Electrical Superstitions?? hehe

1) Tuwing kumikidlat ay takot ang mga taong baka pumasok ito sa linya ng kuryente at mag cause ng sunog o aksidente sa mga appliances sa bahay. Andyan minsan ang tatawag ang boss sa isang building para patanggalin ang lahat ng nakasaksak na equipments kasi baka masira.

Maling paniniwala: Ang kuryente nga, sabi nila ay tamad. Kung saan ang pinakamalapit na pwede daanan ay dun sya pupunta. Halimbawa nalang ang isang tao sa gitna ng malawak na bukid. Sa ulan, kidlat at kulog, ang pinakamaingat nyang magagawa ay DUMAPA at magpaulan. Delikadong lumapit sa isang MATAAS na puno at sumukob kasi ang tendency ay pumunta ang kidlat sa pinakamataas na kahit ano na nakatayo.

Ang unang dapat makita ng taong takot sa kidlat ay kung ang kinaroroonang lugar ba ay mataas, o ang building ba ang pinakamataas sa lugar. Pero dapat din nyang tandaan na meron namang lightning arrester na andyan para proteksyonan tayo laban sa delikadong mga kidlat.

2) Minsan para macheck ang boltahe ng power supply ay gumamit ng voltmeter ang isa kong kakilala. Ang 220 V ay dapat pumalo sa 12 V para sa maliit na device na gagamitin nila kaya meron itong sariling transformer. At laking gulat nya, hindi 12 V ang nakita nya, 8 V. Meron bang dapat ipagbahala? Haruy..

Maling paniniwala: Ang kuryente ay pabago-bago ang boltahe. Ang nominal voltage nating 230V dito sa pilipinas o 115V sa ibang bansa gaya ng Japan ay isa lang numero. Ngayon ay pwedeng pumalo ang kuryente sa 230 or mas mataas pa, mayamaya ay pwede ring bumaba . Kaya acceptable pa din sa atin ang 220 at 240 na +10 o -10 V. Ang 8 V na nakukuha sa supposedly 12 V na labas ng kuryente ay di nakapagtataka. Pwede tumaas ito sa 12 V o bumaba, depende sa pumapasok na supply galing sa MERALCO o anumang utility company.

Fire Alarm System

Sunog! Sunog! Sunog!! =( sunog buhay tepok. haruy... kaya kailangan atin bahay fire alarm system.

Fire Alarm Systems

A home fire alarm system is usually part of a total security system providing burglary protection in addition to fire protection. Such a system supervises doors, windows, and spaces within the home for break-in and may provide monitoring services by dialing your telephone to report a fire or intrusion to a security office, where it will be reported to your local police or fire department.

Components of the System

These systems consist of a central control panel to which smoke alarms and heat detectors are connected, along with bells or horns that are activated when the system triggers an alarm. Other sensors associated with the burglary functions connect to doors and windows or monitor rooms for motion or body heat. The control panel operates from house power but also usually contains an emergency battery which can operate the system for about 24 hours during a power outage.

The basic requirements for the number and locations of alarms are exactly the same as with the self-contained alarms discussed previously. The difference is that a fire alarm system gives you more flexibility to locate additional alarms and additional bells or horns (or flashing lights, should a person in the household be hearing impaired).

Fire alarm systems that provide remote monitoring services can also be used to provide medical alert services. Here a person with health problems who lives alone carries a radio transmitter that can trigger the system in case they need assistance. Signals received at the monitoring station are identified by type (fire, burglary, medical alert) so that the proper response can be made.

Why Have a Residential Fire Alarm System?

The primary advantage of a home fire alarm system is increased reliability and the ability to place alarms and bells exactly where needed. However, the reason most people have them is that they wanted a burglar alarm system and the cost of adding fire alarm features to a residential burglary system is relatively small.

