Pagsasakatuparan at Pagsisimula ng 10kV Dry-Type Transformers

Ni James, may 10 taon na karanasan sa pag-aalamin ng mga kagamitang elektrikal

Kamusta lahat, ako si James, at nagsisilbing teknisyano sa pag-aayos ng mga kagamitang elektrikal na mayroong problema sa loob ng 10 taon.

Sa nakaraang dekada, nagtrabaho ako sa iba't ibang laki ng pabrika, substation, at distribution room, kasama ang pag-install, commissioning, maintenance, at troubleshooting ng mga dry-type transformers. Ang mga dry-type transformers ay isa sa mga pinakakaraniwang kagamitan na kinakahandahan namin araw-araw.

Ngayon, isang bagong kasamahan ang nagtanong sa akin:

“Kami ay kamakailan lang nang natanggap ng bagong dry-type transformer — paano ito i-install at icommission? Ano ang dapat kaming bantayan?”

Ito ay isang napakapaktol na tanong, lalo na para sa mga nagsisimula sa industriyang ito — parang isang "dapat malaman" na paksa para sa mga beginner. Kaya ipapaliwanag ko ang lahat ng detalye sa simpleng paraan, batay sa aking tunay na karanasan sa loob ng mga taon, upang mabigyan kayo ng malinaw na pag-unawa at tiwala sa inyong gawain.

1. Ano ang Dry-Type Transformer?

Simulan natin sa isang maikling pagpapakilala:
Ang dry-type transformer ay isang air-cooled, epoxy-resin insulated transformer, malawakang ginagamit sa mga opisina, ospital, mall, at data centers — mga lugar kung saan mahalaga ang fire safety.

Kunwari sa oil-immersed transformers, hindi ito gumagamit ng insulating oil, kaya mas ligtas at mas eco-friendly. Gayunpaman, mas sensitibo ito — lalo na sa humidity, ventilation conditions, at kalidad ng installation.

2. Ano ang Dapat I-prepare Bago ang Installation

Bago simulan ang installation, ang paghahanda ay mahalaga. Huwag magmadali — siguraduhin na malinaw ang sumusunod na puntos:

1. Unboxing Inspection

• Suriin kung buo ang packaging;

• Konfirmahin kung kompleto ang product certificate, manual, at factory test report;

• Tsek naman kung tama ang nameplate parameters (capacity, voltage ratio, wiring group) ay tugma sa design requirements;

• Suriin kung mayroong pisikal na pinsala, deformation, o rust;

• Siguraduhin na buo ang windings, busbars, fans, at temperature controllers.

2. Environmental Inspection

• Ang lugar ng installation ay dapat tuyo at may sapat na ventilation, iwasan ang direkta na sikat ng araw;

• Walang corrosive gases o flammable/explosive materials malapit;

• Ang floor ay dapat pantay at ang load-bearing capacity ay tugma sa requirements ng equipment;

• Ang humidity sa switch room ay dapat 60% o mas mababa upang iwasan ang insulation dampness;

• Kung posible, i-install ang dehumidifiers o space heaters.

3. Tools and Documentation

• Installation drawings, wiring diagrams, manufacturer technical manuals;

• Torque wrench, multimeter, megohmmeter, infrared thermometer;

• Ground resistance tester, insulating mat, personal protective equipment;

• Lifting tools (e.g., crane, hoist, lifting straps).

3. Key Steps During Installation

Narito ang isang standard na proseso ng installation na aking nalinyuhan sa loob ng mga taon:

Step 1: Positioning the Transformer

• Ilagay ang dry-type transformer sa pre-prepared foundation nito;

• Gumamit ng level upang masiguro na ito ay naka-align nang maayos;

• I-tighten ang mounting bolts at markahin ito para sa future inspection ng looseness.

