Basic Electrical Installation Work

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When the cell connected load, the chemical energy converted electrical energy. They have long shelf life and leakproof construction, and are used watches and hearing aids. After testing, the emergency system must carefully restored its normal operative state. Definition A secondary cell has the advantage of being rechargeable. Figure 14.5V. Once the active chemicals are exhausted, the cell must discarded. Self-contained units are suitable for small installations about 12 units. Primary cells A primary cell cannot recharged. Larger voltages are achieved connecting cells series. Definition A primary cell cannot recharged. .61 The construction lead-acid battery.35V, and can have very large capacity small physical size. Secondary cells A secondary cell has the advantage being rechargeable. A record should kept each item equipment and the date each test qualified responsible person. A lead-acid cell secondary cell.61 shows the construction lead-acid battery. 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.Basic Electrical Installation Work 342 The British Standard recommends that the full load should carried by the emergency supply for least every months. Mercury primary cells have emf 1. Negative connecting bar Positive connecting bar All plates deeply ribbed Negative plate Separator Positive plate FIGURE 14. may necessary produce the record evidence satisfactory compliance with statutory legislation to duly authorized person. the cell is connected suitable electrical supply, electrical energy stored the plates the cell chemical energy. Thus, supply can be provided connecting four cells series. 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. the cell con- nected suitable electrical sup- ply, electrical energy stored the plates the cell chemical energy