy electrical inspection;-) Thanks much for all that helpful information Crossy! That put everything in perspective and I just ordered a  CUTLER HAMMER EATON CHSPT2ULTRA WHOLE HOUSE SURGE PROTECTOR  off ebay.

[Crossy]

@r136dg IMPORTANT!!! You did order a 220V version didn't you?

 

Looking at the illustrations here http://www.homedepot.com/p/Eaton-Whole-House-Surge-Protector-CHSPT2ULTRA-1/204761136 it does look like the trigger voltage is 600V which would be OK (we usually use 480V units) but the MCOV (Maximum Continuous Operating Voltage) is 150V L-N.

 

[Crossy]

By the way, to clarify the difference between DIN and plug-in breakers.

 

The photos in the first post show both types, top one (CEO) is DIN, bottom one (Schneider) is plug-in. 

[r136dg]

Yes Crossy, that's the one (2ULTRA) & same info from Eatons catalog.Hope it's compatable. Thanks again!

From ebay item specifics:  

Type:	Surge Protector	Model:	CHSPT2ULTRA
Surge Energy Capacity:	2820 J	MPN:	CHSPT2ULTRA
Voltage Compatibility:	240V	UPC:	786685436883

[Crossy]

The problem is that it's designed for the US 120V-0-120V (L-N-L) bi-phase system not the Thai 0-220V (N-L) single-phase system.

 

Also, looking more closely at the spec. the 600V is the clamping voltage during a surge (VPR), not the trigger voltage, I would not want to connect L-N of 220V to this unit.

 

It may be OK if you don't connect the neutral wire and just use the two phase connections, but how the indicators will behave and how well it will actually function in clamping surges is unknown.

 

Personally I'd try to cancel the order and get a unit designed for the type of supply we have here.

 

[r136dg]

Will do Crossy. Again, thank you for all the help & I'll post again when I nail down the proper unit.

[Crossy]

A unit like this would be the sort of thing you need (it's DIN mount by the way) https://www.aliexpress.com/item/CHNT-NU6-II-15KA-2P-surge-arrester-Lightning-arrester-Surge-protector-Household-arrester-Surge-switch/32608651488.html

 

 

ChiNT are a mid range Chinese manufacturer of electrical hardware so I would have no qualms using this as a front end device in my home (we have a similar unit from another Chinese

outfit which i actually bought retail in Shanghai).

 

If you are in a high-lightning area (outside the main cities) then you should also consider fitting smaller arrestors around your home particularly if you have sensitive technology.

 

I bought a bag of these 20mm / 10kA babies https://www.aliexpress.com/item/50Pcs-Lot-varistor-20D431K-10-20D431-430V-piezoresistor/32725332112.html

 

 

They are installed in all my light fittings (we are all LED, CFL or fluorescent with electronic ballasts), in the aircon units and behind the outlets that have electronics connected.

 

Obviously you need to sleeve the leads but they are significantly cheaper and have much better current capabilities than the plug-in units sold in Tesco and the like.

 

I will say I am slightly paranoid, we had a direct hit to our home about 4 years ago which fried a fair bit of technology.

 

EDIT Our roof after we were hit, if you zoom the image you can see where the strike tracked down the teak barge board before jumping to the (steel) roof structure. Scared the wits out of Wifey, it wasn't even raining at the time, evidently we upset the gods somewhere along the line.

 

 

[Cashboy]

I am hoping to re wire the house in Thailand when I arrive next week.

I have noticed that there appears to be no earth.

 

I am used to UK wiring.

 

I was looking at consumer unit, main switch and circuit breakers.

I have been looking at Schneider from Home Pro.

 

Here are my initial questions?

 

Main Switch:

I would like to upgrade mains into the house to highest singkle phase in Thailand.

Should I therefore put the 63 amp main switch in ( the price is the same for 63 amp or 50 amp).

 

Earthing:

If the mains coming in from the street are two wires only (live and neutral and no earth); can I connect the earth to the neutral as the earth in the consumer unit (fuse box) ?

Is that OK for regulations?

 

Cable:

Do Thai sell cables that are twin cable plus earth?

I ask that because the cable on the web site of Home Pro seems to be only two core by the looks of it.

 

Circuit breakers (MCBs and RCDs)

I see that Home Pro sell 10, 16, 20, 32, 50 amp circuit breakers and 16, 20, 32 amp RCD breakers.

 

Questions:

For mains plug sockets in the house; what amp circuit breaker should I use (16 amp, 20 amp) and to maximum number of sockets and what size cable?