Another advantage is that they are the only way to obtain remote monitoring services. This becomes important in cases where family members may not be capable of escaping from a fire without assistance. For example, if you have an older or physically impaired person in your home and a fire started when no one was home to assist that person, alarms alone might not be enough to assure their safety.

A feature of most monitoring services is the ability to keep special information on the residence which comes up on the computer screen whenever an alarm is received from that home. Thus, if there is a disabled person in the home who needs special assistance this fact will be known to the operator and can be passed along to the fire department when they are called.

http://www.usfa.dhs.gov/downloads/pyfff/alarmsys.html

Electrical Safety Tips

Parang matchsticks, ang konting spark ay pwedeng makagawa ng malaking sunog. Sabi nga din, ang kuryente ay tamad. Kung saan ang pinakamadali at pinakamaikling daanan para sa kanya, yun ang kanyang pupuntahan.

It tries to find a conductor, or something that it can pass through to get to the ground, like metal, wet wood or water. Your body is about 70% water, so that makes you a good conductor, too. For example, if you touch an energized bare wire or faulty appliance while your feet are touching the ground, electricity will automatically pass through you to the ground, causing a harmful, or even fatal shock.

It only takes one mistake to spark an electrical fire, but simple prevention measures can be effective solutions.

1) APPLIANCES

• Unplug unused appliances and stow cords safely out of reach of pets, young children or hazardous situations.

• Appliances that generate heat, such as clocks, televisions and computer monitors, should be given several inches of clearance all around for good air circulation and cooling. Do not drape clothes, toys or other items over warm appliances.

• Always follow appliance instructions carefully, and do not attempt amateur repairs or upgrades.

• Keep all electrical appliances away from water such as sinks, bathtubs, pools or overhead vents that may drip.

• Do not operate any electrical appliance with wet hands or while standing in water.

Cords

Every electrical appliance has a cord, and many homes use extension cords to increase the range of electrical outlets. Ito naman ang mga dapat tandaan pagdating sa mga electrical cords.

• Check cords regularly for frays, cracks or kinks, including power tool cords, holiday lights and extension cords.
  

• Cords are not be jump ropes, clothes lines or leashes, and should never be used for anything other than their intended purpose.

• Cords should be firmly plugged into outlets – if the cord is loose and can pull out easily, choose a different, more snug outlet.

• Do not staple or nail cords in position at any time; if the cord does not remain where desired, use tape or twist ties to secure it.

• Cords should not be placed beneath rugs where they can become a trip hazard or where frays will not be noticeable. Furthermore, covering a cord will prevent it from keeping as cool as possible.

• Do not make modifications to a cord’s plug at any time – do not clip off the third prong or attempt to file down a wider prong to fit in a different outlet.

• Extension cords are a temporary solution only and their use should be minimized whenever possible.

Outlets

Every cord has to plug into an appropriate electrical outlet, but these tempting niches are inviting to unwelcome objects that can cause shorts and fires. Use these electrical safety tips at home to keep outlets safe.

• Block unused outlets by changing to a solid cover plate or using childproof caps.

• Do not overload outlets with multiple adaptors or power strips; relocate cords instead.

• Never put any object other than the appropriate size plug into an outlet.

• Install ground fault circuit interrupter outlets in potentially hazardous areas such as near pools, crawlspaces, kitchens, bathrooms and unfinished basements.

• Keep all outlets properly covered with secure plates that cover all wiring.

Light Bulbs

Light bulbs are the single most common electrical fixture in homes, and proper light bulb safety can keep them from becoming a common electrical hazard.

• Use bulbs that have the correct wattage requirements for each fixture -- using a higher wattage bulb can cause the fixture to overheat.

• Consider switching to more efficient compact fluorescent bulbs that provide the same level of light at a lower wattage level.

• Always screw bulbs in tightly; a loose bulb can cause sparks or shorts.

• Be sure to unplug or turn off a fixture completely before changing light bulbs.

Ceiling Fan Ngayong Summer

Fans don't make the air cooler! They work by blowing away the envelope of warm air that surrounds your body.

