Safe-t-cut Consumer Unit/distribution Board.. Confused

[gouda]

Hello

Apologies for my lack of electrical expertise so this may be a dumb question

This consumer unit made by Safe-t-cut brand is installed at my friends house where I'm staying for a while, my question is ... does this contain an ELCB/RCD combined with the main breaker?

safe-t-cut-pattaya.com/en/Product/usa.html

To me it looks like it only has a double pole main breaker but I'm confused as doesn't "Safe-T-Cut" mean ELCB/RCD in Thailand? why would they write "safe-t-cut" on the box if it doesn't contain this feature?? or why does this 'safe-t-cut' brand make products without a safe-t-cut?

I thought ELCB's would come with a test button like these which state they are consumer units with GFI (aka RCD)

safe-t-cut-pattaya.com/en/Product/rcbo.html

so I am thinking that these are the consumer units with ELCB

There are currently 2 Hitachi electric showers installed, both with ELCB built in so I am hoping these are safe to use even if the

the consumer unit doesn't contain an ELCB. Have pressed the ELCB test button and it pops down the reset button as it says it should in the manual.

If it is the case of the main consumer unit not having an ELCB can I just replace it with a main breaker with an ELCB combined to get whole house protection for electricution?

Also not sure if the house is grounded, i know it would be good to have, but if not I am thinking the installing ELCB will help if anyone touches a live casing on an appliance

[Crossy]

I'm not sure if Saf-T-Cut (a brand name incidentally) make non-ELCB units for sale in Thailand, please post a photo of the unit you have. Yes it should have a 'test' button and all the ones I've seen also have an adjustable trip level (a bad thing IMHO).

Does the house have 3-pin outlets? If so there's a good chance it's grounded but still needs a visual and electrical check to verify (it's not unknown for 3-pin outlets to be installed without the ground being hooked up).

If your unit is not an ELCB you can't just install one in its place (as it would not provide over-current protection), you need to use a combined ELCB / MCB (RCBO) again a photo of what you have (with a resolution that allows us to read the markings) will speak better than all the questions we can ask.

Your showers MUST be properly grounded even with the ELCB protection. An ELCB will not save you from a shock (unless there is enough leakage to trip it before you touch anything), it will significantly reduce the chances of you dying from the shock you do receive.

Edited April 13, 2009 by Crossy

[gouda]

hi crossy

here are 2 pics of it

as you can see there is no test button

here are the pics i tried to link to above showing some of the range of units made by SAFE-T-CUT,showing the model installed and others with RCBO and adjustable trip level

if as i suspect it doesnt have ELCB protection can i replace the main breaker with an ELCB/MCB one of the same capacity, i think i read on your website that you shouldn't mix different brands of breakers or must the whole unit be replaced?

regarding the shower I thought that if its not grounded and becomes live, if someone touches it they become the connection to ground and the ELCB will trip as soon as a 30mA difference is detected between the live and neutral wires, so you'd receive a shock but the max current going through your body is 30mA, is that correct?

just wondering how severe is a 30mA shock?

one final thing, the shower has a plastic case, buttons, hose, head, but the water inlet hose and tap metal so are these what could become live? if these are changed to plastic parts would that be even better

many thanks for your help

[Crossy]

Ok, well that definately is NOT an ELCB, so you were right to be concerned. You should be able to get a combined 50A MCB / ELCB unit to replace that 50A incomer, or, if not, an external ELCB to go in front of your CU (may be an easier option).

Whilst it's not recommended to mix MCB brands, provided the unit fits without straining the internal connections there should be no issues.

There is no 30mA limit per-se, the current that flows is limited by your body resistance, just the ELCB drops out if it sees >30mA leakage. Even a 30mA shock definately hurts and if the ELCB doesn't trip (coz it's faulty) and there is no ground, you die

Only metallic parts have the potential to become live so a plastic tap would be safer, but to be honest, with an ELCB and a ground you really don't need to bother.

It is of concern to me that to many Thais the name "Safe-T-Cut" is synonymous with "ELCB" so there are likely many out there who believe they are protected when they are not!!

Do you know if the system is grounded or not yet?

Edited April 13, 2009 by Crossy

[trogers]

Safe-T-Cut RCBO unit has sensitivity settings - 6,10,20, and 30mA. I set mine to 20mA. The unit frequently trips when set to 6 and 10mA.

