According to Wikipedia, such shutters are required by law in several countries (e.g. Scandinavian countries, Portugal). Some other countries have varying requirements depending on where the socket is, e.g. German kindergardens have to have shuttered Schuko (whereas offices or industrial workshops don't) but this is prescribed by the mandatory accident insurance's building regulations rather than by the electrical norm for sockets.The inset sockets allow using \"child safety caps\" that are plugged into the socket to close it. They have been in use at least since the 70s in Germany, and according to Wikipedia there were even ceramic shutters before plastic plugs became available)
There are certain characteristics common to British mains plugs and sockets intended for domestic use. The brass pins appear relatively solid and large compared to others. British Standards for plugs (with the exception of BS 4573) have always specified side entry flex (entry in other types is usually parallel to the axes of the pins). Since 1934, the contacts of a socket have been specified in terms of the pins of the plug, rather than by specifying the contact dimensions. The pins of both round pin and rectangular pin plugs are arranged in a triangular fashion, the earth pin being the larger and longer pin at the apex. Earthed sockets are designed to be incompatible with two-pin plugs. Both BS 546 and BS 1363 sockets, when viewed from the front with the earth uppermost, have the line aperture at the lower right.
The BS 4573 socket is for use in rooms other than bathrooms. When installed in wet areas (e.g. bathrooms), for safety reasons it is normally found incorporated into a shaver supply unit which includes an isolation transformer and meets various mechanical and electrical characteristics specified by the BS EN 61558-2-5 safety standard to protect against shock in wet areas. Shaver supply units also typically accept a variety of 230 V two-pin plug types including BS 4573, Europlug Type C, and Australian two-pin plugs. The isolation transformer often includes a 115 V output that supplies a two-pin US Type A socket. Shaver supply units must also be current-limited; BS EN 61558-2-5 specifies a minimum rating of 20 VA and maximum of 50 VA. BS 4573 and BS EN 61558-2-5 both require sockets to be marked with the shaver symbol defined in the IEC Standard 60417-5225; the words \"shavers only\" are also often used but not required.
February 1989: BS 1363-3:1989 \"13 A plugs socket-outlets and adaptors - Part 3: Specification for adaptors\" published. This new standard covers adaptors for use with BS 1363 socket-outlets and includes conversion adaptors (those which accept plugs of a different type), multiway adaptors (those which accept more than one plug, which may or may not be of a different type) and shaver adaptors. All adaptors (except for those accepting not more than two BS 1363 plugs) require to be fused. All sockets, including those to other standards, must be shuttered.
Plug adaptors permit two or more plugs to share one socket-outlet, or allow the use of a plug of different type. There are several common types, including double- and triple-socket blocks, shaver adaptors, and multi-socket strips. Adaptors which allow the use of non-BS 1363 plugs, or more than two BS 1363 plugs, must be fused. Appliances are designed not to draw more power than their plug is rated for; the use of such adaptors, and also multi-socketed extension leads, makes it possible for several appliances to be connected through a single outlet, with the potential to cause dangerous overloads.
A conversion plug is a special type of plug suitable for the connection of non-BS 1363 type plugs (to a recognized standard) to BS 1363 sockets. An example would be Class 2 appliances from mainland Europe which are fitted with moulded europlugs. Similar converters are available for a variety of other plug types. Unlike a temporary travel adaptor, conversion plugs, when closed, resemble normal plugs, although larger and squarer. The non-BS 1363 plug is inserted into the contacts, and the hinged body of the conversion plug is closed and fixed shut to grip the plug. There must be an accessible fuse. Conversion plugs may be non-reusable (permanently closed) or reusable, in which case it must be impossible to open the conversion plug without using a tool.
Prior to the first British Standard for earthed plugs, George H. Scholes of Manchester introduced plugs with a hollow round earth pin between rectangular current-carrying pins in 1926 under the Wylex brand name. The Wylex plugs were initially made in three ratings, 5 A, 10 A and 15 A and were unpolarized (the current-carrying pins were on the same centre line as the earth pin). In 1933 an asymmetric polarized version was introduced, with line pin slightly offset from the centre line. In 1934 the dual plug system was introduced with the socket rated at 15 A and three sizes of plug, fused 2 A and 5 A plugs and a 15 A plug. The 15 A \"dual plug\" incorporated a socket with narrower apertures than a standard Wylex 15 A socket, that accepted only the narrow rectangular pins of the lower-rated plugs. The introduction of a 13 A fused plug, rated as 3 kW, enabled Scholes to propose their system as a possible solution for the new standard competing with the Dorman & Smith round pin solution, but it was not selected and the completely new BS 1363 design prevailed. Wylex sockets were used in council housing and public sector buildings and, for a short time, in private housing. They were particularly popular in the Manchester area, although they were installed throughout England, mainly in schools, university accommodation, and government laboratories. In some London schools built in the 1960s they were used as low-voltage AC sockets, typically 12 V, 5 A from a transformer serving one or more laboratories, for microscope lamps etc. Wylex plugs and sockets continued to be manufactured for several years after BS 1363 sockets became standard and were commonly used by banks and in computer rooms during the 1960s and 1970s for uninterruptible power supplies or \"clean\" filtered mains supplies.
This is coming from a custodian, someone who plugs and unplugs devices such as vacuums and buffers on daily basis, many many times. I have seen vacuum cables become a dangerous exposed mess because of lazy coworkers pulling on the cable from the other side of the room to unplug it, rather than walk up to it and pull it out using the body like you're supposed to. I now wonder if that fuse would protect against a bare exposed wire when someone touches it. Does anyone know (I'm not an electrician so I haven't the slightest). On our older buffer, people have run over the power cord with the buffer head in motion, causing both cable jackets to rip apart, and expose the bare copper of the wire inside. It was once simply covered with electrical tape before someone else cut the wire and reconnected it using a wire nut to rid the exposed parts. (Why not put on a new power cord you ask Idk honestly. But I do know they are very expensive themselves). When I first started, that wire was still exposed and I touched it unknowingly while using the buffer. It gave me a good kick and tripped the circuit breaker the machine was plugged into.
As with UK plugs, type D plugs are also used in other countries with strong relations with India, such as Nepal and Sri Lanka. Namibia also uses this plug model, with it being the only African country to use it as its main model.
Generally, a four-cylinder engine offers better fuel economy than a six-cylinder. Its better fuel economy is mostly due to having less horsepower but also by being smaller and reducing the weight of your car. Add in turbocharging, and there's even more improvement in fuel efficiency and performance. If fuel efficiency is a priority and you want to make fewer stops at your local gas station, then looking for a car with a four-cylinder engine is a good strategy.
However, you should keep in mind that some firearms produce a pressure wave strong enough cause hearing loss by damaging the bones behind the ear, even if the ear canal is protected by an ear plug. This is particularly true for people shooting indoors or those exposed to repeated shots from shotguns or rifles (such as waterfowl hunters or hunting guides). While ear plugs are certainly better than nothing, ear muffs are actually the most effective shooting and hunting ear protection you can wear. 59ce067264