For electric shower; what amp circuit breaker should I use?  would you recommend a 32 amp RCD  and what size cable?

For internal lights I assume 10amp; one circuit for upstairs and one for downstairs?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[Crossy]

@Cashboy

 

OK, some answers.

 

Following UK practice will stand you in good stead BUT no ring-finals all outlet circuits are radials and you will be expected to provide a link N-E at your incoming supply (MEN or PME in UK speak).

 

Main switch - This will actually be a 2-pole MCB (no service fuses here), the biggest single-phase supply is 30/100 (100A) but may not be available in all areas, this can have a 100A incoming MCB if you wish. Most of us have a 15/45 which is usually run on a 50A main breaker. You may need to upgrade the cables to your house, ask PEA what their requirement is when you enquire about the new meter.

 

What meter do you have at present? The rating will be on the dial somewhere.

 

Earthing - You need to provide a local rod and a link N-E in your consumer unit, Thailand is TNC-S with MEN. BUT if there's currently no N-E link I wouldn't install one unless you can see the neutral being grounded at every 3rd pole or so, if no N grounds leave the system as TT.

 

Cable - You won't find UK style twin and earth (with a bare earth) but flat cable with a green insulated ground core is available (look for VAF-G), you may need to hunt it out. Or wire in singles if you have existing conduit.

 

Breakers - 20A on outlet circuits and aircons (unless you have BIG aircons), 10A on lighting, 32A (or bigger) for your water heaters.

 

Wire your outlets in 2.5mm² as radials on 20A breakers, run two radials to the kitchen, but the rest of the house can be simply split upstairs / downstairs, modern homes don't have much in the way of high power items. I would stick to a maximum of 10 double outlets per radial, but there's no limit if you like loads of outlets, the cable is protected by the breaker.

 

Lighting in 1.5mm² on 10A breakers split as you see fit depending upon the size of your place.

 

Showers, run 4mm² on a 32A breaker, you're good for up to about 7kW, if you want bigger heaters then you need to go bigger on the cable and breaker.

 

If you have lights or outlets outside run them on their own breakers, then you can isolate them if the wet gets in.

 

RCD protection, up to you. Certainly for you water heaters and any outside lighting or outlets, and of course if you have a pool the pump etc needs an RCD (preferably a 10mA one). Whether you use individual RCBOs or a single front end RCD is down to cost, we have a mixture, one RCD for the aircon and water heaters, RCBOs for outlets, lighting is unprotected (except for outside lights).

 

I would have an unprotected outlet for your freezer, few things are worse than a freezer in a tropical environment that's been off for a week or two whilst you were away.

 

Have a look at this PEA document http://crossy.co.uk/Handy Files/groundwire.pdf in Thai but lots of drawings to see how you are expected to do things here.

 

Oh, and if you have a workshop / shed, run a nice meaty (at least 6mm²) sub-main to a small CU in the workshop.

 

 

[Cashboy]

On 2/14/2017 at 1:16 AM, Crossy said:

@Cashboy

 

OK, some answers.

 

Following UK practice will stand you in good stead BUT no ring-finals all outlet circuits are radials and you will be expected to provide a link N-E at your incoming supply (MEN or PME in UK speak).

 

Main switch - This will actually be a 2-pole MCB (no service fuses here), the biggest single-phase supply is 30/100 (100A) but may not be available in all areas, this can have a 100A incoming MCB if you wish. Most of us have a 15/45 which is usually run on a 50A main breaker. You may need to upgrade the cables to your house, ask PEA what their requirement is when you enquire about the new meter.

 

What meter do you have at present? The rating will be on the dial somewhere.

 

Earthing - You need to provide a local rod and a link N-E in your consumer unit, Thailand is TNC-S with MEN. BUT if there's currently no N-E link I wouldn't install one unless you can see the neutral being grounded at every 3rd pole or so, if no N grounds leave the system as TT.

 

Cable - You won't find UK style twin and earth (with a bare earth) but flat cable with a green insulated ground core is available (look for VAF-G), you may need to hunt it out. Or wire in singles if you have existing conduit.

 

Breakers - 20A on outlet circuits and aircons (unless you have BIG aircons), 10A on lighting, 32A (or bigger) for your water heaters.

 

Wire your outlets in 2.5mm² as radials on 20A breakers, run two radials to the kitchen, but the rest of the house can be simply split upstairs / downstairs, modern homes don't have much in the way of high power items. I would stick to a maximum of 10 double outlets per radial, but there's no limit if you like loads of outlets, the cable is protected by the breaker.

