ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades Flushboxes?

What type of flushbox do you guys use in your country?.
Are they made of metal or plastic?
Also, does anyone use the nail-on mounting brackets that are slowly creeping in, as an alternative to the flushbox?.

hi trumpy :

can you clear it more for us about flushbox are you describing like outlet box ?? if so yes in usa we use both and the size really varies alot depend on the devices and etc

merci marc

Gidday Marc!,
Yes, sorry I mean't Outlet Box, just wasn't sure of the term used in the US!.

[This message has been edited by Trumpy (edited 05-10-2003).]

Round or octagon (gangable) boxes. 2- or more gang are oval (more or less). They usually have 4 holes for mounting screws spaced 90 degrees. With old style round boxes (single gang only) these holes are not an integral part of the box, but there's a tiny plastic ring where the screws go into. if this is used on a receptacle the ring will eventually break out of the box. If you want to do a real solid job you tighten the clamps on the receptacle _and_ use 2 screws. Old boxes were round metal lined with tar paper, not grounded.

The most common type of boxes in my area are the square 70X70, 35mm deep (1 gang) & 129X70, 35mm deep (2 gang) galvanized steel flush box. Shallower boxes 16mm deep (for switches), 25mm deep (for sockets) & 47mm deep (cooker switches & shaver skts) are also available.
The above boxes are used for masonary walls & where dwangs (noggins) are fitted in stud partitions.
Plastic dry lining boxes - known as fastfix boxes- are used in plasterboard walls where there is no dwang. These boxes have lugs which grip the wallboard and are very common in new construction here, as most walls are of timber frame contruction, lined with plasterboard.
I will try to get a pic posted.

Aussie style stud brackets are not available here. In any case their use would be prohibited in the UK due to the fact that accessories are not enclosed when fitted in them.
When I worked in Oz I was surprised by the methods used to mount accessories. Standard practice appeared to be: Drill a hole & fit your switch or socket without any suitable enclosure / insulation for the device. Stud brackets seemed to work on the same principle, no enclosue at the rear of the device!
What happens when someone fishes inside the wall cavity with a metal object or a hand, when you only have a stud bracket mounting your accessory?
Please tell me that is not standard practice in a safety conscious country like NZ!

David,
that Australian method only sounds safe if you have devices where no live metal parts (like screws) are exposed and the cable feeding it is securely fastened. Preferably some strain relief at the device.

It must make retrofitting easy.

We use always plastic boxes. The most common are square boxes 60x60mm and 50 deep. We also have round ones for in hollow walls.

David,
I hate to say it, but these things are starting to turn up in houses around where I work.
I don't use them myself, I prefer to use the ordinary old flushbox which is screwed to a stud or dwang, I never nail them on, as it makes it too hard for the next guy to get the box out later on, if need be.
Another thing that is starting to be used over here and I'm told they're used in Australia too, is the Gib clip, this clips onto the plasterboard and is held against the wall when the switchplate screws are done up.
You can see a picture of one here www.hpm.com.au/Products/ProductFrame.asp?Page=ProductList&User=58&Group=169

[This message has been edited by Trumpy (edited 05-11-2003).]

Trumpy and David:

I presume the stud bracket is similar to NEMA-land's "low voltage ring" which is allowed to be used for speaker wire, telephone wire or TV antenna wire where you don't need a box? They are NOT allowed for 110-volt devices (switches or sockets).

It is essentially a rectangular or square ring, with a flange and tabs you flip up with a screwdriver in the case of plastic ones or in the case of the tin ones you bend back with your hand so they go behind the lath or plasterboard.

This way the ring is gripped from the back by the tabs and from the front with the flange. There are holes on the flange to screw a wall plate (where the phone box, TV antenna terminal or speaker plugs are mounted)

The wire gets fished through the wall and connected to the back of the wall plate with device.

I wonder if this is just a cheap-n-nasty way of doing things. I can't see how an open bracket could be allowed for a 220 volt (or even 110 volt) standard device. There's no protection if the device overheats or catches fire, etc.

Doesn't the box help protect the device and contain the potential fire that could happen in a faulty socket or switch?

Ragnar, how do you gang a round box or do you mean the Octagon ones? That is interesting. All NEMA gangable boxes I have seen are rectangular.

The galvanized steel boxes as David described are the most common here. All but the shallowest size have conduit knock-outs. When used in domestic systems with PVC-sheathed cables, we fit a PVC or rubber grommet into a knock-out hole to protect the cables. Unfortunately, there is no provision for clamping the cable sheath as is done with the Romex clamps on American boxes.

The plastic "plasterboard" boxes are, in my opinion, horrible and I try to avoid them whenever possible. If the cut-out in the board isn't exactly to size, or the edges have gotten chewed up a little over time, it's almost impossible to get the box to clamp up tight again.


I've never heard this term before! Is it a Scottish word?