See this: http://www.safe-t-cut.com/eng/index.php?na...roduct&id=8

Edited April 13, 2009 by trogers

[trogers]

hi crossy

here are 2 pics of it

as you can see there is no test button

These are just fuse breakers - there is no ELCB

See this: http://www.safe-t-cut.com/eng/index.php?na...oduct&id=13

There is no sensitivity settings, and no spec. for trip time - 0.04 sec.

[gouda]

hi

yes, there are 3 pin sockets so i decided to look at the back to see if ground wire is present. I found a blue coloured wire in the earth terminal on several sockets.

I've just checked in the loft (or should i say sauna) regarding the wiring, all circuits from the consumer unit are 2 core 4mm2 plus a green ground.

For the 2 power circuits (lighting is joined to the same circuit) these 4mm wire are spliced to 2.5mm2, the green wire joined to blue and sometimes black wires.. so very confusing.

All the 4 air cons, 2 showers use 4mm2 wires on direct circuits with the green wire.

However I can't see a ground rod outside anyway. I presume that you should be able to see a wire from the eaves of the roof running to the ground rod and the only wires i can see into/out of the roof space are the 2 main live/neutral wires and a telephone wire.

So i suspect that the circuits have an earth but these are not connected to a ground rod.

regarding the main breaker i'll try to replace that with a combined elcb/mcb of the same size as putting a separate ELCB before the unit seems a bit dangerous

It is of concern to me that to many Thais the name "Safe-T-Cut" is synonymous with "ELCB" so there are likely many out there who believe they are protected when they are not!!

Exactly!, this was the source of my confusion, as the CU is made by the 'Safe-T-cut' brand and the house owners thought they were protected!

Safe-T-Cut RCBO unit has sensitivity settings - 6,10,20, and 30mA. I set mine to 20mA. The unit frequently trips when set to 6 and 10mA.

is this one of the external RCBO's that crossy mentioned, as its 21cm long... saw these already on the web but unsure how these hook up as only knew about the ones that go in the CU and external plug into the wall socket ones.

btw how do you post urls as i get a message saying "You are not allowed to post a URL."

cheers

[longball53098]

In my limited experience here the way these Thai "electricians" install a ground rod in a residential home is to drill a hole in the floor immediately below the location of the consumer panel, run the ground cable down a pvc pipe in the wall or if no pvc just cut a channel in the wall and then attach the cable to the rod and then drive it down below floor level and this gets cemented and tiled over never to be seen or serviced again.This is a major cost and time saver for the sparky. Especially the cable cost. They cut corners where there are no corners to save a baht.

[trogers]

regarding the main breaker i'll try to replace that with a combined elcb/mcb of the same size as putting a separate ELCB before the unit seems a bit dangerous

It is of concern to me that to many Thais the name "Safe-T-Cut" is synonymous with "ELCB" so there are likely many out there who believe they are protected when they are not!!

Exactly!, this was the source of my confusion, as the CU is made by the 'Safe-T-cut' brand and the house owners thought they were protected!

Safe-T-Cut RCBO unit has sensitivity settings - 6,10,20, and 30mA. I set mine to 20mA. The unit frequently trips when set to 6 and 10mA.

is this one of the external RCBO's that crossy mentioned, as its 21cm long... saw these already on the web but unsure how these hook up as only knew about the ones that go in the CU and external plug into the wall socket ones.

btw how do you post urls as i get a message saying "You are not allowed to post a URL."

cheers

I got my renovation contractor to add the external RCBO to existing fuse breaker box as I acquired old condos which already had a ground cable.

When you become a normal member and not a newbie, you will be allowed to post URLs.

[Crossy]

Gouda.

Pop the lid of your CU (power off, but watch the incoming supply), you should see a ground bar with the green wires going to it, a fatter green should go off to the rod somewhere. You may also find a N-E (MEN or PME) link.

Those singles should not be run naked, they are in invitation to rodents with potential shorts and fire issues, singles must always be run in conduit as their second line of protection.

I will say nothing about the twist-n-tape joints and random colour 'code'

The standard colour code used in Thailand is:-

Black - Live

White - Neutral

Green- Earth

You may find this page of use http://www.crossy.co.uk/wiring/Consumer.html

By the way, I would not attempt to install an ELCB yourself (the incoming tails will remain live).

