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Posted By: electure Bathroom Electric - 10/27/04 10:19 PM
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There are often discussions as to what electrical practices are acceptable in bathrooms. Recently, one such discussion focused on whether or not to place light switches within bathroms.
And who can forget the photos of switches, receptacles, track lights, and even panels within the bath/shower enclosure?

On a visit to Israel, I found that the common practice there was to mount the water heater within the shower enclosure; the enclosures are small enough that the water heater gets well rinsed with each shower. The electric power connects in the pan under the heater. Interestingly enough, the switches for the heater, as well as the light, are located outside the bathroom for "safety."
Since many of these heaters come from panels that have replaceable element (wire-type) fuses, I assume that there is no GFI-type device.

The photo shows one such heater. The large red lable with a caliper-like symbol is the "Teken," the mark of the local UL-type agency.
I heard many accounts of these heaters rupturing, but none of any shocks.


renosteinke (John)


[Linked Image]

edited 'cause I goofed...S


[This message has been edited by electure (edited 10-27-2004).]
Posted By: pauluk Re: Bathroom Electric - 10/28/04 10:19 PM
Thinking about it, I suppose this isn't too far removed from the instant electric showers which are common in Britain, although admittedly ours are plastic cased and we have the feed coming in through the rear, not looped like this within the cubicle!

It's quite incredible really that our rules allow a 240V-powered heater inside the shower compartment, but not a normal receptacle located safely out of harm's way over a basin.

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Since many of these heaters come from panels that have replaceable element (wire-type) fuses, I assume that there is no GFI-type device.
Could be a main GFI separate from the panel, as is common in the U.K. and Europe.



[This message has been edited by pauluk (edited 10-28-2004).]
Posted By: John Steinke Re: Bathroom Electric - 10/29/04 01:33 AM
Quite right, Paul. I must say that, at the time, I was not in the trade, and had no idea of what I was looking at.
Posted By: electure Re: Bathroom Electric - 10/29/04 11:03 AM
John, do you remember what type of wiring method was used to connect this heater?

It looks almost like cord, or some type of loom.
Posted By: John Steinke Re: Bathroom Electric - 10/29/04 11:15 PM
The typical wiring method in Israel is to use a rotohammer to chisel irregulat trenches in the block wall, insert 'smurf' tube and boxes, then plaster over. The wires are similar to THHN, but are capped by little terminal strips - look like but splices with screws. The appliance wires are then connected to the free screw. What you see is almost certainly a fabric-wrapped appliance lead.
Great eyes!
Posted By: pauluk Re: Bathroom Electric - 10/30/04 05:54 PM
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capped by little terminal strips - look like but splices with screws.

John,
Are they anything like these British strip connectors?

[Linked Image from tlc-direct.co.uk]
Posted By: iwire Re: Bathroom Electric - 10/31/04 10:30 AM
I use those connectors all the time for fire alarm systems. One of the states I work in will not allow wire nuts for fire alarm work.

They are also handy when space is tight, they take up less space and wire then wire nuts.

A great help if a wire is short.
Posted By: John Steinke Re: Bathroom Electric - 11/02/04 01:38 AM
Yes, Paul, those are them! Typically, sections are broken off and used as needed.
Posted By: thiggy Re: Bathroom Electric - 11/02/04 12:54 PM
I noted that type of setscrew connector when I visited friends in Germany a while back. They explained that the practice there was when you move, you take your light fixtures with you. Are those types of connectors permissable for use in residential applications in lieu of wire nuts in this country (US)?
Posted By: pauluk Re: Bathroom Electric - 11/02/04 01:21 PM
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Yes, Paul, those are them! Typically, sections are broken off and used as needed.
We still colloquially refer to these as "Choc blocks" or "chocolate blocks," because years ago the plastic was most often black or dark brown rather than translucent (although other colors such as blue and white were available as well).

With the older, more solid types you generally needed to use a sharp knife to cut off however many connectors were needed, but with the newer types pictured above you can just twist them off.
Posted By: Texas_Ranger Re: Bathroom Electric - 11/03/04 06:02 PM
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The typical wiring method in Israel is to use a rotohammer to chisel irregulat trenches in the block wall, insert 'smurf' tube and boxes, then plaster over. The wires are similar to THHN, but are capped by little terminal strips - look like but splices with screws.

