Shahnawaz Hussain l Gabriel Technical Academy

Shahnawaz Hussain l Gabriel Technical Academy Let's grow your career in Electrical Engineering | Global Technical Support Specialist - Electrical What problems do you currently have with your resume?

As a professional resume writer, I specialize in transforming "" resumes into exciting and powerful marketing tools! If you feel like:
✓ Your resume doesn't adequately represent you...
✓ You don't have the confidence to apply for your dream role...
✓ You don't know what your strengths are, let alone how to communicate them...
✓ You can TALK about what you've done but not WRITE it…
✓ Your resume do

esn't make it to the hiring manager's table, even though you have all the skills they need…

You're in the right place, and I can help you! Having a resume you’re proud of sharing with recruiters is an important tool in the job hunt process. And it pays for itself -- by shortening the job search cycle, by improving your interviews with recruiters, and by instilling confidence in you. Here's how the resume overhaul process works with me:
- You tell me your target job title and share your existing career documents with me.
- We schedule a call where I dig deep to uncover your unique strengths.
- And that's it! You have a new resume that truly reflects what you've accomplished and the value you bring to the table within 7 business days! I also work on LinkedIn profiles and cover letters. If you feel like you need those to accompany your resume and create a consistent brand, I can deliver. Please visit my website to see my services: gabrielengineering.org

Please email your resume to me at: [email protected]

Want to know what others have to say about my service? Scroll down to my recommendations. :)

Thank you. CVExperts | WhatsApp: +91 87399 22125

23/08/2026

The most valuable professionals aren't the ones who work the longest hours.

They're the ones who solve the most expensive problems in the shortest time.

When a generator fails, a production line stops, or a critical electrical system goes offline, every minute costs money. Clients aren't paying for someone to "look busy." They're paying for someone who can quickly identify the root cause, make the right decision, and restore operations safely.

That's why I invest in learning every day—electrical systems, industrial automation, troubleshooting, AI, and new technologies.

Knowledge compounds.
The more you know, the faster you solve problems. The faster you solve problems, the more time and money you save. The more value you create, the more opportunities come your way.

Don't chase hours.
Build skills that make every hour count.
Your income is rarely determined by how hard you work. It's determined by how expensive a problem you can solve.

What's the most expensive problem you've solved in your career?

23/08/2026

A Project rarely falls behind because of one major event.

More often, delays are built quietly through small unresolved issues:

• A drawing waiting for approval.
• A material submittal without a clear decision.
• A workfront released before all interfaces are coordinated.
• A long-lead item identified too late.
• A technical issue discussed repeatedly but never formally closed.

Individually, each issue may look manageable.

Collectively, they become the critical path.

This is why effective project management is not only about tracking progress percentages. It is about maintaining decision flow, workfront readiness, and interface closure before they start affecting site productivity.

On construction projects, I believe one of the most important questions in every progress meeting should be:

“What can stop us in the next 2–4 weeks?”

Not only:

“What did we complete last week?”

Strong project control is proactive, not historical.

The earlier we identify constraints, assign ownership, and close them, the more control we retain over time, cost, and delivery.

23/08/2026

⚡ Transformer Routine Testing — Part 2/5

🔄 Transformer Turns Ratio (TTR)

A TTR test is often explained as:
“Check whether the turns ratio is correct.”

That’s true but there is quite a bit more information hiding in the result.
For TTR testing, I used the Raytech TR-MARK III 250V.

Most of my tests were performed at:
⚡ 100 V AC

The instrument also allows 1, 10, 40 and 250 V AC, with a maximum test current of 1A.

For every phase and tap, I mainly watched:

• Turns Ratio
• Deviation [%]
• Excitation Current [mA]
• Phase Displacement [°]

For our FAT testing, the measured ratio on each phase/tap had to remain within ±0.5% of the calculated ratio.

🔢 Why does the ratio change with tap position?

The nameplate data gives us the winding voltages and number of turns at each tap.

Changing the HV tap changes the number of active turns so naturally, the expected ratio changes with it.

Turns Ratio = HV Turns / LV Turns

But there is another interesting point.

The Raytech can display both TURN RATIO and VOLTAGE RATIO, and these numbers are not always the same.

