The Golden State: Where & How to Live, Secure, Visit, Enjoy and Thrive in California
Care And Repair Of The House
In case of fire or other emergency, or when a house is to be left unoccupied for long periods, the main switch should be opened, thereby cutting off the building from the source of electrical supply.
If it is not desirable to cut off the current from all of the circuits at the same time, the current in any one circuit may be cut off by removing the fuse plugs controlling it. Before removing a fuse it is advisable to open the main switch, as it is dangerous to handle fuses on line circuits. In modern installations there is one fuse for each branch circuit, but in older work there may be two. Branch circuit fuses may be in the cabinet with the switch, or this cabinet may contain main fuses only, the fuses for branch circuits being in a separate cabinet. In order to facilitate future repair work the fuse holder should be labeled and a chart should be made showing the rooms and outlets which the fuses control-. To determine which circuits are controlled by the various fuses, let one person try the lights throughout the house while another removes and replaces fuses. Every light which "goes out" when a certain fuse is removed is on the circuit controlled by that fuse.
Be sure that a line is "dead " before doing any work on it. The careful electrician would make sure of it by pulling the main switch and removing the fuse plug controlling that particular circuit.
4. REPLACING A FUSE PLUG
The wires in each house circuit are intended to carry a certain load of current and if overloaded may become heated and cause a fire. To guard against this danger, the current passes through a safety device known as a fuse. This consists of a small screw plug fitted with a short length of metal having a low melting point. When more than the specified load is placed on the wire this metal strip promptly melts, breaking the circuit. This is commonly called '" blowing out a fuse." It is sometimes difficult to determine which fuse has Mown, but usually the mica "window" covering the front of the plug is badly smoked, and upon closer examination, it will be seen that the small metal piece inside the plug has burned out. A blown-out fuse may be more easily located if a chart is made, showing the outlets controlled by each fuse. The chart is especially useful in case a fuse blows out at the inner base of the plug, without discoloring its "window."
The capacity of the fuse is usually marked on the metal rim around the face or on the metal contact end. This may be 6, 10, 15, and up to 30 amperes, depending on the normal loading capacity of the circuit. The larger-rated fuses are generally used on the main service wires and where electric ranges or electric water heaters are installed.
