Installing Second-Hand Shower

[johnlk]

Hi all,

yesterday I bought a second-hand shower unit at the local market with the intention of installing it when we vist the gf's house next month.

The shower unit is a 5kw model, with no sign of any built-in ELCB, and it will be installed in her home which doesn't have an earth,

I am aware that I will need to use a grounding rod, but I am confused when it comes to ELCB's and RCD's etc.

Am I right in believing that a shower unit would need an ELCB and an RCD for "maximum" protection?

And, is it possible to buy a single unit that combines both these devices, here in Thailand, or will I need to buy each individually?

Any help is much appreciated.

[Crossy]

An ELCB and an RCD are actually the same thing. You'll need an RCD and an MCB (which provides overload protection) as well as some sort of grounding rod for maximum protection.

You can get an RCBO which provides both types of protection in one box, yes these are available in Thailand

At 5kW you'll need an MCB of 25A and wire it up with 4mm² cable, you could probably get away with 2.5mm² cable and a 20A breaker if you don't spend hours in the shower but do NOT put a 25A breaker on 2.5mm.

EDIT I'm really not convinced I'd buy a used heater, you really don't know what sort of life it's had.

[johnlk]

Great, thanks for the reply, my next question was about the sizes of the breakers and cables but you have answered them already.

Since posting I've had another look inside the casing and noticed something maybe of interest.

On the outside of the casing it states 5,500w, but on the inside, on a sticker on the small tank it says 4.5kw, so you might be right about a checquered history.

It was bought at a night market, so lighting wasn't that great, but the inside did look "as new", I mean no signs of leaks or worn cables.

Either way, once it's wired and plumbed-in it would be easy to replace it with a new shower if it didn't work.

[Crossy]

4.5kW will certainly be OK on 2.5mm cable although if it's a fairly long run and money's not dead tight I'd still use 4mm.

What size meter does your GF have, a regular 5/15 as found in rural areas will be right on it's limit (30% overload).

[johnlk]

I've no idea about meter sizes, but I can confirm she's in a village rather than a town/city.

I visited earlier this year and from memory the run for the cables is approximately 7 or 8 metres, and also she doesn't have any other heaters, machinery or appliances that take much load. Basically, it's just lighting and some power points.

I guess that as long as an RCBO is used it would cut out every time the load was too high, which would mean buying a less powerful shower.

[johnlk]

Made a visit to HomePro yesterday, and looked at all the different breakers.

The only one we saw that had RCBO printed on it was quite a large box, more like the size of a small consumer unit, and rated at about 60A. I guess it is for a large piece of machinery that needs it's own standalone feed?

The other breakers looked like they fitted into a consumer unit, and were not marked too clearly.

Today we are going to look in a more electrical-specific store to see if they have something smaller.

The one in HomePro was about 5000 baht, so I'm hoping we looked in the wrong store.

[JAS21]

Made a visit to HomePro yesterday, and looked at all the different breakers.

The only one we saw that had RCBO printed on it was quite a large box, more like the size of a small consumer unit, and rated at about 60A. I guess it is for a large piece of machinery that needs it's own standalone feed?

The other breakers looked like they fitted into a consumer unit, and were not marked too clearly.

Today we are going to look in a more electrical-specific store to see if they have something smaller.

The one in HomePro was about 5000 baht, so I'm hoping we looked in the wrong store.

Hang on for a half hour or so...Crossy asked me to help you...I bought some for our village green a while back and will go and photograph one for you. They are only small, you may have to go to a couple of HomePros as they all don't stock all the sizes. I guess that you will need a 10mA tripping level. I bought 30mA ones but only because all the wiring is in the ground. I'll wander across with my camera now.

[JAS21]

Made a visit to HomePro yesterday, and looked at all the different breakers.

The only one we saw that had RCBO printed on it was quite a large box, more like the size of a small consumer unit, and rated at about 60A. I guess it is for a large piece of machinery that needs it's own standalone feed?

The other breakers looked like they fitted into a consumer unit, and were not marked too clearly.

Today we are going to look in a more electrical-specific store to see if they have something smaller.

The one in HomePro was about 5000 baht, so I'm hoping we looked in the wrong store.

Hang on for a half hour or so...Crossy asked me to help you...I bought some for our village green a while back and will go and photograph one for you. They are only small, you may have to go to a couple of HomePros as they all don't stock all the sizes. I guess that you will need a 10mA tripping level. I bought 30mA ones but only because all the wiring is in the ground. I'll wander across with my camera now.

OK Photos attached, this is probably what you need. It is a HACO RCBO. You buy the breaker and also a plastic holder. Two pictures, one with the cover off. I can't remember the exact cost but about 700-800Baht. 10mA trip is safer, 30mA will make you jump but you should get over it. Just make sure that you install the shower as high as practical and the RCBO away from any chance of getting wet. Mine is not really high enough but there was a limitation. Ignore the panasonic timer.

[lopburi3]

Normally that is what is sold and used here as it is placed before the main distribution panel to protect all circuits in house. The individual outlet type units are not sold here AFAIK. They do have panels with built in RCCB main breakers and some are split into protected and unprotected sections.

[JAS21]

Maybe better size pictures

[Artisi]

Maybe better size pictures

John45

If this is the heater to which you have attached the RCBO, it was not necessary as the heater shown already has an inbuilt RCD (unless of course it not functional) - I believe that an MCB would have been sufficient.

[BuckarooBanzai]

OK Photos attached, this is probably what you need.

