Cables rating

Onshore 2 inches of Concrete UL 1709, 2 hour rating Offshore Ablative or intumensent materials, UL 1709, 2 hour rating Cable Trays Stainless steel cabinets or fire rated mats, UL 1709, 20 minute rating ESD Control Panels. Stainless steel cabinets or fire rated mats, UL 1709, 20 min. rating EIVs. (If directly exposed) -Stainless steel cabinets or fire rated mats UL 1709, 60 min. EIV actuators Stainless steel cabinets or fire rated mats UL 1709, 20 minute rating Firewalls ... 

PVDF—Abbreviation used to denote polyvinyl difluoride. A type of material used for cable jacketing. Often used in plenum-rated cables. Preform—A glass structure from which an optical fiber waveguide may be drawn. 

Curve 1 PD intensity, intact insulation Curve 2 PD intensity, damaged area 1 cm2 Curve 3 PD intensity, damaged area 6 cm2 Curve 4 tan 8 for cases 1-3 U0 = rated cable voltage between conductor and earth or between conductor and screening. 

UQ = rated cable voltage between phase conductor and conductor screening U = rated cable voltage between phase conductors... 

The effect of the decomposition products could be reason for the increase in tree growth rate in dicup cured coated wires after vacuum drying. In two separate sets of experiments the vacuum dried wire compared favorably with PE but less than favorably with XLPE more extensive vacuum drying appears to have a more deleterious effect. The decrease in the AC breakdown strength after vacuum drying on slabs machined from the insulation of a 138 kV rated cable has previously been reported (16). 

One issue when rating cables is what to take as the scaling denominator Test rigs with equal areas or equal numbers of cables have been used when comparing the behaviour of different products. All data generated should be freely available for fire safety engineers to use when assessing the potential consequenees of fire in a cable bundle. 

To plan a splice point at the building entrance to transition from nonrated outdoor to indoor rated cable designs. The added loss of the splice is small and usually not significant in the link loss budget... 

Onshore 2in. of concrete UL 1709, 2h rating Offshore Ablative or intumescent materials UL 1709, 2h rating Cable Trays Stainless steel cabinets or fire rated mats UL 1709,20min rating... 

Palatinol 79TH-I is inhibited. The retention of physical properties of the compounds pass Underwriters Laboratories requirements for 105C rated cable. 

For the 1-1-1 case, two full rated cables have been included, assuming that the alternator has two independent stator windings. This configuration is required to maintain single fault tolerance in the PCAD subsystem. 

For primary insulation or cable jackets, high production rates are achieved by extmding a tube of resin with a larger internal diameter than the base wke and a thicker wall than the final insulation. The tube is then drawn down to the desked size. An operating temperature of 315—400°C is preferred, depending on holdup time. The surface roughness caused by melt fracture determines the upper limit of production rates under specific extmsion conditions (76). Corrosion-resistant metals should be used for all parts of the extmsion equipment that come in contact with the molten polymer (77). 

Electric Submersible Oil Well Pump Cable. These cables are rated up to 5 kV and are designed for highly corrosive oil wells that besides oil also contain brine and other harsh chemicals as well as gases under high pressure and high temperatures (6). Insulations can be based on polypropylene for low temperature wells or on ethylene—propylene mbber which is compounded with special ingredients in order to resist the environments of high temperature wells (Fig. 4). 

The cables designed for use at voltages over 49 kV require that the conductor and insulation shields be firmly bonded to the insulation in order to avoid any possibiUty of generating corona at interfaces strippable insulation shields are not accepted. The A ETC specifications for cables rated for 59—138 kV require a volume resistivity of one order of magnitude lower than for the medium voltage cables. 

R. B. Blodgett, "Ethylene—Propylene Rubber and Crosslinked Polyethylene as Insulations for 90°C Rated Medium Voltage Cables," Rubber Chem. Technol, 52, 410-424 (1978). 

Since the starting inrush current is kept moderate for all types of drives, it can economize not only on ratings of the switchgears and cables but also on the size of the generator when a captive power is required to feed the load. 

In some cases, where the nearest rating of the fuse itself is too high for the rated current, a larger cable is recommended. The thermal (/ - t) characteristics of all such components will vary from one manufacturer to another and may not be readily available with a design or a field engineer, while making the selection. The manufacturers of such components therefore as standard practice, perform this coordination for their products and make such data readily available for the user lo make a quick selection. It may be noted that OCR and fuses at least, of different brands, will require a new coordination. 

To the basic current requirement is applied the derating faetors for various service conditions, as noted in Section 1.5.4.2. The equipment, devices and components may then be cbosen to be as close (nearest higher) to this rating as possible from the available standard ratings. Based on these ratings, the minimum cross-sectional areas of the other current-carrying parts used in the circuit, such as interconnecting links and the cables-are calculated. 

Table 13.15 Current rating and technical data for 1100 V, single-core flexible, PVC insulated copper conductor cables for control and power wiring...

The ratings and sizes of main components and cables can be selected from manufacturers catalogues. But cables required for the switchgear internal control and power wirings, being typical of all, are normally identified by their cross-sectional area rather than the current ratings. We have therefore piovided the technical data and current ratings for the most common sizes of such cables for a ready reference in Table 13.15. 

Figure 13.48(b) A typical installation of a low-rating switchgear assembly on a cable trench... 

A 16.6 Skin and proximity effects in a multicore cable 16/547 A 16.7 Short-time rating of cables 16/547 A 16.8 Termination of cables 16/548... 

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