Basic Electrical Installation Work

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