Ang Kailangan Mong Malaman Tungkol sa Mga Pagkakamali ng Load Switch

Kamusta, ako si Blue — nagtatrabaho na bilang isang electrical engineer ng higit sa 20 taon ngayon.
Nag-umpisa ang karamihan ng aking karera sa pagdisenyo ng mga circuit breakers, pagmamanage ng mga transformers, at pagtulong sa mga power companies na lutasin ang iba't ibang hamon sa electrical system.

Ngayong araw, isang kaibigan mula sa Southeast Asia ang nagsabi sa akin:

"Ano ang mga karaniwang kapansanan ng load switch?"

Mahusay na tanong! Kaya, ipaliwanag natin ito sa simple terms — walang fancy jargon, tama lang ang totoong bagay na maaari mong makita sa trabaho o panahon ng maintenance.

Una, Ano Ba Talaga Ang Load Switch?

Bago nating talakayin ang mga problema, mabilis na i-recap natin kung ano ang load switch.

Ang load switch ay parang isang heavy-duty on/off switch na ginagamit sa medium-voltage systems (tulad ng 10kV, 20kV grids). Maaari itong gumawa at hiwalayin ang normal operating currents, ngunit hindi fault currents — iyon ang tungkulin ng circuit breakers.

Kaya, isipin mo ito bilang ang "middle guy" sa pagitan ng regular switch at ng full-blown circuit breaker. Mas simple, mas mura, at madalas ginagamit sa distribution networks, lalo na sa mga lugar kung saan ang protection coordination ay hindi sobrang komplikado.

Ngayon, Pag-usapan Natin Ang Mga Karaniwang Kapansanan

Sa aking mga taon ng fieldwork at troubleshooting, nakakita na ako ng paulit-ulit ang mga isyung ito. Narito ang listahan ng mga pinaka-karaniwan:

1. Failure to Close or Open Properly

Ang isa na ito ay napakakaraniwan, lalo na sa mga matandang equipment.

Sometimes ang switch ay hindi mag-closed kahit na pindutin mo ang button.

O nagsasara, pero agad na nagbubukas.

Puwede ring makuha sa closed position at ayaw magbukas.

Bakit ito nangyayari?

Ang mga mechanical parts ay nagiging worn out sa paglipas ng panahon — linkages jammed, springs weak, latches misaligned.

Ang control circuits ay maaaring may loose wires o burned relays.

Sometimes ang motor operator (kung electrically operated) ay nababago.

Real-life example:

I once worked on a site where the load switch wouldn’t close because a small screw had fallen into the mechanism and was jamming the movement. Took us 2 hours to find it!

2. Overheating or Burning Smell

Kung maamoy mo ang burning smell malapit sa load switch panel, huwag ito i-ignore.

Ang overheating ay kadalasang nangyayari sa contacts o terminal connections.

Maaring mag-lead sa insulation damage, melting parts, o kahit na fire kung hindi ito ma-ayos agad.

Causes:

Loose cable connections — mataas na resistance = heat.

Contacts getting old or pitted — bad contact surface.

Excessive current flow beyond rated capacity (overloading).

Tip: Always check the temperature regularly using infrared thermography. If a connection is more than 10–15°C hotter than others, investigate ASAP.

3. Arcing or Flashover During Operation

Maririnig mo ang loud pop, baka pa makita ang sparks — iyon ang arcing.

Nangyayari ito lalo na sa pagbubukas/pagsasara operations.

Mahigpit, maaaring mag-damage ng components o mag-cause ng injury.

Common reasons:

Main contacts worn out — gaps not maintained properly.

Dust or moisture inside the chamber — lowers insulation level.

Operating under load when it shouldn’t be (e.g., switching off a large motor without a circuit breaker upstream).

Note: Load switches are not meant to interrupt fault currents, only normal load currents. If you’re trying to cut through a short-circuit current, expect trouble.

4. Mechanical Wear and Tear

Ang load switches ay mechanical devices. Gumagalaw ang mga bahagi, kaya nag-wear out din sila sa huli.

Bearings, gears, and levers all degrade over time.

Lalo na totoo sa mga environment na may dust, salt spray, o extreme temperatures.

Prevention tip: Regular preventive maintenance (PM) is key. Lubricate moving parts, inspect linkages, and replace worn-out components before they fail.

5. Control Circuit Failures

The control side is just as important as the main circuit.

Indicator lights stop working.

Remote operation fails.

Local buttons don’t respond.

Typical causes:

Blown fuses in the control circuit.

Corroded terminals or broken wires.

PLC or RTU communication errors (in automated systems).

Quick fix idea: Use a multimeter to trace voltage drop and continuity. Start simple — check fuses first.

6. Moisture and Corrosion Inside the Enclosure

Especially common in coastal areas or humid climates.

Moisture gets into the switchgear cabinet.

Causes rust, corrosion, and reduced insulation levels.

Symptoms:

Tripping for no apparent reason.

Arcing even under light load.

Bad smell or condensation visible inside the box.

Solution: Make sure the enclosure has proper sealing and desiccant packs. In tropical areas, consider adding space heaters or dehumidifiers.

7. Wrong Operation by Personnel

Human error is still one of the biggest causes of failures.

Someone tries to open the switch under heavy load.

Or operates the switch without checking interlocks.

Even worse — someone forgets to lock out/tag out before maintenance.

Lesson learned: Training matters. Clear labeling helps. And always follow safety procedures.

Final Thoughts

Like any electrical equipment, load switches aren’t perfect. But with good design, regular maintenance, and proper operation, most of these faults can be avoided or caught early.

As someone who’s been in the field for over two decades, my advice is:

“Don’t wait for a failure to remind you that maintenance is important.”

If you're dealing with a faulty load switch and want help troubleshooting or choosing replacements, feel free to reach out. Happy to share more stories (and some war scars) from the field.

Stay safe, and keep the lights on!

— Blue