fused connection units

[ban-all-sheds]

..Grid plates etc are new to me, so am off to read up.
P

MK Grid Plus here

MEM Spectra here

Crabtree Rockergrid here

I'm sure that all of the major brands have equivalent ranges.

 

[securespark]

Sorry to latch on so late

FWL

Your reasons re FCU's make no mention of regs, just "common sense" and "personal preference"

And why mention that you've been using the net since 1991 and bulletin boards for 7 years? What is your point?????

thought the net was created in 92, but there u r.

 

[pipme]

Hi,

Thanks for the addresses Baz.

Some interesting stuff, as well as the component adverts.

P.

 

[ban-all-sheds]

Rather nice solution there Ban, Never seen it done but it is certainly workable, my only thought on this would be whether this would fall outside of what the NICEIC or IEE find acceptable.

Perhaps Il78, as an NIC Tester will be able to shed light on this for us.

I do like it in theory, and can certainly see no problem with it.

It's what I plan to do soonish, as I want to install a bathroom fan switched and powered by the shower circuit. There's probably some rule about not doing it, but I can live with that. I do have to make it as safe as possible, though, and since I'm not going to wire up the fan with 10mm, somewhere I've got to come down from that to 1 or 1.5mm, so I will need to fuse both the permanent and the switched live.

 

[Big_Spark]

Ban, I have spoken to the IEE and the NICEIC on this point, and as long as the Earth is common to both spurs, and they are in Dual accessory boxes and clearly labelled, niether have a problem with this solution.

Nice to know sparks can find a solution to a problem which doesn't cause the IEE or the NIC to their respective knickers in a twist!

 

[ban-all-sheds]

...
thought the net was created in 92, but there u r.

Ah the old "The Internet and the World Wide Web are one and the same thing" confusion.


The basic idea of the Internet was first proposed in 1962 by a researcher at MIT.

The first wide area network (using the telephone network) happened in 1965.

The proposal for a research network called ARPANET (the network which grew into the Internet) was made in 1967.

The specifications for the communications hardware needed were issued in 1968.

The company that won the contract to develop the hardware, Bolt Berank & Newman (BBN) installed the first examples at UCLA, the Stanford Research Institute, UC Santa Barbera and the University of Utah in 1969. Even though there were only 4 computers linked by the end of 1969, they were already using the idea of tables to hold host name to network address mapping information.

ARPANET continued to expand over the next few years, more network protocols were developed, and in 1972 email was invented.

1972 also saw the emergence of the idea of an open-architecture called the "Internetworking Architecture" that could be used to interconnect different computer networks, irrespective of the type of each individual network. At the same time Bob Kahn, who helped design the first network hardware at BBN, and had now left and joined DARPA was working on a research programme for packet switched radio called "Internetting", a key requirement for which was a reliable end-to-end protocol that could maintain effective communication in the face of jamming and other radio interference, or withstand intermittent blackouts such as caused by being in a tunnel. The network protocol which had been developed for ARPANET was not adequate for this, and so Kahn outlined the requirements for something different, and in 1973 he asked Vint Cerf at Stanford, who had done a lot of the original work on the ARPANET network protocols to work with him on the detailed design, and together they produced the specifications for what became the Transmission Control Protocol/Internet Protocol (TCP/IP).

DARPA let three contracts to Stanford, BBN and UCL to implement TCP/IP (it was simply called TCP in the Cerf/Kahn paper but contained both components). The Stanford team, led by Cerf, produced the detailed specification and within about a year there were three independent implementations of TCP that could interoperate.

TCP/IP was adopted as a defence standard in 1980. This enabled defence to begin sharing in the DARPA Internet technology base and led directly to the eventual partitioning of the military and non- military communities. In 1983, when it switched to using TCP/IP, ARPANET was being used by a significant number of defence R&D and operational organizations. The transition to TCP/IP permitted it to be split into a MILNET supporting operational requirements and an ARPANET supporting research needs.

Thus, by 1985, the Internet was already well established as a technology supporting a broad community of researchers and developers, and was beginning to be used by other communities for daily computer communications. Electronic mail was being used broadly across several communities, often with different systems, but interconnection between different mail systems was demonstrating the utility of broad based electronic communications between people.

