Electrical Measurement & Lighting Essentials
Tension or Measures of Potential Difference
a) Measure the voltage or potential difference (volt) measured tension. This is formed inwardly by a coil with many turns and a small section, resulting in large internal resistance. It is connected in parallel. Voltmeters are used to measure three-phase switches.
Measures of Intensity (Ammeter)
b) Measures the current. It consists of a coil with few turns and large sections. Its connection is in series to measure the desired intensity. Three-phase switches are needed for amperes.
Measures of Electrical Resistance
c) Measured in laboratories using bridges and daily with an ohmmeter. The ohmmeter consists of a galvanometer that measures the scale and does not give the value in ohms, plus a battery that serves as the power supply in series. The battery runs to allow current flow through the device and measure the resistance. To measure resistance, isolate the measuring element from the network. It is measured by placing the tips of the claws on the ends of the resistance being measured.
Measures of Power, Power Factor, and Frequency
a) Power
In AC, we have three types of power: P.active (represented by P), which is the useful work produced and measured in watts (W); P.reactive (denoted by Q), which is present in AC circuits with inductors and capacitors and does not do useful work (VAR); and P.apparent, which is the vector sum of P and Q, with its unit being VA (volt-amperes). Power is measured continuously with a power meter. The meter consists of two coils, an ammeter and a voltmeter, which correct the gap between voltage and current in alternating current and measure the active and reactive power. A varmeter operates similarly but introduces a 90° gap between U and I in the voltmeter coil. For inductors and capacitors connected to an ohmic resistor, a wattmeter is used.
b) Power Factor (Phase Meters)
Gives the gap between the tension and intensity, measuring the cosine of fi. Phase meters can be inductive or capacitive. This applies only to AC.
c) Frequency
The number of times a cycle is repeated in a second. Unit: Hz. Connects like a voltmeter.
Measure of Electrical Power
The power used over time. Measured by a counter.
Signaling Apparatus
a) Ring Bell or Vibration
Consists of an electromagnet, bell, hammer breaker armor. When the coil attracts the armature, the bell hammer hits, and as the armature separates from the circuit breaker, it returns to its place, closing the circuit again and repeating the cycle. Suitable for AC and DC. Often includes a lead screw on the breaker to change the sound.
b) Buzzer
Applies only to AC. Consists of an electromagnet and a U-shaped metal plate fixed to the coil’s core on one side, with the other part of the plate above the upper end of the electromagnet. It works by changing magnetic fields created by the electromagnet, causing the metal plate to strike the coil’s core due to the AC effect, creating a buzz. Usually has a screw to regulate the buzz.
c) Timbre Ding-Dong
Typically produces two musical notes, ding and dong, one when the button is pressed and another when released. It consists of an electromagnet with a coil and core attached to a dock and two layers of different temper or two distinct sound plates. When current passes through the coil, it attracts the core, causing a plate to strike and produce a sound. When the button is released, the core returns to its place via spring action and hits the second plate. It often includes a chamber to make the sound more pleasant. Pressing the button momentarily is sufficient for operation.
Equipment for Maneuvering Based on Electromagnetism
a) Step Relay
An electrical device operated from different locations using push buttons to control the power of several light points. It consists of an electromagnet, one or more contacts, and a mechanism for opening and closing them. Each time the coil receives a current pulse from a button press, it draws its core and closes or opens the electrical contact. A locking mechanism holds the contact in position after the current pulse. A new pulse changes the contact’s state. The electrical contact acts as a switch connecting multiple light points, and the coil can be operated from various locations.
b) Automatic Stairs
Allows stairs lighting from different angles using buttons and controls multiple light points. It includes a timer that automatically shuts off the lamps after a set time. It consists of an electromagnet, an electrical contact, and a timed release mechanism. The contact can be normally open (two terminals) or commuted (three terminals). Types include clockwork, pneumatic, thermal, and electronic. When a switch is activated, it closes the circuit through the coil, and the contact changes position until the timer disconnects. Three wires are used for lamps and push buttons, and four wires are used for lamps, push buttons, and a separate lamp (e.g., for a hole at the top of a building).
Accident Prevention
a) Accidents at work: Bodily injury or suffering resulting from work.
b) Prevention: Measures taken to avoid or reduce risks of disease and injury at work. Governed by the LPRL (Law on Prevention of Occupational Risks), which mandates that workers ensure their health and safety and that of others affected by their work.
c) Safety at work: Actions to combat workplace accidents. Inspection of facilities to determine risk levels and analyze solutions. Example: Scaffolding where falls or collapses can occur. Stairs where falls or breaks can happen. Ladders over 5 meters are not allowed; harnesses must be worn for heights over 3.5 meters.
