Water heater installation, what could go wrong ?

[Crossy]

An RCD or RCBO device will save you from death in the event you touch or otherwise contact a live wire (via a faulty appliance for example). This is particularly important in Thailand where the electrical installations can be somewhat suspect (particularly grounding).

 

[lopburi3]

21 minutes ago, myjawe said:

 

hello, I have no test button anywhere. Everything is working fine. Why adding something to the electric system, and what ? thank you so much.

 

 

 

 

 

This is what we are talking about and most Thai will know this brand as has been made here for 40 years now.  It continually monitors hot and neutral lines to make sure the same amperage on both - a slight difference will immediately cut power and normally save your life if you are getting a shock.  As most outlets here are not grounded, or suspect, it is a very good protective measure to have such a unit.  There are many other brands and all, if designed for home safety use, should work about the same.  As said there normally is a built in unit for water heaters which protects user. 

Edited May 19, 2019 by lopburi3

[Snackbar]

Disgusting piece of equipment. Offers zero protection to vulnerable or uninformed consumer. 

 

Not recommended, it is open to abuse by unscrupulous chancers.

[lopburi3]

11 minutes ago, Snackbar said:

Disgusting piece of equipment. Offers zero protection to vulnerable or uninformed consumer. 

 

Not recommended, it is open to abuse by unscrupulous chancers.

Not sure what you are talking about but RCBO are a proven safety system and have been in use for decades (and saving lives) and for wet rooms are required by many countries.

[Beggar]

2 hours ago, Snackbar said:

Disgusting piece of equipment. Offers zero protection to vulnerable or uninformed consumer. 

 

Not recommended, it is open to abuse by unscrupulous chancers.

For sure it is not perfect and if you have a better more safe idea please let us know. 

[MadMuhammad]

On 5/17/2019 at 10:46 AM, Beggar said:

In respect of putting the water heater and a hair dryer to the same switch. Both could be switched on at the same time. So you have to make sure that the cable going to the switch supports this wattage and also make sure that the fuse protecting this cable fits. 

Not if you come off of the line side of the switch to the outlet ????????

Good advice on the cable & fuse sizing. Furthermore, if you break gauge from the water heater feed to the outlet you need to size the breaker to that of the smaller cable 

[Crossy]

9 hours ago, Snackbar said:

Disgusting piece of equipment. Offers zero protection to vulnerable or uninformed consumer. 

Not recommended, it is open to abuse by unscrupulous chancers.

 

You do seem to have a bit of a thing about RCD/RCBO units, is it a particular brand (Safe-T-Cut perhaps) or these devices in general?

 

Perhaps you could enlighten us, these things (like seatbelts) are by no means perfect, but they are proven to increase the chance of survival from both direct and indirect contact with live items.

 

[bankruatsteve]

11 hours ago, rwill said:

But the bathrooms in America are not designed for the whole floor to be wet.  

Totally irrelevant.  Water is not a requirement for contact or fault to ground.

[Snackbar]

Single pole RCD B1500.00 - simple to install in 5 mins, trips to identify earth leakage - perfect.  Total cost - B2000.00

 

Safety Cut B5000.00 - 3-4 hours to install, doesn’t identify which circuit  has a fault. Can be turned off, manipulated by the unscrupulous. Total cost - B8000.00 +++

 

Which one is a local ‘spark’ going to recommend?

Edited May 20, 2019 by Snackbar
Some people are unaware of the obvious.

[Crossy]

@Snackbar now I understand (and I am in agreement) ????

 

The modern Safe-T-Cut units no longer have the hazardous "direct" or "bypass" function, I don't think I've seen one set to anything other than 30mA so the more sensitive options are a waste of money.

 

Don't forget your single-pole RCBOs (not just RCD) are 1,500 each, and you need one per circuit you want to protect. Absolutely the best solution but they can be a real pain to get working if you have an existing system with zillions of borrowed neutrals ????

 

A single front-end RCBO replacing your existing main breaker (or an RCD added to the existing MCB) is also a solution if you have room in your board to install it. Same "one out, all out" problem as the Safe-T-Cut but better than half the price.

