Safe T Cut Unit Required?

[sitesurf]

Hello,

 

I have a relatively new Schneider consumer unit with RCD, (please see a slightly out of focus picture, apologies!) is it recommendable that I should fit a 'Safe T Cut' unit as well?

 

Thanks for any advice

[sometimewoodworker]

Safe-T-Cut is a well known brand of RCD/RCCB/RCBO.

 

If your current RCD (though it’s impossible see any details) is being tested at regular intervals and is still functioning there is no benefit to adding another.  If it is not functioning correctly then a replacement Schneider unit is a good idea.

 

Minimum life expectancy is probably about 5,000 operations, so monthly tests are recommended.

[sitesurf]

58 minutes ago, sometimewoodworker said:

Safe-T-Cut is a well known brand of RCD/RCCB/RCBO.

 

If your current RCD (though it’s impossible see any details) is being tested at regular intervals and is still functioning there is no benefit to adding another.  If it is not functioning correctly then a replacement Schneider unit is a good idea.

 

Minimum life expectancy is probably about 5,000 operations, so monthly tests are recommended.

much appreciated, I was not aware of that. Thanks

[Crossy]

 

Are you quite sure that box has an RCD/RCBO?

 

Does the main breaker (left side) have a "Test" button?

[sometimewoodworker]

1 hour ago, Crossy said:

 

Are you quite sure that box has an RCD/RCBO?

 

Does the main breaker (left side) have a "Test" button?

Agreed,I should have qualified my answer as the photo is so poor, we need a picture that actually shows details.

[sitesurf]

1 hour ago, Crossy said:

 

Are you quite sure that box has an RCD/RCBO?

 

Does the main breaker (left side) have a "Test" button?

Now that you ask, I am not sure, with a 100% certainty, that is has a RCD and I am not aware of any test button!

 

I thought (without any knowledge!) that the two separate gates to the left were RCD's or some kind of safety feature!...........I hope I haven't knocked you off your seat, with my ignorance!

 

I appreciate that the out of focus photo doesn't help.

 

I am away from home just now but have arranged for an electrician to come to the house on my return, next week...hence the question now, as I want to be prepared before he comes, so I know what to ask him to do, in relation to the consumer unit / safe t cut unit!

 

Any advice would be greatly appreciated

[Crossy]

Assuming you don't already have an RCD/RCBO (no Test button) you have two choices:-

• Install a Safe-T-Cut device on your incoming supply.
• Replace the main breaker (double unit on the left) with an RCBO.

Your sparks should be able to tell you if the Schneider / Square-D unit is readily available in your area.

 

Or you could order from Lazada https://www.lazada.co.th/products/schneider-breaker-qo250c10rcbo30-2p-50a-square-d-rcbo-i261502341-s402431551.html

 

Please try to post a better image of the box so we can verify that the above is the correct unit.

 

[sitesurf]

Thanks very much for the advice. I wil post a better picture next Tuesday (16th) when I get home. 

 

[sometimewoodworker]

4 hours ago, sitesurf said:

I thought (without any knowledge!) that the two separate gates to the left were RCD's or some kind of safety feature!.

It could be just a double pole MCB so isolating both incoming line and neutral.
 

That could be thought of as a safety feature if you try thinking very hard. ????  

[bluejets]

10 hours ago, sometimewoodworker said:

 

That could be thought of as a safety feature if you try thinking very hard. ????  

 

Not in an MEN installation.

[sometimewoodworker]

36 minutes ago, bluejets said:

 

Not in an MEN installation.

That rather depends on the installer and installation along with the position of the switch.

 

Though I don’t see why a MEN install makes it any less safe

[sitesurf]

On 3/10/2020 at 7:50 PM, Crossy said:

Assuming you don't already have an RCD/RCBO (no Test button) you have two choices:-

• Install a Safe-T-Cut device on your incoming supply.
• Replace the main breaker (double unit on the left) with an RCBO.

Your sparks should be able to tell you if the Schneider / Square-D unit is readily available in your area.

 

Or you could order from Lazada https://www.lazada.co.th/products/schneider-breaker-qo250c10rcbo30-2p-50a-square-d-rcbo-i261502341-s402431551.html

 

Please try to post a better image of the box so we can verify that the above is the correct unit.

