MAINIT na LINYA

Pano pag ang isang linya ay MAS MAINIT kesa sa iba??

1) Una tingnan muna kung unbalanced ang circuit. Isa isang tingnan ang amperaha at kung mas mataas ito kesa sa iba.

2) Tingnan kung MALUWAG ang terminal. Pag maluwag kasi ang dinadaluyan ng kuryente, chances are, exposed ang wire, may tendency magleak ang current, kakalat ito, hindi masyadong nakokontrol ang circuit at mas iinit ang wire.

3) Idouble check baka me sunog na part. Sakaling naputulan na ang kable dati pa, nung nasunog ito, siguraduhing LAHAT NG SUNOG ay wala na dun. Kahit gaano kaunti ng sunog pag naroon pa rin sa circuit, maaaring magdulot pa rin ito ng problema.

Note: pag me sunog na area sa kable, di nakakadaloy nang maayos ang kuryente, nagtatambak (natratrapik?) sa isang lugar kaya umiinit. Katagalan, ang kaunting sunog ay lalaki nang lalaki hanggang sa bumigay ang kable. Lalo pa kung ito ay nasa dulo, masusunog ang terminal sa breaker. =)

Makukulay na Wires

Ang pagtrip ng MAIN BREAKER o pagkuha ng MAIN FUSE ay isa sa pinakaunang dapat gawin pag merong pagkakaabalahan o dapat kalikutin.

Pwede ding gumamit ang kahit na sino ng neon tester o screwdriver na umiilaw pag itinatapat sa wiring na live.

At para miwasan ang anumang pagkakamali, pwede ding tingnan ang kulay ng mga wire.

Sa electrical, karamihan ay COLOR CODED.

1) White wires - almost always connect to other white wires or to chrome terminal screws on switches and receptacles.

2) Black wires always signify “hot” wires that conduct electricity to an outlet or switch. These are never to be utilized for a ground or neutral connection.

3) Red wires also signify “hot” wires or switch legs. In 220-volt installations, the red wire is considered the second “hot” wire.

4) Blue and yellow wires are also used for “hot” wires, usually being pulled into a conduit. Blue is usually used for travelers in three way and four way switches or as switch legs in lights and fans.

5) Yellow wires and typically used as switch legs to control switched outlets.

5) Green and bare wires and only used as ground wires. They will ground what you are working on and will normally be bonded to appliance connection and junction boxes for safety.


Madaling malaman ang mga dapat at hindi sa electrical wiring. Sa bawat kulay na meron ang isang wire, ito'y nananatiling palatandaan kung delikado ito o hindi at kung saan ito nakaconnect sa isang circuito.

Inside the BIG BOX

Parang sa larong CHESS, ang bawat bahagi ng magnetic control ay may kanya-kanyang operasyon. Bawat isa ay nagtutulungan para madepensahan ang kanilang hari, TAYONG MGA TAO.

MCC, 440 V, Free-standing in Nema I enclosure and to contain the ff:

Main: 700 AT, 3P, MCCB

Metering:
1 - Digital multimeter
5 - Cylindrical fuse
3 - current transformer

Ang main circuit breaker ay mahahalintulad sa isang reyna. Sya ang pinakamalaking proteksyon sa control circuit. Sya ang humaharang sa mga aksidenteng pwedeng mangyari.

Ang Digital Multimeter naman ang BISHOP. Sya ang kanang kamay ng CIRCUIT BREAKER.
Katulad ng bishop, ito'y nagsisilbing tagamonitor sa daloy ng kuryente. Iba't ibang klase ng importanteng impormasyon ang pwedeng makita dito kasama na ang boltahe, amperahe, power, hertz at iba pa)

Ang mga fuse naman at current transformer ang mga pawn. Bilang auxiliary devices, sila ay tulong para sa malaking equipment gaya ng metro.


to be continued...

Mga Tao sa Likod ng ating Electrical Convenience Ngayon

• Ang pinakaunang electrical engineer na nabuhay noong 17 th century ay si WILLIAM GILBERT, isang scientist at natural philosoper. Sabi nga , siya ang father ng electricity at magnetism.
  

• William concluded that the Earth was itself magnetic and that this was the reason compasses point north (previously, some believed that it was the pole star (Polaris) or a large magnetic island on the north pole that attracted the compass). He was the first to argue, correctly, that the centre of the Earth was iron, and he considered an important and related property of magnets was that they can be cut, each forming a new magnet with north and south poles.

• In his book, he also studied static electricity using amber; amber is called elektron in Greek, so Gilbert decided to call its effect the electric force. Sya ang gumawa ng unang electroscope, gamit ang isang karayom.

• Ang pinakaunang tao naman na gumamit ng word na ELECTRICITY naman ay si Sir Thomas Browne, isang manunulat, Ang salita ay galing sa LATIN word na electricus, meaning "like amber".
  

• Sinundan si William Gilbert ni Alesandro Volta, isang physicist, na syang nakagawa ng BATTERY o ng unang electric cell. Sya ang nakadiskubre sa electric capaitance (C), sa charge (Q) at sa electric potential (V). ( Q = CV)

• Di rin pwedeng mawala sa listahan si ginawa ni Benjamin Franklin sa kanyang researches. Sya lang ang bukod tanging nagpalipad ng saranggola habang umuuln ng malakas at nagpatunay na ang kidlat ay isang klase ng kuryente. Dun din pumasok sa kanyang mga pagsasaliksik ang teorya sa grounding at marami pang iba.
  