As a living creature, you generate heat. A lot of it. As that heat slowly radiates away from your body, it creates a pocket of hot air that surrounds you. It's like you're being insulated by an invisible bubble of heat. What fans do is to push that hot surrounding air out of the way.

This is why blowing on hot food cools it off. It's not that your breath is especially cool, it's that you're blowing the heat off the food.

If you're sweating at all then the fan also cools you by speeding up the evaporation.

So now that you know that fans don't make the air cooler, you can see that there's no advantage to leaving the fan on when you leave the room. Fans don't lower the temperature in the room at all.

By the way, a typical 36" / 48" / 52" ceiling fan uses about 55 / 75 / 90 watts of electricity respectively (less on slower speeds).

Electrical Appliances in flood

Readiness, Response and Recovery.

Emergency 101

Before entering a home after a flood, be sure that the electricity has been
completely shut off at the panel. If you are not certain how this is done, get a licensed electrician or authorized service person to do this for
you.

Pag meron pa ding tubig sa paligid ng appliances, iwasang pumunta malapit dito lalo na't di sigurado kung nakashut off ang appliances. Pweding masave ang appliances pero kailangan munang PATUYUIN ang mga ito bago gumawa ng hakbang.

SAFETY MEASURE:

NEVER allow the connection between the machine's power cord and the extension cord to lie in water.
ELECTRIC CIRCUIT BREAKERS AND FUSES can malfunction when water and silt get inside. Discard ALL circuit breakers and fuses that have been submerged.



Appliances in flood can be classified into two:
a) submerged in water
b) just wet by rainwater

Appliances submerged in water are often NOT REPAIRABLE but the appliances that have been saved and not flooded are often REPAIRABLE.

Water, especially dirty floodwater, na puno ng putik, causes many problems (lalo na pag nakapasok ang mga ito sa motor windings, electrical contacts at mga switches). Pwedeng kalawangin ang mga ito at di na gumana.

Kung nakapasok naman ang mga ito sa insulation, ang mga appliances na mga heater o cooler gaya ng electrical ranges, freezers or ref ay pwedeng di na rin gumana nang maayos at magkaroon ng masangsang na amoy.

Appliances damaged by water can sometimes be made functional, but they will likely have a shortened life expectancy. Depende kung gaano katagal ang mga appliances bago sila nabasa, ang buhay ng mga appliances ay umiikli..

1) How to CLEAN APPLIANCES

Never hose them down!! Ang mga appliances ay di gamitan ng hose ng tubig para malinis kaagad. Keep in mind that electricity and water should not mix..

Pwedeng gumamit nalang ng basang pamunas na madaling matuyo para alisin ang dumi sa appliances. Pwede ding gumamit ng electric fan to increase airflow.

You can also try using CONTACT CLEANER ( solvent na iniispray at madaling mag-evaporate gaya ng isoprophyl alcohol ) para sa mga contacts ng switches.


2) GETTING RID OF ODOR

If an odor persists, wash with a solution
All we need are the following:
isang kutsarita ng baking soda
isang 1/4 gallon ng tubig
isang cup ng suka

Pwede ding isang cup ng household ammonia kada isang galon ng tubig.

Frequently asked questions, powerline!!

1) Are power lines insulated?

Kala ng karamihan sa atin, ang power lines o yung malalaking kable na galing sa utility company papunta sa mga poste papunta sa mga consumers have INSULATION MATERIAL around them kagaya ng mga electric cords ng mga applicances.

FYI, ang high voltage na linya ay HINDI INSULATED. The protective covering around it is not an insulation. It only PROTECTS THE LINE FROM WEATHER CHANGES.


Ang mga appliances natin ay gumagamit ng 110 o 220 Volts.
At that level, insulation material is practical. But at 7,200 Volts o higit pa, ang insulation material ay masusunog lang dahil di nito kakayanin ang mataas na kuryente, right??

