Answer all questions 17.61 through 17.63

17.61 Design Case Study. In an actual case history of an electrocution fatality, Figure 17.18(a) illustrates the way the chuck key for a hand-held electric drill was conveniently attached to the power cord so that it would always be readily available for operator use in changing bits. The fatality occurred when the twisted wire wore through the cord insulation after continued use. Figure 17.18(b) illustrates a much safer way to connect the chuck key. What other factors probably contributed to this fatality and how could it have been prevented? Suppose that the ground pin had been broken off the plug for this drill. How would this code violation have affected this fatality? (a) FIGURE 17.18 Cause of electrocution fatality: chuck key secured to cord by twisted wire tie. (a) Unsafe, improvised attachment of chuck key. Wire or tape will eventually damage cord insulation. (b) Safer method of attaching chuck key. 17.62 Design Case Study. An architectural design and engineering firm seeks advice regarding federal safety standards for wiring for a new process being set up to manufacture dyestuff. The process uses chlorobenzene and releases ignitable concentrations in the vicinity of the process equipment. Specify the appropriate Class, Division, and Group classification for wiring and electrical equipment located in this area. 17.63 Design Case Study. In the case study of Exercise 17.62 , suppose an alternate supplier of process equipment proposes a completely closed system in which releases would only occur during repair or in event of a leak. Such occurrences arise frequently out of a need to regularly clean the infeed mechanism. Would the closed system have an impact on safety and on the prescribed wiring