• Pagkatapos sa kanya ay si George Ohm, isang German physicist at guro, na sya namang nagexplain ng pagkakaiba ng electric current at potential difference sa isang conductor na nagsimula ng electrical circuit analysis. Sikat ang kanyang OHMS LAW V = IR, at mula sa kanyang mga nagawang principle, ay ang applications na ng electric current.

• Andyan din si Michael Faraday, ang nag-imbento ng electric motor. Sa kanya nagsimula ang electromagnetic induction. Isang chemist at physicist, pinaghalong nya ang dalawang science at nabuo ang electrochermistry.
  

• Si Nikola Tesla naman kung saan pinangalan ang unit ng electromagnetic flux, ang "tesla", hehe. Sya naman ay nagconcentrate sa electromechanical engineering. Sa AC machines at sa polypahse, panalong panalo tayo sa kanyang mga ibinahaging kaalaman.

• Si Thomas Edison naman ang pinakapaborito ko. Siya lang naman ang nakaimbento ng motion-picture camera at ang nagdala ng liwanag sa ating kabahayan sa kanyang naimbentong "ELECTRIC BULB". At an early age, Thomas Edison developed a hearing impairment, pero di ito naging hadlang para di sya magtagumpay. Napunta sila sa Michigan ng kanyang pamilya at dun ay nagtinda sya ng mga candy, newspaper at mga gulay. At dahil sa likas na madiskarte, ang maliit na businessman ay swerteng napasok sa GENERAL ELECTRIC, isang malaking company. Quotable quote: We will make electricity so cheap that only the rich will burn candles." =)

Automatic transfer Switch, time delay???

EMERGENCY!

Dalawang supply sa ATS, isa galing sa utility company, isa galing sa generator para sa emergency power supply.

In case of any undervoltage, overvoltage, loss of phase, or total power failure, ang generator ay gagana after a PRESET TIME DELAY.

Then once na nastabilize ang generator voltage, that's the only time na ang UTILITY ACB ay mag-oopen o madidisconnect, at ang GENERATOR ACB ay magcloclose.


NORMAL...

When the utiility power returns, the utility ACB will IMMEDIATELY BE CLOSED.

However, in this case, hindi agad-agad magdidisconnect ang generator.

Magkakasabay pa din sila.. parehong aandar ang dalawang ACB and after a preset time delay (after magcool down ang generator), that's the only time that the GENERATOR ACB will be OPENED and disconnected again.

Measuring Instruments in the Panelboard

1. Frequency Meter

Ø Measures on how many times an event occur. This frequency meter is usually refrred to as counter. Frequency meter is connected in series with the generators. A problem also with the use of an frequency meter is the need for the meter to be inserted into the circuit and become part of it.

Warning: Mistakenly placing it in parallel with a circuit will blow the fuse, possibly damaging the meter and causing injury. In AC circuits, a current transformer converts the magnetic field around a conductor into a small AC current.

2. kVAR meter

As its name implies, kVAR meter measures or present the amount of reactive power present in a circuit. As we all know, KW and KVAR are confusing.

It seems that usually, one thinks that if KVAR's in a system is equal to zero, then there is no power flowing. (maling mali po). This person fails to understand that real power and apparent power are not the same for a system operating with a no unity power factor. This apparent power is simply circulating power due to the phase shift between the source and the loads. This additional power that appears to be flowing requires the equipment to be rated higher than that for a system operating at unity.

Obviously these circulating currents are really producing no useful work. It is the job of the EE or the power plant operator to correct the load reactance as close as possible to unity to increase efficiency and reduce operational costs. Thus, kVAR meter is very much helpful in the power plant.

3. Kilowatt Meter

Ø The kilowatt-hour meter is designed to reliably, and accurately measure the electrical energy (kWh) used in your home or place of business.

Ø When you look at the face of a kilowatt-hour meter, across the middle you will see a metal horizontal disc that turns when energy is being used. This disc is designed to turn like a motor wheel when energy passes through the meter, and it is calibrated so that one rotation of the disc corresponds to a specific number of kilowatt-hours. This means that depending on the meter make or type, one meter may spin twice as fast as another to register the same kilowatt-hours.

Ø The kilowatt meter and kilovolt-ampere meter measure the power (demand) delivered to the facility being metered averaged over a short duration of time. These facilities are larger users of power than residential or small commercial energy use

4. Synchroscope

Ø A synchroscope indicates when two AC generators are in the correct phase relation for connecting in parallel and shows whether the incoming generator is running faster or slower than the on-line generator. The synchroscope consists of a two-phase stator. The two stator windings are at right angles to one another, and by means of a phase-splitting network, the current in one phase leads the current of the other phase by 90°, thereby generating a rotating magnetic field.

Ø The stator windings are connected to the incoming generator, and a polarizing coil is connected to the running generator. The rotating element is unrestrained and is free to rotate through 360°. It consists of two iron vanes mounted in opposite directions on a shaft, one at the top and one at the bottom, and magnetized by the polarizing coil.

Ø If the frequencies of the incoming and running generators are different, the synchroscope will rotate at a speed corresponding to the difference. It is designed so that if incoming frequency is higher than running frequency, it will rotate in the clockwise direction; if incoming frequency is less than running frequency, it will rotate in the counterclockwise direction. When the synchroscope indicates 0^o phase difference, the pointer is at the "12 o’clock" position and the two AC generators are in phase.