Cable protection system

In the history of electrical engineering with regard to mining equipment, attempts have been made to put such systems into practice [6, 27]. In the following, a cable protection system will be described in more detail. This system successfully demonstrates for the first time how to avoid the ignition of gas-air atmospheres in case of cable faults [57],... 

This fact enables UR 1/400 to act as a cable protection system in gassy coal mines endangered by firedamp, i.e. methane (dT4). 

In the final part of the book, focal points are financial considerations (Chapter 9), inspection, maintenance and repair of explosion protected apparatus (Chapter 10), apparatus for installation in zone 0 and in zone 2 (Chapter 11) and cable protection systems, especially for underground installations in coal mines (Chapter 12). 

The next step is to apply a number of loss control credit factors such as process control (emergency power, cooling, explosion control, emergency shutdown, computer control, inert gas, operating procedures, reactive chemical reviews), material isolation (remote control valves, blowdown, drainage, interlocks) and fire protection (leak detection, buried tanks, fire water supply, sprinkler systems, water curtains, foam, cable protection). The credit factors are combined and appHed to the fire and explosion index value to result in a net index. 

Figure 11 -7 shows the basic circuit diagram for a tank with two domes. The protection current flows via the two interconnected openers of the cover grounding switch to the cathode connection. If one of the covers is opened, the protection current circuit is broken and the tank grounded via the closing contact. The unconnected cable connection of the tank is without current and can be used for measuring potential. By this method, only one tank at a time is separated from the protection system while the other parts of the installations are still supplied with protection current. 

Cathodic protection has many applications, e.g. in refineries, power stations, gas, water, and oil utilities on marine structures, e.g. jetties, piers, locks, offshore platforms, pipelines, ships hulls, etc. and on land structures, e.g. buried pipeline, storage tanks, cables, etc. For each use, the cathodic protection system requires careful design, either impressed current, sacrificial anodes, or a combination of both may be chosen. There may also be other protection systems, e.g. paint, the nature of which will affect the design parameters and must be taken into consideration. 

Type of protection EEx e II T Cable connector system for heating units Type of... 

In classic intrinsically safe instrumentation multicore cables lead from the control room into the explosion protected system. Several sensors/actuators are wired to a terminal box and connected to the multicore cable. 

When high voltage motors are being considered, it is usually found that the minimum conductor size of the cable is determined by the let-through fault withstand capability rather than the full-load or starting current. Cable manufacturers provide graphical data for fault withstand capabilities of their cables, which are based on practical tests. These aspects are also associated with the protection system used for the motor, e.g. a contactor-fuse combination, a circuit breaker, the protective relay characteristics (thermal, inverse time with or without instantaneous or earth fault elements). 

Filtration is provided by a C2A1 canister attached to the mask by a corrugated hose the canister is housed in a specially designed canister carrier. The M42 integrates with the combat vehicle filtration protection system. The M42 also has a dynamic microphone that integrates with the combat vehicle via a microphone cable.19,20... 

Wide Area Networks (WANs) - No amount of redundancy within the data centre will protect the service if someone conducting highway maintenance nearby puts a spade through the network cable. Resilient systems often have multiple outward-facing network connections travelling in different geographical directions. 

The cable support system (for example, cable trays, conduit), may be common for both deenergize to trip and energize to trip systems, unless separation is required for other reasons (for example, electromagnetic interference). On energize to trip systems, consideration may be given to adding fire protection to the cable trays in fire risk areas. 

This section concerns the dismantling of all the heat evacuation circuits and other materials contained in the rooms housing the circuits (electric cables, ventilation systems, fire protection systems, lighting, etc.). The significant aspects of SG building installations dismantling operations are ... 

Steel erectors, just as in the general fall protection standard, can choose the best fall protection system for the job. The standard says protection from fall hazards can be a perimeter safety cable, guardrail, safety net, personal fall arrest, or a fall restraint (positioning device) system. 

The choice of materials used in a radiation environment should take into consideration the effect of radiation on material properties. For example, optical fibres may be damaged when exposed to neutron fields. This would have an adverse effect on the safety function of all systems served by such cables (usually computer based control and protection systems). 

The computer system of the station control and data acquisition is a distributed micro processer based systems. A digital multiplexed control system takes the place of hard wired analogue control. This accounts for a significant reduction in cable usage. Built-in diagnostics and board level maintenance makes restoration of operability of any fault in the system a matter of replacement of printed circuit cards. Automatic control systems and procedures are deployed to simplify these procedures and power level manoeuvers. In case of unsafe conditions the reactor protection system (PMS) takes over and automatically scrams the reactor and actuates the relevant safety systems. Diverse methods are used to assure the shutdown of the reactor in hypothetical situations. The systems also provide for post-accident monitoring. 

This study is concerned with the application of heat-shrinkable plastics tubing and mouldings as terminations for medium-and high-voltage power cables in replacement of traditional cable termination systems. The first installations were at low voltages (240-440 V) in weather-protected... 

Raychem commenced their development of power-cable termination systems about 1961. The first applications were in MV, weather-protected situations, and were soon extended to outdoor MV applications. 

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