- Thanks Joe!

[This message has been edited by Webmaster (edited 03-09-2004).]

wood boxes sound kind of like a fire hazard. don't worry though, they're perfectly safe because they are lined with asbestos

Always interesting to read old stuff like this.

Wooden panelboards, with glass panels in the larger sizes, were quite common in England right up to the 1930s, although they weren't usually asbestos lined. Each plug-in porcelain fuse carrier (rewireable type) typically had a small asbestos insert.

Wooden patresses for light switches were also the norm, and in later years some people even constructed "back boxes" for the newer-style switches using any old scraps of wood.

Great stuff, Joe!

Hi Paul,

The wooden pattress, in my experience, has always been used when mounting a surface mount switch or socket, like the one shown in the picture, to a plaster or masonry wall.



The reasoning is that you would use larger and longer screws (or nails) to anchor the block to the wall and then use the tiny wood screws that normally come with the switch or socket to fasten it to the pattress.

It makes for a much more secure installation than just using small wood screws to directly anchor the switch to the plaster wall. That way the device won't pull away from the wall when used.

Hey that's really neat!
I remember my grandmother's house when I was young. The fuse panel was in a wooden enclosure with a glass front, just like the one pictured.

Sven,
Yes, that was the typical application of the pattress block in Britain as well, and seeing as the majority of old houses had masonry walls, they were used by the dozen.

By the way, what holds the cover of that switch in place? The equivalent "tumbler" switches here had either a round threaded boss in the middle so you just tightened the cover onto it, or they had two small screws above and below the toggle to secure it.

Here wooden patresses were usually plastered in flush with the wall to provide something to screw into. If done right definitely much more solid than todays plastic wallplugs.
Weird, our toggle switches always had the cover screws to the left and the right of the toggle, except for the doubles. Some German retro toggles just have _one_ screw. Looks pretty weird.

Paul & Ragnar,

The plastic cover snaps onto two metal clips on the base. You have to be careful when replacing the cover because the phenolic plastic breaks easily.

It used to be that the base was made out of glazed ceramic (porcelain). However all the surface-mount made within the past 20 years have been entirely made of thermoset plastic (Urea or Bakelite).

The older tumbler switches here had a procelain base as well. I'll see if I can dig one or two out of my junk box and post some pics later.

I just got ahold of a 1953 (7th) Edition on this book. One section details how to test for voltage using Fingers and Tongue.

I wonder how long that section stayed in the Book?

Bill

Bill:

Only the 13th Edition survived hurricane Sandy. I lost a few older ones back to mid60s

What section is that in?? Hope it's not still in there.

Funny, someone earlier in the week was talking about one of the 'older' inspectors that used to test with two fingers!!! They asked me if he was still around.

John,

It's in Division 1, Fundamentals, Measuring, Testing and Instruments.

Disclaimer - Not a Good idea!!

I didn't want to quote here, but others have.

Bill

When my wife and I bought our first house, and before I got into the trade, we had an electrician come over to move a ceiling outlet for a light fixture. He was a former school teacher and friend of my father-in-law. I watched him as he worked and offered any assistance. At some point he checked to see if the circuit was live and did exactly that - used two fingers! Never forgot that. Years later when I was apprenticing I told my journeyman this story and despite being in the trade for nearly 40 years he said he never seen anyone in the trade do that.

I have detected voltage with my fingers but never on purpose
I can say 400hz will wake you up. It is more of a ring than a buzz.

My old house which was wired in 1953 had wooden blocks behind all the switches and sockets except for the cooker control unit which was a big iron box fixed straight to the wall

Greg:

I remember having y hand thru a handhole in a pylon neon sign. Dumb move on my part was not confirming 120 volt was 'off''. Got to feel the sting of the 15Kv neon xfr.

Like I said, long ago, and DUMB.

In Austria I've seen panels partly made of wood well into the 1970s. My parents own a weekend home that received a new combo meter enclosure/consumer unit in 1976. The visible parts are all powder-coated metal but once you get behind the covers and frame it's a wooden box lined with asbestos. I suspect that might have been an ad-hoc solution on site because the wall is only barely thick enough to accommodate the unit, more commonly these enclosures were just open and you could see the plastered brick wall through them. I think completely enclosed meter cabinets only became a requirement in the mid-1990s so now there's usually a metal tub. Mind you, these things are large, most distribution network operators suggest three-meter enclosures for single-family domestic buildings, either for a night-rate meter and tariff switch or more recently for photovoltaic cells with a dedicated meter.