Having a metal sheathed shower hose is just asking for trouble. This is exactly what killed the two farangs here on vacation recently. Swap out with a rubber/vinyl hose. Although other failures were involved with their electrocution the metal sheathed shower hose was the path of the current that ultimately killed them.

Edited April 25, 2011 by BuckarooBanzai

[Crossy]

John45

If this is the heater to which you have attached the RCBO, it was not necessary as the heater shown already has an inbuilt RCD (unless of course it not functional) - I believe that an MCB would have been sufficient.

Actually no, an inbuilt RCD will not protect you from contact with anything bitey that happens before the RCD, so if the incoming live pops out and touches the metalwork you die

[wpcoe]

Having a metal sheathed shower hose is just asking for trouble. This is exactly what killed the two farangs here on vacation recently. Swap out with a rubber/vinyl hose. Although other failures were involved with their electrocution the metal sheathed shower hose was the path of the current that ultimately killed them.

Criminy, I never considered that factor. The shiny metal ones look so much prettier...

I know, "better safe than sorry," but with an ELBC, a cutoff switch like pictured above, and a ground wire leading to a stake, is there much of a risk to using a metal hose?

Below is a photo of what I currently have. The cutoff switch is outside the room. I still need to ascertain that the ground wire leading from the shower does in fact lead to a ground stake. Am I reasonably safe from electrocution with this shower?

[BuckarooBanzai]

Rubber Vinyl hoses come in many pretty colors! Seriously, reducing the risk of a life threatening situation, although possibly small, is more important than a small fashion statement in your shower.

Edited April 25, 2011 by BuckarooBanzai

[Crossy]

Agreed BB, indeed our shower has a nice 'silver' hose that's actually plastic, I've measured its resistance (dry) as well over 100Megs and it's nice and shiny

WP, you really need an external RCD as well as the built in one, you have no protection from contact with the incoming supply to the shower (like if the wire comes out and touches the metalwork).

[JAS21]

Maybe better size pictures

John45

If this is the heater to which you have attached the RCBO, it was not necessary as the heater shown already has an inbuilt RCD (unless of course it not functional) - I believe that an MCB would have been sufficient.

No, the pictures show the RCBO and Timer that I fitted to the lights and pumps in our Village Green..just to show him what he could use. I gave a picture of the shower heater that I installed to just say put it as high as possible. I have a SAFE-T-CUT (set at 15mA) covering everything except the Air Con Units..it's a new house. My electrical System is OK...Crossy checked it...anyway my background is HV up to 400KV so I have a rough idea as well!.

[powderpuff]

I am gonna roll up my pant legs & get involved. Not you Crossy cuz you're the man on this stuff.

Picture 1 I bought at Central Rama 3 out on the mall.

Picture 2 is a Siemens RCD I bought at the local wiring supply store. It was installed in the condo. Not for a hand shower but for a water heater tank.

I happened to be at Home Pro today & I saw what they stock in ABB very nice units. The 40 amp was 17xx baht & the 25 amp model was 19xx baht. Reason? The 40 amp jobby was on sale.

Good luck.

P.S. I am pretty sure the RCD will supply overload protection. I stand to be corrected.

[johnlk]

Thanks for all the additional help.

John45 you say yours is an RCBO but I can see "Earth Leakage Breaker" written on it. Doesn't that make it an ELCB?

Yesterday we did find a hardware shop that had a 30A breaker, clearly labelled as an ELCB, and also marked as 15mA. It was priced at 320 baht.

If this is just the protection that's missing from inside my shower, then I guess I would still need a second breaker fitted before or after it, and outside of the bathroom., or would this alone be sufficient?

Nobody seems to have heard of an RCBO, the best answer we got was to try HomePro, which we will try again today.

Sorry, all these abbreviations and different sorts of breakers are very confusing.

[JAS21]

Thanks for all the additional help.

John45 you say yours is an RCBO but I can see "Earth Leakage Breaker" written on it. Doesn't that make it an ELCB?

Yesterday we did find a hardware shop that had a 30A breaker, clearly labelled as an ELCB, and also marked as 15mA. It was priced at 320 baht.

If this is just the protection that's missing from inside my shower, then I guess I would still need a second breaker fitted before or after it, and outside of the bathroom., or would this alone be sufficient?

Nobody seems to have heard of an RCBO, the best answer we got was to try HomePro, which we will try again today.

Sorry, all these abbreviations and different sorts of breakers are very confusing.

I'm getting bored John, please have at look at your PMs.................Fit an RCBO in the shower electrical supply, preferably outside the shower area so that it protects the cable in the vicinity of the shower as well as the shower unit itself.

Edited April 26, 2011 by John45

[JAS21]

Was in Ngam Wong Wan HomePro this morning..Panasonic RCBO's 15mA at 500Baht including box. HACO 475Baht, box extra, 30mA trip only 475Baht.

[Crossy]

John45 you say yours is an RCBO but I can see "Earth Leakage Breaker" written on it. Doesn't that make it an ELCB?

The pictures are not very clear but if you zoom in you can see that they ratings include the text 'C16' indicating they are 16A 'C' curve breakers in addition to earth leakage.

EDIT From the Haco downloadable catalogue, SB-E16:- 16A, 230V, 30mA, trip time 0.03s provides protection from overload and earth leakage. It's an RCBO in all but name

They do 25, 32 and 40 Amp versions too.

[powderpuff]

So why were the ABB ones I saw at Home Pro so expensive? like 1700 baht?

[Crossy]

Possibly the ABB ones are made in Europe whereas the Haco ones are Thai or Chinese made?