Wednesday, February 06, 2008

FAULTY ELECTRICAL WIRINGS - PART 4

GOING BACK TO BASICS




FAULTY ELECTRICAL WIRINGS - A CLOSER LOOK
(Fourth Part of a Series of Six)

By Doods A. Amora, PEE 1821
(February 2008
)

-----------------------------------------------------------



6.0: INTEGRITY OF ELECTRICAL INSTALLATIONS

“Poor workmanship or Un-workmanlike installations” are ‘substandard practices’.

When we declare something as “substandard”, it predicates that there should be some sort of a standard.

As standards shape the integrity of any system, what then is the electrical standard? In the Philippines, is it not the Philippine Electrical Code? The National Building Code (under the watch of the Office of the Building Official) and the Fire Code of the Philippines (Bureau of Fire Protection) - two of other community-related safety codes are in fact citing & referring to the Philippine Electrical Code in so far as electrical installations are concerned.

The term standard refers to design & installation norms or procedures set forth by an authority. In the Philippines, the Philippine Electrical Code (PEC) is the acknowledged standard reference for electrical installations in buildings & industrial plants. The Electrical Code covers rules in design process and the ways of installation. While the National Electrical Code (NEC) of the USA is sponsored by the National Fire Protection Association of America (NFPA), the PEC is published by the Institute of Integrated Electrical Engineers of the Philippines (IIEE).

Competent electrical practitioners are aware that fundamental rules and standards are needed to ensure safety to persons and properties from the hazards arising from the use, misuse, abuse & misapplication of electricity. That is the intent of any Electrical Code, the IEEE Recommended Practices and the IEC Design Guide, among other publications. Conforming to these rules or standards along with proper maintenance will result to electrical systems relatively free from hazards.

Although the aforementioned references include provisions for permissible methods of installation, as any electrical code says, they are not intended as a design or construction manual to untrained persons. Experts say that sound engineering practice, quality workmanship and good sense of economics along with flexibility, reliability and provisions for future growth are equally important considerations.

Again note that the flaws & defects” constituting faulty electrical wirings are electrical installations that are not of standard. As construction defects are not always easy to identify, there are numerous things that can go wrong in a building, amongst them maybe the results of soil settling or just the expected wear & tear. In the case of electrically started fires, the culprit could be faulty wiring. That’s why in the USA, electrical inspectors are not just appointed - they are certified as inspectors. They’ve got to pass the training, tests and certification process by the National Fire Protection Association (NFPA).


---------------------------------------------------------













(Do you want these installations in your own home or building?)



------------------------------------------

Integrity of Design & Construction

It should be noted that safety in homes and buildings begins at the drawing boards & design sheets. As pointed out earlier, a faulty electrical wiring could start from a faulty design. Thus the engineer must see to it that his design not only makes sense but of standards. But it must be emphasized that a design (in terms of Code Rules & International Standards) might be perfect on paper but could be horrible in the way the design is implemented.

Implementation is another field of expertise and the Code attempts to include some in its provisions. Therefore, in designing and its subsequent interpretation into reality, it is not of the business to just any person (‘do-it-yourselfers’, ‘cemetery electricians’ or the ‘street disco electricians’) – it must be a work of experienced professional engineers & registered master electricians who understand the responsibility of providing mankind with safe environment in the whole lifetime of a building or industrial plant.

Safety of life and preservation of property are two of the most important factors in the design of the electric system. Conforming to established codes & standards in the selection of the material and equipment is imperative. Professional & workmanlike installations are equally important because no matter how perfect the designs on paper are, it becomes useless when not implemented professionally. Most electrical disasters are caused by either poor design or due to the ignorance of correct installation practices.

To recall, a system might work out operationally as intended to but the same system might be violations of the Code. In situation like this, the Code being devoted to safety must never be compromised because electrical disasters don’t happen in just a few years from the first energization. Like a thief in the night, it usually happens when every one is not expecting.

And faulty wiring is not something an ordinary person should ever to try to fix. It needs professionals to correct it!

Thus, a safe, good and reliable building electrical wiring is a product of both design and execution of the plans into reality that are of standards. Not even value engineering can shatter the intent of the Code & Standards.


7.0) SUBSTANDARD DEVICES & MATERIALS

More often than not, too much cheap engineering is in fact, costly. By making the first cost not objectionable, it does not mean that the engineer shall use cheap, undersized and substandard materials or equipment. Applying correct Value Engineering, the design must fundamentally conform to good engineering practice, codes and standards. This fundamental requisite must not be compromised under the “cloak of costs”. Again, isn’t it that minimum standards must still stand-out even after any “value engineering” is applied..?