And if the material was substantial enough to handle the HIGH VOLTAGE, it would be too expensive, TOO THICK and TOO HEAVY to USE.

2) Why can birds sit on power lines without being hurt, when it would kill me to touch that same line?


Ang kuryente daw ay tamad, By nature, hinahanap ng kuryente ang PINAKAMADALING PATH papunta sa ground.

When a bird lands on the line, her body becomes charged--for the moment, it's at the same voltage as the wire.

Kaya lang, di sya makukuryente kasi mas pipiliin ng current na dumiretso na lang sa copper wire ng power line kaysa pumasok o mag-detour sa katawan ng ibon na less yung conductivity.

Makukuryente lang ang isang ibon KUNG ang isang paa nya ay nasa conductor at ang ISA ay nasa isang path to ground.

Kaya kung ang isang squirrel ang dumaan sa power line, makakasurvive sya PERO makurkuryente din the moment na mahawakan o maapakan nya ang (grounded) transformer na nasa dulo ng wire.


Ngayon, if in any case, ang isang tao ay umakyat sa puno at humawak sa power line, madaling makakapasok ang kuryente sa kanya, papunta sa puno, papunta sa ground.
=S

Malay sa relay na yan. =( A BIG NO NO. (part 3)

Anong mangyayari pag naconnect ang isang AC relay sa DC?

Ang isang AC relay coil has both inductance and resistance limiting the current.
Generally, ang AC relay ay nakadesign nang may mas mataas ng current kesa sa DC
(kasi mas less efficient ang AC). Pag naikabit ito sa DC at hindi sa AC, magkakaroon ng mas
mataas na current pa rin. The relay would operate properly (for a while) but would eventually
fail due to the coil overheating. Depending on ambient temperature and the specific relay,
failure could occur in minutes, or might take years.

Malay sa relay na yan. =( A BIG NO NO. (part 2)

We can say that a relay is A SPECIAL KIND of switch.

Here are two examples kung bakit kailangan natin ng relay.


On the upper part is a diagram for automobile circuit.

Pag naka-on ang ignition key ng sasakyan, it allows electricity to flow to the starter solenoid ( yun ang relay) which then connects the battery to the starter motor.

So why do we need the "middle man" relay? Pwede ba nating e-eliminate na lang ito at iconnect ang ignition wires sa +battery terminal at yung isang wire sa motor starter naman?

The important point here is that the electromagmet is using a small amount of current to control a large amount of current to the starter motor. (Remember that the electromagnet and the switch are NOT connected electrically).

Have you noticed that all of the wires (except the ignition wires) are purposely drawn with thick lines? That's because some circuits (like the starter) require tremendous amount of current. (kaya kailangan din ng mas malaking kable).

(If you look at an automobile's battery cables, you will notice they are quite thick.)

Pag maliliit na wire ang ginamit natin, di nito kakayanin ng insulation nya ang mataas na current, kaya masusunog ito, at uusok.

We do have a second choice. Pwede tayong gumamit ng malalaking kable mula sa battery gamit
ang heavy duty ignition switch. However, do you think it would be easy to squeeze cables into the steering column and squeeze in a heavy duty switch too?

BURGLAR ALARM SYSTEM

Referring to the diagram, let's trace the electrical flow.

Kung makikita nyo, mula pt. V2, pupunta sa "C". Mula sa negative battery terminal, pupunta sa V1, tapos sa V2, at dahil tuloy tuloy ang alarm loop, pupunta sa "C" at pagkatapos ay sa positive battery terminal na. Sa circuit loop na 'to, dadaloy ang current sa electromagnet causing the common terminal to switch contact mula "C" patungo sa "B" At dahil walang contact sa A, the siren will not make any SOUND.

Pwedeng lagyan ng isa o mas maraming magnetic switch in series sa alarm loop para magkaroon ng warning signal o alarm sound. Kaya lang, ang mangyayari dito, tuloy-tuloy nga ang kuryente mula pt "C" to pt. "A" hanggang sa siren, NGUNIT HINDI sa electromagnet.