 

The Safe-T-Cut (expensive) has the advantage that it's a simple to install box, no mucking about with the existing wiring (apart from removing the MEN link in the board if one exists).

 

A good halfway-house which is popular in the UK, would be a split or dual-RCD board. Split the circuits between two RCDs so if you have a failure you only lose half the supply.

 

 

[Snackbar]

What is a ‘browned neutral’ 

 

Not mentioned in here

[Snackbar]

Not here either

[Snackbar]

Nope

[bankruatsteve]

10 minutes ago, Snackbar said:

What is a ‘browned neutral’ 

 

Did you mean "borrowed"?  I know the US NEC has (or at least used to have) discussion specific for that.  Actually, there is one case where it is required:  For kitchens, there must be L from the phase left and L from the phase right (2 circuits) with N shared.  That is the only exception.

Edited May 20, 2019 by bankruatsteve

[Crossy]

9 minutes ago, Snackbar said:

What is a ‘browned neutral’ 

Not mentioned in here

 

It's not mentioned in my post either, go back and read it again (no I have not edited it).

 

You probably won't find it in BS7671 or the OSG either.

 

You will however find it mentioned often on the IET forums.

 

[RJRS1301]

Indeed, what could go wrong??

Water, electricity.

Check your insurance policies and wear rubber soled shoes

Goodness sake call a qualified electrician and be sure and safe and alive

 

[Crossy]

1 minute ago, RJRS1301 said:

Goodness sake call a qualified electrician and be sure and safe and alive

 

If you can find a good, qualified domestic sparks in Thailand make sure to keep his number, he is a rare breed indeed.

 

There ARE many good and qualified electricians here, but they're all employed in O&G or the mega-projects and earning pots.

 

[wgdanson]

On 5/17/2019 at 10:33 AM, Beggar said:

I always connect live and neutral correctly. Otherwise something that seems to be switched off still can be under power. I never care about cable colors but always check myself what is the live and what is the neutral wire. 

How do you do that, lick your finger and touch the wire. Whichever one tingles.....that's LIVE!   LOL

[sometimewoodworker]

2 hours ago, bankruatsteve said:

Did you mean "borrowed"?  I know the US NEC has (or at least used to have) discussion specific for that.  Actually, there is one case where it is required:  For kitchens, there must be L from the phase left and L from the phase right (2 circuits) with N shared.  That is the only exception.

But that is only for the arcane and weird wiring and electrical used in the North American continent (2 countries) and AFIK no other countries (195 countries) world wide. 

 

Also a borrowed neutral refers to 2 or more circuits that share a neutral, AFIK the US feeds 240v with a single 4 wire circuit PL, PR, N & E that in the distribution panel is required to use a single 2 phase breaker. So this not a case of having a borrowed neutral.

2 hours ago, Snackbar said:

What is a ‘browned neutral’ 

 

A good reasonably simple explanation of what it is and why you don't want it

 

 

 

Edited May 20, 2019 by sometimewoodworker

[Beggar]

1 hour ago, wgdanson said:

How do you do that, lick your finger and touch the wire. Whichever one tingles.....that's LIVE!   LOL

My goodness. Never saw things like in the photo? The cheapest are the two screw drivers. Without them I would not do anything with electricity... 

[wgdanson]

15 minutes ago, Beggar said:

My goodness. Never saw things like in the photo? The cheapest are the two screw drivers. Without them I would not do anything with electricity... 

Did you not notice I put LOL after my post. That means it is meant as a JOKE.

[xtrnuno41]

This is a RCD, not for protecting wiring as a fuse, but safety.

It can handle 40 Amps through, but when there is a difference (Amp leakage between the two wires) of 30 mA.

It shuts down. THis is a din rail model, you also have bus systems.

Also you have them in several varieties, like 50 Amps, 63 Amps through.

sadly you refuse to put a pic of your system on this page, so no one can tell what.

 

 

This is a RCBO, it is included with a circuit breaker. You can see on the device, this one is a 16 Amp B-characteristic (B16) with a 30 mA (0.03 )safety switch (RCD). You also have them with C-characteristic. But B is better, it switches off faster (lower in shortcut power) in case of shortcut.