(Pictures of Substandard Installations Resulting to Fires)
------------------------------------------------------------


Reliability starts with the design engineer’s good sense of selection of electrical equipments & components that would soon compose a continuously operating system. It needs deep knowledge of the various electrical products available and good experience on the performance of these products.

Now note that aside from the National Building Code (c/o OBO) and the Fire Code of the Philippines (c/o BFP), the Bureau of Product Standards (BPS) is another standard-safeguarding agency overseeing the integrity of electrical devices, wires, apparatuses and equipment. But then, without a competent electrical practitioner around specifying and approving wiring devices (for a house or building under construction) may pose huge problems later on.

The Incandescent Lamp Socket

For instance, the incandescent bulb receptacles proliferating in shopping malls nowadays are of cheap “sardine-tin-like” (lata ng sardinas) socket material – too hot even to touch. If operated continuously non-stop for days, it becomes hot enough to melt the insulation at the terminals of conductors.

The Fluorescent Lamp Ballast

And the ballast cores - “sardine-tin-like” too. And if these ballasts burned, the house becomes a candidate for burning, too. Unlike the UL listed & other internationally renowned ballasts, these cheap ones don’t contain fire retardant elements.

The Adapters

In the past, if there were adapters, they were Mogul to E-27based sockets. Now, you can find E-27–to-Mogul adapters in shopping malls. Imagine the overheating that can result if we connect the sardine-tin-like socket of an ordinary E-27 base to mogul adapters to light up a 400w mercury or metal halide lamp? The overheating would not even trip the circuit because the circuit may not yet in over-loaded condition but the sardine-tin socket has already melted!

Studies of electrical fires in homes in the USA show that many problems are associated with improper use of electrical devices by do-it-yourselfers. Common practices that can lead to fires include the use of improperly rated devices such as switches or receptacles and loose connections at these devices. Both can lead to overheating and arcing that can start fires.


8.0: ABUSE & MISUSE OF ELECTRICITY

-------------------------------------------------------------------------

Sidebar:

Arcing by the way could be series or parallel. The parallel arcing is actually a short circuit or a ground fault while a series arcing is like a loosely connected switch (in this case, not a short circuit).

Have you experienced lighting a cigarette using the line series to a lamp through the wet tip of the cigarette? The wet tip of the cigarette acts as a switch that provides a loose path of current to the lamp. The current passing through the wet tip heats up – then finally igniting the cigarette.

Or a sausage heated for lunch by the same way as in the picture? The sausage when over-cooked becomes carbonized. Once carbonized, it ignites a fire.


-----------------------------------------------------------------------------


Of course, abuse & misuse of electricity certainly contribute to electrically started fires. Abuse & misuse of electricity is a given fact in a society populated by the common tao, who are yet to be guided on the safe use of electricity.

But let me ask these questions:

For instance, in the much ballyhooed “octopus wiring”, how can it ignite a fire when the circuit is protected by a circuit breaker..?

Overloading? If the circuit happens to be overloaded, isn’t it that the over-current protective circuit breaker trips off? That of course granting that the circuit breaker is correctly sized viz-a-viz the conductors.

“But the circuit breaker did not trip? Aha! The circuit breaker must have been oversized! There you are again - the oversizing made it faulty”.















But then in reality, there are normally a number of outlets in the same circuit with no loads or not in use at any given time. Chances are, the loads in the octopus connections may not reach the tripping threshold of the circuit breaker and thus, no breaker trips because there was no overload – as far as the circuit is concerned.

The danger actually lies at the point of connection, where the multiple outlets are tapped. For instance, an E27 base lamp socket is fitted with a screw base outlet which in turn multiple outlets are connected into it, the overload or overheating happens not in the circuit but in the socket itself. The same is true if the octopus wiring is derived from a wall outlet of low capacity. That for sure is a recipe for electrically-started fires.

Fires are also caused by people using the wrong size fuse or even putting a coin (in case of the glass fuse) behind a fuse when they don't have a spare.

As electricity and water are a bad combination, there are several cases that indoor type devices are installed outdoors.

But then, isn’t it that abuse or misuse of electricity will result to “faulty electrical wiring”?


(To be continued…)

Next Episode: THE FEEDERS & SUBFEEDERS

1 comment:

magi said...

I have seen your Blog... It’s too informative. There are many posts which are really too Good and very useful.
Thanks a lot for great work.
Electrical Wiring