Take a 22 kV / 433 V Dyn transformer:
Line voltage ratio:
22,000 / 433 ≈ 50.8

But because the LV winding is star connected:
LV phase voltage = 433 / √3 ≈ 250 V
So the winding turns ratio becomes:
22,000 / 250 ≈ 88

Both values are correct — they are simply looking at the same transformer from different electrical reference points.

🔍 Phase connections can tell another story.

If A and C are accidentally swapped on the LV side, the three ratio readings will no longer follow the expected pattern.

Depending on the vector group, two readings may appear similar while another is completely different.

That makes TTR a very quick way of finding incorrect phase connections.

⚙️ I also always keep an eye on excitation current.

If one phase or tap shows an unusual:
• Excitation current
• Ratio deviation
• Phase result
…it is usually time to start investigating.

I would check things like:
→ Tap-selector contacts
→ Leads and crimps
→ Phase connections
→ Internal wiring

If the result looked suspicious, one quick check was to manually cycle the tap selector:
Tap 1 → Tap 7 → Tap 1
a few times and repeat the test.

Sometimes that was enough to re-seat the selector contacts. If the abnormal result remained, then it was time for an internal inspection.

I have carried out TTR testing across:

🔹 Single-phase transformers
🔹 Three-phase transformers
🔹 Different vector groups
🔹 SWER transformers
🔹 ZN / earthing transformers

So for me, TTR was never simply:
❌ “Ratio is correct = PASS.”

The real value is checking whether the turns, tap position, excitation current, phase relationship and actual winding connections all make electrical sense together.

23/08/2026

⚡ Transformer Routine Testing — Part 1/5

Insulation Resistance (Megger)

I’m starting a short series on routine transformer testing — not just what each test is called, but what is actually happening electrically, what I look for in the results, and what those numbers can tell us when something isn’t right.

During my time in transformer testing, I carried out routine, type and special tests on oil-filled transformers ranging from 25 kVA up to 5000 kVA, including 11 kV/433 V, 22 kV/415 V and 33 kV/480 V units.

Let’s start with one of the first checks:

Insulation Resistance

For this test, I normally applied:
⚡ 2.5 kV DC
⏱️ 60 seconds

And checked three insulation paths:
• HV → Earth
• LV → Earth
• HV → LV

All terminals of the winding under test were shorted together. For a star-connected LV winding, the neutral was included as well.

🛡️ One part of this test that doesn’t get discussed much is the GUARD terminal.

→ HV to Earth: LV connected to GUARD
→ LV to Earth: HV connected to GUARD
→ HV to LV: transformer tank connected to GUARD

Why?
Because we want to exclude unwanted parallel leakage paths and measure the insulation path we are actually interested in.

⚙️ Electrically, the Megger is doing something quite simple:
DC Voltage → Very Small Current → Resistance
R = V / I

With healthy transformer insulation, the measured current can be down in the microamp range or even into nanoamps, which is why the resistance can easily reach GΩ.

But this is where it gets more interesting.

When 2.5 kV DC is first applied, the current is not purely leakage current.
Initially, we also have:

🔹 Capacitive charging current
🔹 Dielectric absorption / polarization current
🔹 Leakage / conduction current

The charging and absorption components reduce with time.
That is one reason why the defined 60-second reading is more meaningful than simply looking at the first number that appears after pressing TEST.

📈 On new transformers, we normally expected the results to be comfortably in the GΩ range and depends upon Transformer construction, temperature, insulation condition, contamination and measurement configuration.

⚡ Small test-bay fact:
We may be applying 2.5 kV, while healthy insulation is only passing micro or nanoamps. If someone accidentally becomes part of the circuit, the current can rise rapidly towards the tester’s current limit and the unit may cut out at 3mA.

Still… definitely not something I’d recommend testing personally. 😄⚡

The real engineering is understanding:

• What current are we actually measuring?
• Which insulation path are we testing?
• Why does the resistance change with time?
• And does the result make sense for that transformer and test configuration?

23/08/2026

📌 Tan Delta Test

☑ Tan δ test evaluates dielectric losses in insulation. Non-destructive diagnostic test to assess insulation quality. Detects deterioration, moisture or contamination before failure.