Of course you have them in many varieties, like B6, B10, B16, B25, B and so on, also the C's. But for home situation better to use B-characteristic switches. Again this one is din rail mounted.

[Beggar]

21 minutes ago, wgdanson said:

Did you not notice I put LOL after my post. That means it is meant as a JOKE.

I forgive you 1 time.

[wgdanson]

This is getting me worried, and I just checked to find that I do not have a RCBO. Looked on Lazada, Safe T Cut 63 amp jobby Bht 2800. Others of unknown origin Bht 400 ish. Which one do I go for?

[atyclb]

42 minutes ago, xtrnuno41 said:

This is a RCD, not for protecting wiring as a fuse, but safety.

It can handle 40 Amps through, but when there is a difference (Amp leakage between the two wires) of 30 mA.

It shuts down. THis is a din rail model, you also have bus systems.

Also you have them in several varieties, like 50 Amps, 63 Amps through.

sadly you refuse to put a pic of your system on this page, so no one can tell what.

 

 

This is a RCBO, it is included with a circuit breaker. You can see on the device, this one is a 16 Amp B-characteristic (B16) with a 30 mA (0.03 )safety switch (RCD). You also have them with C-characteristic. But B is better, it switches off faster (lower in shortcut power) in case of shortcut.

Of course you have them in many varieties, like B6, B10, B16, B25, B and so on, also the C's. But for home situation better to use B-characteristic switches. Again this one is din rail mounted.

 

 

is rcbo the same as . gfi ?

[Crossy]

1 minute ago, wgdanson said:

This is getting me worried, and I just checked to find that I do not have a RCBO. Looked on Lazada, Safe T Cut 63 amp jobby Bht 2800. Others of unknown origin Bht 400 ish. Which one do I go for?

 

I would go mid range. If you have a DIN mount distribution box, and it has space, you can add a brand name (ABB) RCD for a k Baht or so.

 

[Crossy]

1 minute ago, atyclb said:

is rcbo the same as . gfi ?

 

No, an RCD is the same as a GFI. It has no over-current protection.

 

The problem is they look the same to the untrained eye.

[atyclb]

Just now, Crossy said:

1 minute ago, atyclb said:

is rcbo the same as . gfi ?

 

No, an RCD is the same as a GFI. It has no over-current protection.

 

does a gfi on the water heater line protect against electrocution?  

[Crossy]

23 minutes ago, atyclb said:

does a gfi on the water heater line protect against electrocution?  

 

It will significantly reduce the danger of your dying from direct (grab a live wire) or indirect (faulty heater with no ground) contact, there are no guarantees in this world.

 

The classic 30-30-30 (30V, 30mA, 30ms) rule means that something like 90% of the population will survive (that's why the 25kV final-anode voltage on a CRT TV is limited to 25mA), the old, young or infirm may have a lower tolerance and die anyway ????

 

An RCD (GFI, ELCB or whatever you want to call it) is no substitute for a decent earth/ground on an appliance (water heater) that needs it. Together they provide a very reliable safety system, each alone is more of a lottery.

 

 

[bankruatsteve]

2 hours ago, sometimewoodworker said:

But that is only for the arcane and weird wiring and electrical used in the North American continent (2 countries) and AFIK no other countries (195 countries) world wide. 

 

Also a borrowed neutral refers to 2 or more circuits that share a neutral, AFIK the US feeds 240v with a single 4 wire circuit PL, PR, N & E that in the distribution panel is required to use a single 2 phase breaker. So this not a case of having a borrowed neutral.

A good reasonably simple explanation of what it is and why you don't want it

 

I don't know why the US came up with split phase (after Edison's DC fiasco) but I wouldn't call it arcane.  By definition the example I gave would be a "borrowed" neutral and you are correct that it is not that case but rather a shared neutral.  In retrospect I should not have mentioned that case as it has no relevance to anything here.  As for US decision to go with split phase I have no idea why.  Maybe it is good for delivering power with minimum cost?  I don't know but that's the way it is.