Exactly the way you do it in most continental European countries. However, the trenches (if horizontal) should be within 1ft from the finished floor or ceiling, so it's not all irregular.
In Germany there are two types of set-screw connectors. The type in the picture is only allowed to be used for hooking up light fixtures etc. Then there's a second type with just one row of screws, which is used for fixed wiring inside boxes, just like wire nuts in the US. Here in Austria you're allowed to use the pictured style of choc blocks for fixed wiring, but you may only use one set of screws (or strip the wires long enough to get them under both screws from one side). You're not allowed to insert wires from both sides since that would reduce the cross-section of the wire and thus pose a fire risk. At least that's what I was told.
@Paul: for the real old bakelite ones you'd need a hack saw! And the even older ones were made of porcelaine.
When you move out of a house you usually take the light fixtures and leave the choc blocks in order to cap off the loose wire ends. However, some DIYers also take the choc blocks and use band aid or sello (Scotch) tape on the wires. Band aid is actually pretty common. Tends to fall off after some time. Lovely!
Posted By: SvenNYC Re: Bathroom Electric - 11/03/04 08:24 PM
Ragnar said:
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but you may only use one set of screws (or strip the wires long enough to get them under both screws from one side).


Wait, I thought the whole point with these terminal strips was so that you could join two wires together by inserting one wire through one end and the other through the other end and clamping down with the screws, making sure the wires don't poke out of the sides in order to avoid danger of electric shock.

At least that's the way I've used (and seen them used) as terminal blocks. You have the appliance's internal wiring entering through one row of holes and fastened down with one row of screws. The external wire enters the opposite row and is clamped by the oppsite screws. Wires have to be trimmed so that nothing is exposed.
Posted By: SvenNYC Re: Bathroom Electric - 11/03/04 08:26 PM
John Steinke wrote:
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The typical wiring method in Israel is to use a rotohammer to chisel irregulat trenches in the block wall, insert 'smurf' tube and boxes, then plaster over.

Same method is used in Colombia when dealing with masonry wall. Trench is cut in the solid masonry wall, conduit and box is laid and buried. Wire (THHN) is later fished through.

A labor-intensive method, but it beats dealing with drywall and lath & plaster (I hate that type of flimsy stuff). I'm sure that method is also used in the USA, no?
Posted By: John Steinke Re: Bathroom Electric - 11/04/04 12:29 AM
No, Sven, we generally do not carve trenches into masonry. Either the wiring is placed in a space between layers of brick, and enter the back of the box, or the conduit is built into the conduit is placed as the wall is built.
For existing installations, the practice is to run metal conduit on the surface.
Our code does, technically, allow your "carve, bury, and cover" method, but I've never seen it used (except for very short runs).
Posted By: Texas_Ranger Re: Bathroom Electric - 11/14/04 09:56 AM
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Wait, I thought the whole point with these terminal strips was so that you could join two wires together by inserting one wire through one end and the other through the other end and clamping down with the screws, making sure the wires don't poke out of the sides in order to avoid danger of electric shock.

That's what those choc blocks are really intended for, hooking up light fixtures or appliances. however, they're _not_ rated for the full 10 or 16A of house wiring, unless you put all wires under the same screw. I think they'Re only rated 6A side-to-side.

On a web site of a restoration project I saw the carve-and-conduit style usd in the US, however, go to www.pleasantplainsfarm.com
Long ago joe Tedesco also posted a pic of a piece of BX buried in plaster, acceptable new wiring.
Solid brick walls sure beat drywall or plaster&lathe anytime!
Need the right tools to work on it though. Drywall saw and fish tape won't get you too far, you'll need cold chisel, sledgehammer and maybe a Hilti. Every sparky here has at least basic knowledge of plastering, otherwise they'll be out of the job pretty soon... if you do any retrofit work there won't be a plasterer on the job who fixes the walls after you're done.
Posted By: pauluk Re: Bathroom Electric - 11/14/04 07:59 PM
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@Paul: for the real old bakelite ones you'd need a hack saw! And the even older ones were made of porcelaine
Porcelain versions are still available for use in high-temperature areas such as the internal connections in heaters:

[Linked Image from tlc-direct.co.uk]

Regarding the method of connection of the strip connectors, I've used all three methods. For connections between cables within fixture boxes (splicing neutrals at a switch, for example) I strip the conductors to be long enough to be clamped by both screws and feed the wires in both sides or one side only, whichever is convenient for the particular application.

Use of one screw per conductor is typically found within an appliance, such as where a flexible supply cord is connected to the heat-proof internal wiring.

I've never heard of these connectors not being rated for the full current when used in this way.



[This message has been edited by pauluk (edited 11-14-2004).]
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