Cable increased safety

U = this mark indicates that the certificate is a component certificate for electrical equipment which cannot operate on its own (e.g. cable entries for enclosures in increased safety - e -). 

A second example of encapsulation is a contactless operating plug-and-socket system with integrated electronics suitable for zone 1 application (Figs 6.37 and 6.38). The system allows power and data transmission with PROFIBUS DP/VI. The socket with an integrated pigtail cable is attached to a terminal box in increased safety - e Within the socket, the 24 V DC power... 

In a very general sense, terminal boxes, regardless of their type of protection (increased safety or flameproof), ensure an additional cooling surface and a greater distance between the thermic critical cable entries and the source of heat losses, compared with direct cable entries into the flameproof main compartment of the apparatus. 

In this example, the flameproof enclosure is fitted with a terminal compartment in increased safety - e As an alternative, flameproof cable entries or conduits may be fitted. 

Other investigators [135-140] have studied the initiation of secondary explosives by laser radiation. With direct initiation of secondary explosives, for example, by incorporating a fiber optic cable interfacing the main charge, primary explosives become unnecessary, thus providing increased safety and reliability in explosive trains. 

Another example of such advancement is the use of fiber-optic cables that have been incorporated through the entire length of pipes, thereby enabling the operator to measure temperatures and stresses at thousands of points along the pipe in a very short time. Such systems are used to detect pipeline leakages, verify pipeline operational parameters, prevent failures of pipelines constracted in landslide zones, optimize oil production from wells and detect hot-spots in high power cables. In essence, this advancement increases safety, decreases economic losses and optimizes maintenance cost. 

The design is supported by stress, fatigue, buckling and safety analysis, and relies on standard steel. Only in localized areas would higher quality (albeit still standard) steel be needed. Carbon hber instead of steel pre-tensioning cables may provide higher performance at a marginal cost increase, but are not strictly required. 

Silicone rubbers bum if the temperature of the flames exceeds 600-700 °C. However, their combustion does not release toxic products, and there is an isolating layer of carbon dioxide on the product. If this rubber is sealed in a glass or asbestos shell, the cable can endure operating voltage and ensure normal functioning of the electric circuit even in a fire. These properties help to reduce the requirement for wires and cables in most cases by 20% and noticeably increase the safety of operation in case of overloads and fires. 

WEEE has had a direct affect on flame-retardant use, because flame retardants are used in almost all electrical and electronic equipment to prevent fires from short circuits. This directive lays down rules for disposal and recycling of all electrical and electronic equipment that goes back to the previous incinerator discussion. For flame retardants, this directive affects how the plastic parts, cable jackets, and enclosures are flame retarded. If the plastic cannot be reground and recycled, it must go to the incinerator, in which case it cannot form toxic by-products during incineration. This has led to the rapid deselection of brominated FR additives in European plastics that are used in electronics, or the complete removal of FR additives from plastics used in electronics in Europe. This led, in turn, to increases in electrical fires in Europe, and now customers and fire-safety experts demand low environmental impact and fire safety. However, the existing nonhalogen flame-retardant solutions brought in to replace bromine have their own balance-of-property issues, and so research continues to develop materials that can meet WEEE objectives. 

Based upon these considerations, Fig. 6.195 will demonstrate that faults in cables, e.g. a conductive path between two different intrinsically safe circuits, may initiate increased voltage or current values exceeding the limitations of intrinsic safety. 

Even more difficult task is to protect the polymeric structural materials in nuclear installations, such as electrical cables or decontaminable flooring in a nuclear power station or industrial gamma irradiator. The required dose-tolerance here can be as high as 1 MGy and a risk-increasing factor is here the low dose rate, sensitizing even the cross-linked polymers against radiation degradation. The warranted life time span here is typically 30 years, and safety aspects are extremely important. 

Water quality is an issue of international concern due to increasing contamination from a variety of sources. The most common types of water examined are surface waters, ground waters and waste waters. Common indicators of the quality of water are conductivity, pH, ion and nutrient measurements. The HI-991300 from Sheen Instruments Ltd (Figure 8.9) is a portable conductivity meter that measures conductivity as well as total dissolved solids (TDS), temperature and pH. For conductivity, it has a range from 0-3999 pS/cm with a resolution of 1 pS/cm. All readings are compensated automatically for any temperature variation. Calibration is carried out manually with provided solutions. The device can be operated with one hand and the rubber keypad is splash-proof. The HI-991300 is supplied complete with a conductivity probe with a one meter screened cable, a wrist strap for safety and the 9 V battery. 

Yellow/green wire in an electrical power cable connected to the ground (earth) of the building where electromedical equipment is used. It serves two purposes one increases electrical safety and the other reduces noise. It is not supposed to be current-carrying in a fault-free system. Often (wrongly) used synonymous with the reference wire of the preamplifier. Antonym not grounded = floating. 

For increased traction, POWERBACK Rubber Duct Cable Protectors are now available with optional Velcro strips for use on carpet. These non-metallic, flexible rubber protectors are extremely durable, easy to install, and organize portable cords and cables while reducing trip hazards. Fits multiple cable sizes. Available in 5- or 10-ft.lengths and can be sUt on the bottom for easy cord insertion. Checkers Industrial Safety Products, www.cableprotector.com, (800) 438-9336. Circle 247... 

Figure 5. Risk increase and risk decrease for contact with electricity-high voltage cables for various safety barriers.

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