Basic Electrical Installation Work

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When the cell connected load, the chemical energy converted electrical energy. the cell is connected suitable electrical supply, electrical energy stored the plates the cell chemical energy. may necessary produce the record evidence satisfactory compliance with statutory legislation to duly authorized person.61 The construction lead-acid battery. the cell con- nected suitable electrical sup- ply, electrical energy stored the plates the cell chemical energy. Once the active chemicals are exhausted, the cell must discarded. Primary cells, the form Leclanche cells, are used extensively por- table power sources for radios and torches and have emf 1. Definition A primary cell cannot recharged.Basic Electrical Installation Work 342 The British Standard recommends that the full load should carried by the emergency supply for least every months.5V.35V, and can have very large capacity small physical size. Each cell delivers about 2V, and when six cells are connected series 12V battery formed the type used on motor vehicles. The batteries contained within these units should replaced about every years, recommended the manufacturer. . A record should kept each item equipment and the date each test qualified responsible person. Negative connecting bar Positive connecting bar All plates deeply ribbed Negative plate Separator Positive plate FIGURE 14.61 shows the construction lead-acid battery. Primary cells A primary cell cannot recharged. They have long shelf life and leakproof construction, and are used watches and hearing aids. Once the active chemicals are exhausted, the cell must discarded. Thus, supply can be provided connecting four cells series. Definition A secondary cell has the advantage of being rechargeable. Self-contained units are suitable for small installations about 12 units. Figure 14. After testing, the emergency system must carefully restored its normal operative state. Larger voltages are achieved connecting cells series. A lead-acid cell secondary cell. Mercury primary cells have emf 1. Secondary cells A secondary cell has the advantage being rechargeable