 

Hi sometimewoodworker and crossy... do these pictures help in making an assessment re safe -t cut and if possible....additionally, I would like to also install some form

of  lightning / surge protection?

 

many thanks for any advice 

[sitesurf]

On 3/10/2020 at 7:50 PM, Crossy said:

Assuming you don't already have an RCD/RCBO (no Test button) you have two choices:-

• Install a Safe-T-Cut device on your incoming supply.
• Replace the main breaker (double unit on the left) with an RCBO.

Your sparks should be able to tell you if the Schneider / Square-D unit is readily available in your area.

 

Or you could order from Lazada https://www.lazada.co.th/products/schneider-breaker-qo250c10rcbo30-2p-50a-square-d-rcbo-i261502341-s402431551.html

 

Please try to post a better image of the box so we can verify that the above is the correct unit.

 

Hi sometimewoodworker and crossy... do these pictures help in making an assessment re safe -t cut and if possible....additionally, I would like to also install some form

of  lightning / surge protection?

 

many thanks for any advice 

On 3/10/2020 at 7:50 PM, Crossy said:

Assuming you don't already have an RCD/RCBO (no Test button) you have two choices:-

• Install a Safe-T-Cut device on your incoming supply.
• Replace the main breaker (double unit on the left) with an RCBO.

Your sparks should be able to tell you if the Schneider / Square-D unit is readily available in your area.

 

Or you could order from Lazada https://www.lazada.co.th/products/schneider-breaker-qo250c10rcbo30-2p-50a-square-d-rcbo-i261502341-s402431551.html

 

Please try to post a better image of the box so we can verify that the above is the correct unit.

 

 

On 3/10/2020 at 7:50 PM, Crossy said:

Assuming you don't already have an RCD/RCBO (no Test button) you have two choices:-

• Install a Safe-T-Cut device on your incoming supply.
• Replace the main breaker (double unit on the left) with an RCBO.

Your sparks should be able to tell you if the Schneider / Square-D unit is readily available in your area.

 

Or you could order from Lazada https://www.lazada.co.th/products/schneider-breaker-qo250c10rcbo30-2p-50a-square-d-rcbo-i261502341-s402431551.html

 

Please try to post a better image of the box so we can verify that the above is the correct unit.

 

 

[Crossy]

OK you have NO earth leakage protection so you should follow the suggestions in post #7 above.

 

You will need the 63A Safe-T-Cut or Schneider RCBO.

[sitesurf]

1 hour ago, Crossy said:

OK you have NO earth leakage protection so you should follow the suggestions in post #7 above.

 

You will need the 63A Safe-T-Cut or Schneider RCBO.

Thank you very much for your advice

[sometimewoodworker]

2 hours ago, sitesurf said:

I would like to also install some form

of  lightning / surge protection?

@Crossy will have the best information on that I have it in my DIN rail box but some Schneider equipment is plug in not din rail

 

this is the schematic for my incoming supply with thanks to @Crossy for the design.

 

and this is the box

the red one is the surge arrester  

[Metropolitian]

On 3/10/2020 at 2:36 PM, sitesurf said:

A few, and good, advices/responses are already given especially by crossy and sometimewoodworker.

 

First what I notice from your photo is that all the cabling is done inside the wall.

This will give the safeTcut solution lesser attractive both cosmetically and technically.

We don't know if the incoming wires to the main breaker is long enough to be bypassed to the additional safeTcut device, and then it need drilling (beware the cables!) and having an extra box beside the Schneider box.

 

The best solution is to focus to the box itself.

This has two options, an RCBO as main which then protects everything and yes everything will be turned off when leaking occurs.

The other solution is RCBO at the breaker side, you can then choose which groups you want to have protection and some groups left unprotected.

This can be pricey if you want all breakers changed, then the choice is whether you want everything dark or only the group affected.

 

For this box there is plug in surge arrester available.

 

  

Picture 1: Surge Arrester

Picture 2: The small breaker is the sub breakers and the 2nd breaker is the main breaker. (The white breakers are for other box, din-rail, same as sometimewoodworker has.)

 

 

 

 

 

 

 

 

 

[thaibeachlovers]

On 3/10/2020 at 9:13 PM, sometimewoodworker said:

Safe-T-Cut is a well known brand of RCD/RCCB/RCBO.

 

If your current RCD (though it’s impossible see any details) is being tested at regular intervals and is still functioning there is no benefit to adding another.  If it is not functioning correctly then a replacement Schneider unit is a good idea.

