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Why is the warning lamp dangerous and why is it prohibited by the rules

 

While the light is on, and all home electrical appliances are working, everything is fine, but as soon as the machine is knocked out, you have to find and fix the malfunction. Well, if the owner of the home is an experienced electrician, then he probably has a phase indicator in the form of a screwdriver in the middle of his home tool, or certainly multimeter.

Why is the warning lamp dangerous and why is it prohibited by the rules

But what if there is neither one nor the other in the household? Is there any other way to safely detect a malfunction in an electrical circuit?

As a rule, in such cases, some home craftsmen resort to the help of the so-called control lamp or "control", which, incidentally, is very unsafe and generally prohibited by safety regulations. For this reason, a phase indicator is still better to have on the farm.


But why is the warning lamp prohibited? Let's try to understand this in detail.

Incandescent lamps, which are usually used as the notorious warning lamp, have a bad habit of failing at the most unexpected moment and in the most nasty way.

The bulb spiral can burn out at the moment of switching on from exceeding the nominal voltage (220 V instead of 36 V or 380 V instead of 220 V), the spiral may burn out and not at the moment of switching on - from a power surge, the lamp can easily slip out of your hands and break, this moment may happen short circuitfinally, a person may be shocked in the event of an awkward movement or, again, due to a sudden explosion of the bulb for one of the above reasons.

And just because of frequent reconnections, the incandescent lamp is likely to quickly fail. In short, a warning lamp is not a reliable tool.

Incandescent bulb

In table lamps or in other lighting fixtures, the bulb is always fixed securely in the holder, which, in turn, is mounted firmly in the ceiling. Such a lamp is installed strictly in its place based on its purpose.

Even if such a lighting device was turned on for business, the filament warms up, after which the lamp shines for a long time. No one flips a switch or shakes a lamp, creates extreme conditions for a lighting fixture.

Homemade voltage indicator from an incandescent lamp

But what do we get if we adapt an incandescent lamp, albeit with a cartridge, even with probes and with well insulated connections, as a control portable lamp, as a portable device? We actually get a lot of risks:

  • At first, the cold spiral of the lamp has a resistance 10 times less than in working condition, therefore, with constant on / off (while looking for a malfunction in the circuit), transients from the filament will quickly destroy it, in the end the lamp will suddenly explode and expose a person to danger of electric shock.

  • Secondly, the person himself may be mistaken. Suppose he accidentally takes a lamp at a nominal voltage of 36 volts, and installs it in his lamp holder. The lamp will definitely explode when connected to a network with a voltage of 220 volts. Danger again.

  • Thirdly, the glass of the lamp breaks easily with awkward movement. Let's say a person slipped, fell, or simply dropped a portable warning lamp from his hands. The lamp crashed, the fragments cut the man, and the malfunction with broken corks remained. As a result, the problems only increased.

  • Fourth, a person may inadvertently touch the live parts of a warning lamp with his hands or other parts of the body. If the probes of the control lamp are not sufficiently isolated, the risk of electric shock increases. The resistance of the filament of the lamp is such that even if part of the body enters the circuit in series, the impact will still be very dangerous.

Indicator screwdriver

Whether it’s at least indicator screwdriver. A current-limiting resistor and a neon bulb make the current through the body of a person holding such an indicator in their hands scanty, literally limited to a few microamps. In the normal mode of operation of the phase indicator, the weakest safe current closes through the human body to the ground.

This is completely safe, there is no longer any risk of getting under the mains voltage, and even to break such a device - you need to try very hard. Forget about the test lamp - use the phase indicator, it is designed specifically for the diagnosis of live circuits.

See also at i.electricianexp.com:

  • Incandescent lamp soft start device
  • Electric lamp lit from a match
  • Types of lamps for home lighting - which are better and what's the difference
  • Plasma lamps - how they are arranged and work
  • Illuminated switch and LED lamps

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    Comments:

    # 1 wrote: fantaer | [quote]

     
     

    Nonsense is complete, the indicator, in the form of a screwdriver, can not be used in any case! Resistor malfunction = electric shock. All sorts of capacitive pick-ups, the indicator is on, try to understand for a nonsense, phase is not phase. You need to use ONLY TWO-POLE voltage indicators with insulated handles that periodically pass the insulation test, and these so-called indicators are rubbish!

     
    Comments:

    # 2 wrote: Vlad_K | [quote]

     
     

    I completely agree about the nonsense written here.