Step 2: Primary and Secondary Side Wiring

• Ikonekta ang high at low-voltage cables ayon sa wiring diagram;

• Gumamit ng torque wrench upang i-tighten ang terminals ayon sa specifications;

• Masiguro ang tama na phase sequence upang iwasan ang reverse rotation o short circuits sa panahon ng power-up;

• Balutin ang exposed parts ng heat-shrink tubing o insulating tape;

• Gumamit ng multimeter upang suriin ang continuity pagkatapos ng wiring.

Step 3: Grounding System Installation

• Ang enclosure at core ng transformer ay dapat ma-reliably grounded;

• Gumamit ng copper grounding wire ≥50mm²;

• At least two grounding points connected to the main grounding grid;

• Test ground resistance ≤4Ω using a ground resistance tester.

Step 4: Temperature Controller and Fan Wiring

• Ilagay ang temperature probe sa designated hole at secure it;

• Pansinin ang fan motor phase sequence upang masiguro ang tama na airflow;

• Set alarm at trip temperatures (typically 130°C alarm, 150°C trip);

• Test fan start/stop function.

Step 5: Cleaning and Covering

• Linisin ang internal dust at debris;

• Double-check all fasteners are tightened;

• Close cabinet door, label with device number, capacity, and purpose.

4. Key Points During Commissioning

Hindi ang installation ang huli — ang tamang commissioning at testing ay mahalaga upang masiguro ang ligtas at reliable na operasyon.

1. Insulation Resistance Test

• Gumamit ng 2500V megohmmeter upang sukatin ang insulation sa pagitan ng windings at ground, at phase-to-phase;

• Low-voltage side insulation ≥100MΩ, high-voltage side ≥500MΩ;

• Kung mababa ang value, maaaring dahil sa moisture — dry at retest;

• Record R15 and R60 values, calculate absorption ratio (R60/R15 ≥1.3).

2. DC Resistance Test

• Sukatin ang DC resistance ng bawat winding;

• Detekta ang open circuits, shorts, o poor connections;

• Three-phase imbalance should not exceed ±2%.

3. Voltage Ratio Test

• Verify voltage ratio matches nameplate;

• Identify turn-to-turn short circuits or incorrect wiring;

• Tolerance within ±0.5%.

4. No-Load Test

• Keep low-voltage side open, apply rated voltage on high-voltage side;

• Measure no-load current and losses;

• Determine if there's core damage or local short circuit.

5. System Integration & Trial Run

• Power up temperature controller and fan control system;

• Observe normal fan startup/shutdown;

• Run under light load for at least 2 hours;

• Use infrared thermography to monitor connection temperatures;

• Ensure no abnormal heating, noise, or vibration.

5. Common Issues and Solutions

From my field experience, here are some common issues and how to handle them:

6. My Suggestions and Experience Summary

As someone with 10 years of electrical equipment repair experience, I always say:

“Installation is the first step, commissioning is critical, and maintenance ensures reliability.”

Dry-type transformers may look simple, but their performance directly affects the stability and safety of your power system.

So here are my suggestions:

Installation Tips:

Follow manufacturer instructions and technical standards strictly;

• Pay attention to details like torque, phase sequence, and grounding;

• Better to spend an extra 30 minutes checking than to face emergency repairs later.

Commissioning Tips:

• Don’t skip any test steps, especially insulation and ratio tests;

• Keep complete records for future analysis;

• Closely monitor during trial operation and address issues immediately.

Maintenance Tips:

• Regular cleaning, especially around windings and air vents;

• Check fans, temperature controllers, and terminal blocks;

• Monitor hotspots with infrared thermometers;

• Maintain equipment logs and track performance trends.

7. Final Thoughts

Installing and commissioning dry-type transformers may sound technical, but once you understand the basic steps and precautions, it becomes manageable.

Remember this key message:

“Details determine success or failure; safety comes first.”

If you're dealing with similar issues on-site and aren’t sure how to proceed, feel free to reach out — we can work through it together and find the best solution.

May every time you close the breaker bring a smooth “click” — not a sudden “bang!”

— James