During this time, many other key technologies were being developed elsewhere. Xerox were working on Ethernet at the Palo Alto Research Centre (PARC), Intel had invented the microprocessor, and different companies were starting to make small "personal" computers, although the first product to use the term as a trademarked product name was the IBM PC in 1981, launched a year after they first had talks with a spotty computer nerd called Bill Gates about writing an operating system for it. But I digress.

A team at MIT were keen to show that TCP could be used on small computers as well as large ones, and they produced an implementation, first for the Xerox Alto (the early personal workstation developed at Xerox PARC) and then later for the IBM PC. That implementation was fully interoperable with other TCPs, but was tailored to the application suite and performance objectives of the personal computer, and showed that workstations, as well as large time-sharing systems, could be a part of the Internet.

Widespread development of LANS, PCs and workstations in the 1980s allowed the nascent Internet to flourish. Ethernet technology, developed by Bob Metcalfe at Xerox PARC in 1973, is now probably the dominant network technology in the Internet and PCs and workstations the dominant computers.

This post would become impossibly long if I went into all the other parallel developments and key decisions that took place during the 1970's and 80's - you can read a lot more here .

Over that time, people developed many tools for searching for information on the Internet, such as WAIS, Veronica, Gopher, but they were all text based. In 1990 Tim Berners-Lee, then working at CERN, wrote a graphical browser program which he called "WorldWideWeb", and the rest, as they say, is history. The concept of the WWW, and GUI browsers, utterly transformed the way that the Internet was used, but the Internet itself predates the WWW by a good decade, and still, today, is held together by the nuts and bolts designed by Bob Kahn, Vint Cerf and others a good 30 years ago.


Nothing to do with FCUs, but I hope some of you found it interesting.

 

[ban-all-sheds]

Ban, I have spoken to the IEE and the NICEIC on this point, and as long as the Earth is common to both spurs, and they are in Dual accessory boxes and clearly labelled, niether have a problem with this solution.

Nice to know sparks can find a solution to a problem which doesn't cause the IEE or the NIC to their respective knickers in a twist!

Blimey - and I'm not even a sparkie...

 

[gjh]

Aargh, its late and I'm getting confused - I think I'm missing something fundamental here.

All I want is to install a bathroom fan [with timer] and ceiling light, both operated off of one switch. I thought all I had to do was have a 3A unswitched FCU feeding the light and the fan, with a 3 pole isolator to isolate the fan if required - resulting in three things to attatch to the wall outside of my bathroom; Light switch, unswitched FCU and 3-pole isolator.

However I now read that it is 'frowned' upon to run both a light AND a fan off a single fused spur - why? is it against the regs? would it really be better to do it another way? how would I do it without having to mount loads of switches, FCU's, etc to the wall [I do not want to hide anything in the loft, for ease of future maintenance and personal preference].

The following is how I WAS going to do it:

A second question would be is there such a thing as a switched FCU but WITHOUT a flex outlet - ie one that looks EXACTLY like a standard 1G light switch.

 

[ban-all-sheds]

Ignore the frowners - what you plan to do is perfectly safe.

However there is an alternative which will smooth their furrowed brows, achieve what you want, including fusing the fan but not the light, and obviate the need for the fan isolation switch:

Lots of switched spurs are available without front flex outlets:

 

[plugwash]

not sure i have seen a DP pull switch for sale though.....

 

[ban-all-sheds]

MK 15A one:

OK - it is slightly chunkier than a 5A light switch, but not a lot.

 

[securespark]

The above MK switch is the same design as the old (60's) light switches. You can also get a neon pattress for this switch. Or, if you can't get hold of MK easily, you can use a 45A DP switch - a bit overrated, but it will do the job beautifully.

 

[gjh]

Thanks for the reply...

Can you get a DP wall switch instead of a pull switch (to mount on the wall outside of the bathroom or course.

 

[gjh]

I think I've probably asnwered my own question here:

http://www.mem250.com/products/product_detail.asp?productcode=FM2200

I assume it will not matter that the switch is rated at 20A and I will only be switching a 3A fan?

 

[plugwash]

yeah a switch with an overly high rating is not a problem