     
    Comments:

    # 3 wrote: Andrew | [quote]

     
     

    It is impossible to work with such an indicator screwdriver as shown in the figure. This is Mr.
    The bipolar pointer is, of course, not a bad thing, but if the zero burns out, it will not show anything and upon contact you will be energized. A screwdriver is still needed.
    I use in my work a SCREWDRIVER-INDICATOR RESANT 6885-48NS-SOUND
    Very comfortably. And check the phase without touching the wire. And under stress too. And at the expense of the bulb everything is correctly written.
    I, as an electrician with many years of experience, completely agree. They exploded in the hands more than once.

     
    Comments:

    # 4 wrote: Dmitry Aleksandrovich | [quote]

     
     

    Hello! My opinion: sometimes a test lamp is necessary. For example, to find out: is there a "live" phase or zero on a given wire, or, during its length, is some kind of load turned on, or, simply, a poor-quality contact in the circuit? The multimeter and indicator, due to their high input resistance, are useless in this case. Also, with a lamp it is possible to bridge "suspicious" sections of circuits without fear of short circuit. A lamp that is turned on instead of a blown fuse can be successfully used to find a short circuit (energized, of course). With all this, in order to prevent trouble with the explosion, you first need to use a multimeter. Ah, the lamp is a complement to it.

     
    Comments:

    # 5 wrote: Electrician | [quote]

     
     

    Nobody forbids using a two-terminal device to check for the absence of phase by taking one probe in your hand, there the same 1MΩ resistor is installed. In general, any indicator should be checked by touching the parts knowingly under current. Neon never fails by the way, but an electronic screwdriver with an LED is nonsense!

     
    Comments:

    # 6 wrote: Oleg Ivchenko | [quote]

     
     

    The control lamp is necessary constantly. Is the restriction / prohibition on its use so hopeless?

    For twenty years I have been using safe control, which I did so.

    To cover 380 V, two refrigerator light bulbs are connected in series (440 V). For mechanical protection, the bulbs are placed in an aluminum sleeve (for me, from an unusable electrolytic capacitor). The circumference of the sleeve is drilled with holes covered by flexible transparent plastic. A copper probe (open only near the tip) is inserted on the plus side, and a well-insulated wire with a crocodile clip comes out on the opposite side.

    Specification: “From the side of the positive terminal” - this means the positive terminal of the capacitor shell.

     
    Comments:

    # 7 wrote: Andrew | [quote]

     
     

    And I use neon control and recommend it to everyone. It does not burn out for many years.

     
    Comments:

    # 8 wrote: Alexander | [quote]

     
     

    People, wake up! Bipolar testers show and just create the phase and load))) Google FLuke 110, for example))

     
    Comments:

    # 9 wrote: Kolya | [quote]

     
     

    The lamp from the "spot" lamp, albeit in a glass, but very reliable housing. And if there are fears of connecting to 380 V, then two consecutive bulbs will save the father of Russian democracy.

     
    Comments:

    # 10 wrote: Igor | [quote]

     
     

    Turn on the lamps in series from the refrigerator at 15 watts each and everything will be fine, only you need to protect the spiral from breaking the bulb from insurance. The most tested way to test under load and not be afraid of interference.

     
    Comments:

    # 11 wrote: Alex gal | [quote]

     
     

    Everything can be used and "otvetki" and control lights))) The main thing is wisely and where it is needed. Control lamps were used even when there were no normal devices - it was cheap and simple. In the rules of those years there was a requirement not to use such "controls" where it is possible to get to a voltage higher than the rated voltage of the lamp.

    The option of two lamps in series is inconvenient, even if their size is 10-15 watts, the control will be too big, but it is safer. I remember using a very long time fittings with a small control incandescent lamp from an old control panel with a 380V resistor. With a 5-10W resistor, the size is small, no explosions, everything is closed. The only drawback in the 220V sun is hard to see through the stained glass of such controls.

    Therefore, modern appliances will be better than old homemade products, especially primitive ones.

    Their danger in the article, of course, is greatly exaggerated, because work in installations with life-threatening voltage has always required and will require increased attention to their own safety with any devices.

    Nevertheless, it is, and if I was working in electrical installations now, I would definitely purchase something special from the modern one.

    But in principle, if 20-30 years ago instead of the Ts4315 or Ts20 someone gave me a small multimeter (which is now like dirt for ridiculous money), then a screwdriver indicator would be enough for him to pair)))

     
    Comments:

    # 12 wrote: Sergey Merzlyakov | [quote]

     
     

    When operating in AC networks, turn on the test lamp in series with the diode and nothing will explode. Sometimes control is needed, any indicator will show the voltage even with micro-point contact, and even without it, and a fairly significant current flows through the lamp, even with the diode, and if the circuit is half open, the lamp will not light up, or it will shine very badly.