Alarm Circuit 1 does suffer from one serious flaw. Can you see what it is? Pag nareconnect ulit ang alarm loop, madidisconnect lang ang siren. This is a VERY IMPRACTICAL WAY AND NOT RECOMMENDED TO ANY ALARM SYSTEM. The siren goes off! Kung nabuksan ng isang magnanakaw ang pintong me magnetic switch nang pwersahan, sasarhan lang nito ulit ang pinto at di na tutunog ang siren.


Para maging efficient sa tao, kinakailangan natin ng isang device na pagproprovide ng additional contacts na mag-aallow ng isang circuit na gumana habang ang isang circuit ay putol. At yun ang nagagawa ng transfer mechanism ng common contact ng isang relay. =)

POWER SYSTEM

Ang power distribution ngayon at ang mga control systems are far more complex kesa sa dati.

They are designed with MULTIPLE LEVEL of redundancy, na ginagamitan ng PLC, para sa back up at emergency at inputs para sa multiple building systems.

Una, ano nga ba ang PLC?

Ito’y isang digital computer used for automation of electromechanical assembly lines, amusement rides, or lighting fixtures. processes, such as control of machinery on factory

At ano ano ba ang mga pwede mangyari in case ng isang EMERGENCY or power outage sa distribution system????????

Well, pwede magkagulo!! Below is an example of how electricians react to emergencies. Pitong oras silang nagkaroon ng isyu sa kuryente na pwede sanang masugpo ng dalawampung minuto kung natrain lang ang mga electricians ng dapat nilang gawin.

10:30 A.M.

Biglang nawala ang kuryente.

Dahil merong anim na UTILITY LINES para sa facility, mula sa iba’t ibang substation, alang back up na generator na nakainstall. Napag-alaman ng facilities manager na APAT na circuit breaker ang open. Pano nangyari ito????

The MAIN TIE AUTO-TRANSFER SYSTEM is designed for open transition transfers. Ang mga relays ang nagsisilbing sensor para sa LINE VOLTAGE at nakikipagcommunicate sa ating PLC.

Ang PLC naman ang utak ng control system na nabubukas ng MAIN o ng BREAKER TIE para marestore ang service to the load.

Ang dalawang natitirang power source ay ang emergency lines na lang.

Step 1) Both services ay ginawang MANUAL MODE ng mga electrician in attempt na maclose yung mga ito manually. One at a time, the electricians tried to close them,pero nagtritrip agad ang mga ito. Ibig sabhin, me problema nga… tsk tsk.

10:50 A.M.

Step 2) A second attempt succeeds, and one main in each service is closed. Power is restored to part of the facility. Kaya lang, hindi nacloclose ang B main breaker. (So ito siguro ang me problema.)

Step 3) Having already closed the TIE at MAIN A, the electricians tried closing again B main breaker. Ang resulta, both the TIE BREAKER at ang B MAIN BREAKER ay nagtrip ulit at nagopen and circuit. The maintenance manager reclosed the B-main at this time, it REMAINED CLOSE. (whew! hehe)

Step 4)

With power partially restored, nagdecide ang maintenance crew na hayaan na lang muna ang power system at magpatulong sa iba. Dalawang contractor electrician na nag-install ng mga ito ang pumunta doon.

3:30 P.M.

Step 5) The contractor's electricians looked over schematic drawings for more than two hours. Kaya lang, narealize din nila na din nila kaya ang problema. Tinawagan nila ang Manufacturer mismo ng circuit breakers at sinabihan pupunatahn sila dalawang oras pagkatapos tumawag .

5:15 P.M.
The Square D Services representative arrives.

5:25 P.M.
All power is restored and production resumes.

In this distribution system, we have the HIGH VOLTAGE SWITCH na nagsusuply ng 13.8 kV
galing sa utility company. Pwede itong 150 ampere delta connected
power to two 2000 kVA
dry-type transformer.