 

Lighting in 1.5mm² on 10A breakers split as you see fit depending upon the size of your place.

 

Showers, run 4mm² on a 32A breaker, you're good for up to about 7kW, if you want bigger heaters then you need to go bigger on the cable and breaker.

 

If you have lights or outlets outside run them on their own breakers, then you can isolate them if the wet gets in.

 

RCD protection, up to you. Certainly for you water heaters and any outside lighting or outlets, and of course if you have a pool the pump etc needs an RCD (preferably a 10mA one). Whether you use individual RCBOs or a single front end RCD is down to cost, we have a mixture, one RCD for the aircon and water heaters, RCBOs for outlets, lighting is unprotected (except for outside lights).

 

I would have an unprotected outlet for your freezer, few things are worse than a freezer in a tropical environment that's been off for a week or two whilst you were away.

 

Have a look at this PEA document http://crossy.co.uk/Handy Files/groundwire.pdf in Thai but lots of drawings to see how you are expected to do things here.

 

Oh, and if you have a workshop / shed, run a nice meaty (at least 6mm²) sub-main to a small CU in the workshop.

 

 

Thank you so much for that information.

So lets get this correct are you suggesting:

Put an earth rod in the ground and take an earth cable (what size) from the earth rod to the consumer unit (fuse box)?

Then connect the earth to the neutral in the consumer unit?  I never get the reason for that and don't do that in the consumer box (fuse box) in a UK house but raed this in Thai electrical guide.

 

The rest of the wiring from the consumer unit (fuse box) you stated sounds totally logical especially the fridge which I actually find wrong on a standard uk system with the two RCDs either of which can be knocked out by a filament in a bulb activating them off.

 

The house I am going to wire is the standard concrete pillars with block walls downstairs and timber upstairs with tin roof (Picture) with a live and neutral going into the house.

The supply in to the house is:The existing main fuse appears to be this.  The old ceramic fuse holder (centre) and not sure what the rest is.  Any idea?

Is there some kind of RCD there (on the left)?

And what is that with the red light on the right?

I am an accountant, not an electrician but wired up a few houses in the past as well as 3 phase in my warehouse.

 

The meter is outside on the road on a concrete pillar, quite normal from what I can see.

I gather looking at it that there is just a live and a neutral and hence in the UK I recall connecting the earth to the steel armour plating but also see that the electricity board connect the earth to the neutral before the meter.

 

 

 

 

 

 

 

[Crossy]

OK, that's a 5/15 meter, your first port of call needs to be PEA to get a meter upgrade to a 15/45, I doubt you'll need more. You should ask PEA if they want to see a bigger cable to the house (check what size the current one is), if not they'll probably do the upgrade without seeing the rest of the installation.

 

Go and do a quick survey of the power poles and see if the neutral is grounded anywhere (usually a bare conductor down every 3rd pole), if it is, then you should connect as MEN (N-E link in the CU), do it as shown in the Groundwire document I linked to above as this is the way an inspector will be looking for. If you don't see a neutral ground on the supply I would leave the N-E link off.

 

The thingy with the red light is a contactor of some sort, but there's no RCD on that system and barely any over-current protection.

 

[Cashboy]

16 hours ago, Crossy said:

OK, that's a 5/15 meter, your first port of call needs to be PEA to get a meter upgrade to a 15/45, I doubt you'll need more. You should ask PEA if they want to see a bigger cable to the house (check what size the current one is), if not they'll probably do the upgrade without seeing the rest of the installation.

 

Go and do a quick survey of the power poles and see if the neutral is grounded anywhere (usually a bare conductor down every 3rd pole), if it is, then you should connect as MEN (N-E link in the CU), do it as shown in the Groundwire document I linked to above as this is the way an inspector will be looking for. If you don't see a neutral ground on the supply I would leave the N-E link off.

 

The thingy with the red light is a contactor of some sort, but there's no RCD on that system and barely any over-current protection.

 

Thank you for that information.

 

So does 5/15 mean only 15 Amp ?  And if so what does the 5/ mean ?  and in your suggestion the 15/ in 15/45 ?

 

 

[Crossy]

A 5/15 is 15A max, 5A is the calibration current.

 

A 15/45 is 45A max, calibrated at 15A.

 

In reality meters are very robust and can handle a 100% overload pretty well indefinitely (with some loss of accuracy, bet they don't read low).