Edited April 13, 2009 by Crossy

[Rimmer]

Just purely as a matter of interest I wonder whose MCBs Safe T Cut use as the cost of developing and manufacturing your own MCB/RCD range of product these days is close to building a new airliner.

I see they are quoting 10ka tested to US 2050 ?? Not familiar with that test, as far as I remember only IEC, NEMA and VDE standards apply to DIN rail mounted MCBS. But maybe it's all changed and now and the US use this type of breaker, But again I would not understand why with only 110volts to cope with.

I wonder if these really are the goods, will they really stand fault levels of 10KA. And is that 10KA tested to UL US standard in which case because the test methods are different they would be rated 3KA to BS. plenty enough but just interested!!

[gouda]

Hi all

hope you had a safe and happy Songkran...and have recovered from the hangovers..

Crossy, I have taken off the front panel and can see 8 green wires connected to the earth bar, as there are 8 circuits i presume there should be 9 wires connected if all the circuits are connected to the earth...

so does this look like the earth bar is not connected to an earth rod??

Do I have to follow each green wire in the attic to be certain or is there an easier way e.g. with a mulitmeter.... not that i have one over here

thanks in advance

[longball53098]

from what I see the green wires are connected to the neutral bus bar and there is a single solitary wire connected to the ground bus at the top

Anyone else see this?

And there are no ground/earth connections. Curious where this one black wire heads off to.?

[lopburi3]

Just purely as a matter of interest I wonder whose MCBs Safe T Cut use as the cost of developing and manufacturing your own MCB/RCD range of product these days is close to building a new airliner.

I see they are quoting 10ka tested to US 2050 ?? Not familiar with that test, as far as I remember only IEC, NEMA and VDE standards apply to DIN rail mounted MCBS. But maybe it's all changed and now and the US use this type of breaker, But again I would not understand why with only 110volts to cope with.

I wonder if these really are the goods, will they really stand fault levels of 10KA. And is that 10KA tested to UL US standard in which case because the test methods are different they would be rated 3KA to BS. plenty enough but just interested!!

Safe-T-Cut has been making units, and selling them, here in Thailand for over 30 years so expect they have the ability in-house.

[Crossy]

from what I see the green wires are connected to the neutral bus bar and there is a single solitary wire connected to the ground bus at the top

Anyone else see this?

And there are no ground/earth connections. Curious where this one black wire heads off to.?

YUP, agreed!!!

Houston Gouda, we have a problem!!

Lord knows what the installer was thinking!!

The wires from the bottom of the breakers (live) should be BLACK (not that I see any black wires [OK, there is one on the ground bar]).

The WHITE wires (neutral) should go to the neutral bar on the left.

The GREEN wires (ground) should go to the ground bar at the top (which should also have a link to a ground spike).

I suspect that the grounds from your outlets are connected to the neutrals somewhere (or more likely not connected at all)

The outlet shown earlier has black, white and blue wires (where do the black and blue wires go?)

If you just install an ELCB it may not stay in, or worse, may not trip at all

IMHO this installation is potentially dangerous and needs serious attention to render it safe, at a minimum those 'grounded' outlets need looking at to see where the grounds go (or don't go) to.

Edited April 16, 2009 by Crossy

[lopburi3]

I expect this is a "what was available cheap" wire code and would not trust any to be what they seem. Green might actually be ground. Your power company might be able to inspect and advise - they usually do know how it is supposed to be and, at least here in Bangkok, do inspect new work. Obviously that was not.

[Rimmer]

Just purely as a matter of interest I wonder whose MCBs Safe T Cut use as the cost of developing and manufacturing your own MCB/RCD range of product these days is close to building a new airliner.

I see they are quoting 10ka tested to US 2050 ?? Not familiar with that test, as far as I remember only IEC, NEMA and VDE standards apply to DIN rail mounted MCBS. But maybe it's all changed and now and the US use this type of breaker, But again I would not understand why with only 110volts to cope with.

I wonder if these really are the goods, will they really stand fault levels of 10KA. And is that 10KA tested to UL US standard in which case because the test methods are different they would be rated 3KA to BS. plenty enough but just interested!!

Safe-T-Cut has been making units, and selling them, here in Thailand for over 30 years so expect they have the ability in-house.

No they will not have the ability to develop an MCB they may have a license to assemble an MCB but I wonder from who.

[gouda]

thanks for all your comments and advice,

I'll recommend to my friends that they get it checked out by a qualified electrician and also add the ELCB