Incandescent Bulb in addition to the use of lighting, but also can be used to limit the current, light instructions.In addition, by the filament resistance to the positive temperature coefficient and other characteristics, but also in the electrical maintenance to play a lot of convenient and practical role, the following list:
1, find the circuit failure to single-phase circuit, for example, such as a short circuit or ground fault, the home switch will trip or burn insurance, then all the appliances should be turned off all the home in the main switch line A 220V / 100W or so light bulbs, connected to the insurance after closing the main switch, such as light bulb, to prove that the line has a short circuit or ground, and then break off the branch; when disconnecting a road after the light bulb does not shine, To prove that the branch failure. Operation can be power consumption from small to large, respectively, immediately after the closure of the electrical appliances immediately cut off, the bulb should be slightly off after the extinguished, the greater the power the higher the bulb brightness, such as electrical appliances Power is greater than 200W, you can re-parallel light bulbs at both ends of the original 100W, when there are short-circuit ground fault, the light bulb will be very bright, and sometimes the point of failure will smoke or spark, so it is easy to detect the point of failure. Cable or overhead lines of the inter-phase breakdown or ground fault, can also be used to find a similar approach.
2, find substation control circuit failure in a special control power substation, short circuit fault can also be used to find the above method, but should choose the same level of control voltage bulbs (if necessary, in series or parallel way). For the ground fault, to DC, for example,Incandescent Bulb if the cathode appears ground, put the two ends of the lamp connected to the negative side of the power supply and ground; such as the negative ground, then the bulb connected between the positive and ground, then the light bulb With the size of the grounding resistance of the fault point and issued a different brightness of light, the point of failure may also smoke or a small spark; such as the point of failure without obvious symptoms can be taken to check the short circuit, branch road section by paragraph The point of failure.
3, check the small coil insulation damage Small contactors, relays, small motors and other coil insulation breakdown, the control loop insurance will fuse, sometimes the appearance of the coil no obvious scars, with a multimeter to measure the DC resistance also no significant changes in the coil In the string into a voltage level with the light bulb, access to the power supply after the coil layer of insulation will breakdown breakdown, the light bulb will be bright, such as a sub-substation more than three-phase watt-hour meter at the same time a greater error, After checking, this watch a few 380V three-phase voltage coil share a group of insurance, but also found that C-phase insurance fuse, put on insurance and then fuse, it is estimated that the voltage coil burned off the power supply with a multimeter to measure the table C Phase coil DC resistance difference is very small,Incandescent Bulb can not determine which coil failure.With two 220V / 100W bulb in series, the string into the C-phase insurance, the light bulb after power transmission, only by the power meter C Phase voltage line is disconnected, if the disconnect on the 3rd table C phase voltage line, the light bulb turn dark, so soon found out is the No. 3 table voltage coil burned