 

Minimum life expectancy is probably about 5,000 operations, so monthly tests are recommended.

What does 5,000 operations mean. My Safe T Cut saved my life twice in a couple of years- I can't imagine it doing so 5,000 times.

[sandrabbit]

3 hours ago, Crossy said:

OK you have NO earth leakage protection so you should follow the suggestions in post #7 above.

 

You will need the 63A Safe-T-Cut or Schneider RCBO.

Schneider is good gear, you can buy a 63A Schneider rcd in Thaiwatsadu, Homepro, Global etc and I think it's just under 4k baht. It's plug in (with cables disconnected pull the bottom out). Incoming supply comes in from the bottom so it has to be isolated although I know many Thai electricians would take the chance. Schneider gear is European standard (industry) so I would prefer that over safe-T-cut. 

[VocalNeal]

My 2c.

 

You can call/contact Safe T Cut and they will come to your house and install one.

[sandrabbit]

Schneider is part of Square D group and this is what you need, if you were in Rayong I would sell it to you for a reasonable price. Please ignore the pictures from Metropolitian (no offense intended) as this is the part you need. I have Schneider in my house, had it in my condo but the insulation resistance of the wiring was bad and the rcd would trip but the guy rewiring really didn't like the Schneider board so with my wife's advice I let him replace the dist board when rewiring even though the Schneider board was technically better & safer. I discovered the insulation resistance was bad when I fitted this very rcd, even with a multimeter it was around 200K ohms in some circuits. 

 

 

[sandrabbit]

57 minutes ago, thaibeachlovers said:

What does 5,000 operations mean. My Safe T Cut saved my life twice in a couple of years- I can't imagine it doing so 5,000 times.

I agree, unless you have the data sheet and even then you can't quote mean time between failures so it could trip with low load or high load and the contacts damage from disconnection would be different every time. Don't test with high loads, save your contacts. I've seen circuit breakers, contactors etc have welded contacts under fault conditions and then it goes up to the next level of protection which involves more current to trip which can lead to fires. 

[Metropolitian]

28 minutes ago, sandrabbit said:

Schneider is part of Square D group and this is what you need, if you were in Rayong I would sell it to you for a reasonable price. Please ignore the pictures from Metropolitian (no offense intended) as this is the part you need. I have Schneider in my house, had it in my condo but the insulation resistance of the wiring was bad and the rcd would trip but the guy rewiring really didn't like the Schneider board so with my wife's advice I let him replace the dist board when rewiring even though the Schneider board was technically better & safer. I discovered the insulation resistance was bad when I fitted this very rcd, even with a multimeter it was around 200K ohms in some circuits. 

You stand corrected, Schneider is the parent group of Square D since 1991, this make Square D now a part of the Schneider Electric SE group.

 

There is no reason to ignore the picture in my post and even to say that, the picture shows accurate what the breakers that SE offers are.

The OP need breakers from the series QOvs, which fits in his new 'classic' D Square box.

 

It is a pity that the box in your home was replaced, it is as you said a technically better and safer box.

I also have one D Square box (Old series, same as your rcbo breaker is) which is not the main CU anymore but still decently in use at the 2nd floor.

 

Another box here which is din-rail for it modulairity act now as the Main CU and from this connected to one RCBO breaker going to the Square D box.

Three RCBO main breakers, all seperate groups, gives me some peace that when there is an 'leak' we are not totally blackened out.

 

[sometimewoodworker]

7 hours ago, thaibeachlovers said:

What does 5,000 operations mean. My Safe T Cut saved my life twice in a couple of years- I can't imagine it doing so 5,000 times.

It means that you can test trip the RCCB every month, as you should, for the rest of your life (even if you have just been born), and It will still be well within it’s designed life.

[kamalabob2]

If you open the current Schneider catalog you will see the Schneider version of the "Safe-T-Cut" box the PEA is recommending. The Op could walk into a PEA office if he was in Thailand and they can show him what they want his electrician to install. Schneider makes the product, it is in the catalog and any Schneider dealer can order it from one of the two Schneider distributors in Thailand. I'll scan the page and post it later in the week.  Schneider has at least one technical staff who understand and speak English at the Bangkok office. He was able to give me exact model numbers of circuit breakers I needed for an installation in Buriram.