TT Outline
In this distribution type, a point on the installation (usually the neutral or compensator) is directly connected to the ground. The masses of the reception facility are connected to a separate grounding from the feed’s grounding.
Intensity On
Overload occurs when there is a higher intensity than designed for a circuit or device. A short circuit happens when two different points connect without resistance. Fuses protect against short circuits and overloads. Fuses for small domestic power protect drivers and receivers from short circuits and overloads. They fuse with an intensity four times greater than nominal and protect against overloads.
Curves and Features (Circuit Breaker Curves)
Current spikes in a facility depend on the feeding receptor. Devices are needed to discriminate if these spikes are dangerous. Devices with the same curve have different characteristic times and act with intensity values for different magnetic cuts. Important values in the time-intensity curve include: In (rated current), Inf (non-functioning intensity), If (operation intensity), Ym (maximum intensity that should not cause magnetic trip), and Ym2 (minimum intensity causing magnetic trip). Different curves for circuit breaker trips include: B (magnetic shot between 3 In and 5 In, protects cables), C (between 5 In and 10 In, for high-intensity loads at startup), D (between 10 In and 20 In), ICP (between 5 In and 8 In, for power control switches), and Z (between 2 In and 3.6 In, for electronic circuits). Thermal trip operates between 1.13 In and 1.45 In (t <= 1h) and > 1.45 In (t < 1h).
Overvoltage Protection
Overvoltages from atmospheric discharges or maneuvers in transformation centers require combined protection, including coordination of equipment isolates, surge protection devices, proper installation, location, and grounding. A surge protector has high impedance and does not interfere with the installation. When voltage exceeds the nominal value, the protector goes to low impedance to ground, diverting the surge intensity. It is located near the ICP (Power Control Switch) for maximum effectiveness.
Protection Against Direct and Indirect Contacts
Aims to protect people and animals. Direct contact involves touching live parts. Indirect contact occurs when touching parts that become live due to appliance failure.
Earthing
Limits the voltage of metallic masses with respect to ground, ensuring protection performance and reducing risk during faults. The installation should include ground shots, a ground wire connecting the grounding electrode, a grounding terminal, and a protective conductor. Rods, tubes, and plates are used for grounding.
Degrees of Protection of Enclosures
: Surround is the q element provides protection to the material. There are two types of protection ip q consists of two one-digit number q will point after ip and q ik indicates the degree of impact protection is designated by number graduated from 0 to 10. LUMINOTECNIA FIGURES: a) flow q Light q is the light power radiated b) luminous efficiency eg q q is not all the energy to light a lamapra is used for the light but lost in calor.c tmb) candle light intensity, q is the amount of light emitted in one second by a light source d) q lux lighting level is the amount of light incident on a surface q e) q Luminance is the luminous intensity per unit area aparante of a light source is primary or secondary candela/M2 WAVELENGTH: the space between two points on a wave that is in phase. It is designated by the letter lambda (i Greek to revez with a stick that falls on the left) and expressed in meters. Drawing page 186. c = xf igriegalrevez dnd c is the propagation speed in m / s. Light is the portion of the electromagnetic espcetro the eye can perceive. The spectrum area is between wavelengths that are worth 380 and 780 nm, between ultraviolet and infrared band. The maximum sensitivity of the human eye is 555 nm.Incandescent LAMP: There are three types of incandescent gas without halogen, the halogen incandescent gas and special. A) are not using the normal-shaped bulb q holds for domestic and commercial lighting and its value is between 25 and 200 watts. Also this candle lamp is up to 60 W peak and q balloon is 60 to 100 w. And last the reflector. Features of incandescent lamps: the yield is below 10 to 20 lm / w. The color temperature is 2700 ° k and chromatic yield figure of 100%. last for a thousand hours unless the last q pressed glass 2000. The operating position is universal. No need to light them ekipo assistant. B) q gas used, usually take iodine, q reduces evaporation of the filament, with that lengthen the life of the lamp and we have more effectively. We metallic reflector halogen, halogen and sailing the globe and finally double capped. The characteristics of these are 30 lm / w, color temperature 3000 K th and last until 4000 h. c) special incandescent, that are for toys, cars, photography … DISCHARGE LAMPS: classified under fluorescent or mercury vapor low pressure of mercury vapor high pressure, light or mixed Mezco, metal halide, sodium vapor high or low pressure. Its operation electric current runs through the filament causing the