At ano nga ba ang dry transformer????

Well, ganito yun.

Ang Dry-Type Transformers ay ginagamit sa
loob at labas ng isang building, eskwelahan, ospital,
commercial building at iba pang lugar na
nangangailangan ng dependable power supply.

Dry-Type Transformers are available for voltages
up through 34.5 kV (although the most common
upper limit is 15) and KVA ratings up through 10,000 (with 5000
as the usual limit). Ang dry type tranformer ay gumagamit ng hangin
para mapanaliting tuyo, lowering health and environmentally
concerns.

Ang dry type transformer naman ay connected sa MAIN TIE CIRCUIT BREAKERS.
Gamit ang PLC, nagkakaroon tayo ng automatic operation para makasigurong
magkakaroon pa rin ng kuryente ang BUONG SWITCHBOARD LOAD kahit ang
isang main supply ay mawalan.

Warning: "disconnected neutral"

Ang disconnected neutral at tinatawag ding open neutral fault condition. Ito'y nangyayari pag nadisconnect ang neutral wire sa main power supply


PERO nakakonekta pa rin ang hot wire sa panel at habang umaandar ang electrical loads, katakot takot din ang pwede mangyari sa ating mga appliances . Subukan mong gamitin ng test screwdriver na merong neon lamp sa neitral wire, ang lamp indicator ay iilaw pa parang live wire na din ang neutral wire. At bakit nagyayari ito???


Actually merong napakaliit na current na dumadaan sa neutral wire galing sa Live supply via the plugged-in appliance(s) to the Neutral wire.


If you unplug all appliances, lights and whatever else may be connected to the circuit, ang neutral wire ay ala na din current because there is no longer any path from it to the Live supply. Di din magtritrip ang circuit breaker kasi ang current na dumadaan mula sa live via sa ating mga load papunta sa neutral ay napakaliit para madetect ng ating circuit breaker.

A "Disconnected Neutral" fault condition ay NAPAKA UNSAFE kasi maaaring tayong maaksidente dito at makuryente while trying to find out why no appliances work samantalang nakaplug naman ito sa outlet.

FYI: Disconnected Neutral (Open neutral)" fault condition

Paano pag ang NEUTRAL WIRE ay energized pero hindi nagtritrip ang circuit breaker?

Ito'y nangyayari lamang KAPAG ang neutral wire ay hindi nakakabit sa main power supply samantalang ang Line or "hot wire" para sa curcuit are konektado pa rin sa panel, at ang mga appliances are nakaplug sa mga outlet.

Pag hindi konektado sa main supply, dadaaanan pa din ito ng kuryente sa twing umaandar ang mga electrical loads natin at dahil kailangan natural sa kuryente ang maghanap ng path to earth, delikado sa tao sa mahawakan ang neutral wire na tulad nito.


Walang ORDINARYONG circuit breaker sa OPEN NEUTRAL FAULT CONDITION ang magtrireip o MAGSHUSHUTDOWN kasi ang line-to-neutral na current ay HINDI GANUN KATAAS.

In that situation, if you put a voltage indicator, such as a test screwdriver with a neon lamp onto the Neutral wire it will glow just as if it was Live, because it is being fed with a very small current coming from the Live supply via the plugged-in appliance(s) to the Neutral wire.

If you unplug all appliances, lights and whatever else may be connected to the circuit, the Neutral will no longer seem to be Live because there is no longer any path from it to the Live supply.


Even if there is a GFCI or an RCD in the circuit that too is unlikely to trip in this situation because the test current is so small and is of the same size - an equal current flow - in both the Live and the Neutral wires.

A "Disconnected Neutral" fault condition is VERY UNSAFE because somebody who does not know about the danger could easily touch the Neutral wire and get a bad shock whilst trying to find out why no appliances work when they are plugged into a circuit that actually has such a "Disconnected Neutral" fault condition.