filament, the current must pass through a gas or metal vapor, and are based on the phenomenon LUMINISENCIA. Velica is an electron collides with an atom high, passing some of their electrons to a level higher energy. The high level electrons in the atom successful return to his position and return the Q had seized power in the form of electromagnetic radiation. LUMINISENCIA BY ELECTRIC SHOCK OF A GAS: this phenomenon accelerates electrons through an electric field. We have a clear tube and inside there is gas, at its ends two electrodes connected to uninterruptible power supply. By applying tension existing free electrons inside the tube are attracted to the positive electrode. During his tour the electrons collide with gas atoms and produce luminisencia. Strobe effect: it consists of an optical effect that occurs when discharge lamps are fed with alternating current. When the voltage applied to the electrodes passes through zero, but lamapra tends to stop before it does the tension q takes a value determined and occur very fast light flucataciones. When we light round objects … .. eg wheels … q rotate at high speed sensation gives dq stand or move in steps. Cn incandescent lamp we see the movement of the wheel and the fluorescent q gives the sensation of this stop. To mitigate this effect will connect the various lamps of various stages of installation cn distribution network. Or by special assemblies monophasic networking groups. Fluorescent Lamps: electric lamps are mercury vapor atmosphere at low pressure and an inert gas lighting effect which is based on fluorescence phenomenon is a property of some substances, these transformed radiation no visible impact on them, visible. These fluorescent substances are powders that are in the inner wall of discharge tube.Constitution, namely, the discharge pipe, two caps with two-pin connection for connecting the electrodes in a filament, gas fill and fluorescent powders. The tube is designed to isolate the electrodes and the gas filling the environment, usually glass or quartz, coated with a fluorescent powder coating on the inside. You can have several forms straight, circular, etc … connection bushings are two located at each end of the tube fitted with respective pairs of pins, and connected to the electrodes. Fluorescent powders are transforming radiation into visible light, 90% of visible light emitted by the pipe is because of them. EQUIPMENT Fluorescent Lamp: a primer that is needed for the lighting of the lamp, has two sheets one is bimetallic, are inside a glass bulb filled with neon gas at low pressure. You have an anti-parasitic capacitor in parallel with this, the set is closed and isolated by a cylinder of which get two terminals to connect to the bait holder. We have one ballast (ballast) that is formed by a winding enamelled copper wire on a magnetic core. The purpose of this is to provide a voltage higher than the line to the lighting of the lamp. Besides limiting the arc current intensity at a good value for the lamp. There are different types of reactors. You have a bait holder which is the choke tube holders and one for each end of the lamp. A) The operation of the equipment, we close the switch, connecting the network circuit, the voltage is applied to the plates of the primer, the proximity of these is between them and the neon gas arc increases the temperature within the ampoule and deforms the bimetallic strip that bends and get stuck, now stay closed heating circuit and the current flowing through the two strands of the tube to make them incandescent. After a moment the temperature decreases and the bimetallic strip back into place abruptly, this makes the reactor lead to an overvoltage causing an arc between the electrodes of the tube and it gets so bright emission of radiation. The power factor lamps Download: because of the delay phase shift between intensity condolences to tension, there is a decrease of power factor is low lighting factor and that’s bad because there will be more intense in the supply line and higher voltage drop and line heats . The internal circuit is good fluorcente low power factor and abroad is good to stop. To fix that capacitors are used. FLUORCENTES TUBES WITH DIFFERENT ASSEMBLIES: simple connection when the value of the reactance tube and match. Two tubes in series with reactance example .. two tubes of 18 with ballast 36, the trouble is that if a pipe breaks or primer, it does the rest. SEVERAL separate tubes: used when several tubes keremos trigger a corresponding reactance or a luminary with multiple lamps, from one or more points. Connection duo: a luminaire with two independent ekipos q keremos correcting stroboscope effect. The capacitor connected in series with one tube produces a gap with the first thing it does not match the moments in which the voltage values become zero. DEVICES FOR CONTROL OF LIGHTING: time switch, q keep triggered the electrical installation during the time we give you. The proximity sensor that controls when the radio detects a movement action. And finally the twilight switch that controls the operation of an installation of lighting when the light level is not reached the set.