☑ Tan δ = Dissipation Factor or Power Factor. Represents phase difference between current and voltage in insulation. Indicates how much energy is lost as heat inside dielectric material.
Low Tan δ → Healthy insulation.
High Tan δ → Moisture or aging

☑ AC voltage applied across insulation.
Leakage current has two components:
Capacitive Current (Ic) – Ideal dielectric
Resistive Current (Ir) – Due to losses
Tan δ = Ir / Ic

☑ It can will leads to below negative impacts:

✔Reduced efficiency:
The dielectric loss is a measure of the energy that is lost due to the resistance of the insulation material. If the Tan Delta value is high, it means that the insulation is less effective in preventing energy losses. This can result in reduced efficiency of the Equipment.
✔Overheating:
Dielectric loss generates heat in the insulation, which can cause the equipment to overheat. If the Tan Delta value is high, the insulation will generate more heat, which can lead to thermal degradation and reduce the lifespan of the transformer.
✔Reduced lifespan:
Over time, high dielectric losses can lead to accelerated degradation of the insulation, which can reduce the lifespan of the equipment.
✔Safety risks:
A high Tan Delta value can indicate that the insulation is weakening and may be at risk of failing, which can cause safety risks such as electrical shorts, fires, or explosions.

☑The “Insulation Resistance” test is designed to measure the resistance of insulation by applying a low-voltage DC signal and measuring the resulting current. It helps detect any leakage paths or deterioration in insulation, making it a useful tool for routine maintenance and inspections.

☑“Tan Delta” values indicate insulation degradation due to factors like aging, moisture, or contamination. Assesses the overall quality and health of insulation.

23/08/2026

✅Relay Testing (MiCOM P122 & P127)

The protection relays tested using the OMICRON CMC 356 test equipment.

The following protection functions were tested:

➡️ Overcurrent Protection (50/51)
Instantaneous and inverse time overcurrent characteristics were verified. Pickup values, time delays, and curve characteristics were checked in accordance with IEC requirements.

➡️ Earth Fault Protection (50N/51N or 50G/51G)
Residual current-based earth fault protection was tested for correct pickup and tripping performance.

➡️ Directional Overcurrent Protection (67)
Directional elements were verified by applying appropriate voltage and current phase angles to confirm correct forward and reverse operation.

➡️ Directional Earth Fault Protection (67N/67G)
Directional earth fault functionality was tested using residual current and voltage injection to ensure proper directional sensitivity.

➡️ Residual Voltage Protection (59N / 64G depending on configuration)
Residual voltage (neutral displacement) protection was tested to confirm pickup settings and operation under unbalanced voltage conditions.

➡️ Overvoltage Protection (59)
Relay response to voltage above the set threshold was verified, including pickup accuracy and time delay.

➡️ Undervoltage Protection (27)
Relay performance under low voltage conditions was tested to ensure correct operation and timing.

23/08/2026

▶️ Transformer Differential Protection

✅Purpose: Transformer differential protection protects the transformer against internal faults.

Basic Principle: It compares the current entering the transformer with the current leaving the transformer.

✅Current Balance: Under normal conditions and external faults the compensated differential currents are approximately equal, so the relay does not trip.

✅Internal Fault: During an internal fault, the currents become unbalanced and a differential current (operate current) flows through the relay.

✅Operating Principle:
Differential Current = |I₁ − I₂|
where I₁ and I₂ are the properly ratio- and phase-compensated currents from the two sides.

✅CTs: Current Transformers (CTs) are installed on different sides of the transformer to provide current signals to the differential relay.

✅CT Ratio Matching: CT ratios must be selected or compensated so that the relay can correctly compare currents from the HV and LV sides.

✅Vector Group Compensation: The transformer phase displacement, such as Dyn11, YNd1, must be compensated by the relay.

✅Percentage Bias/Restraint: Modern differential relays use a biased characteristic to prevent unwanted tripping during heavy external faults and CT saturation.

✅Two Important Quantities:
Operate/Differential Current (Id) Causes the relay to operate.
Restraint/Bias Current (Ib) Provides stability against unwanted operation.

✅Internal vs External Fault:
Internal fault → Differential current increases → Relay trips.
External fault → Through current increases, but differential current remains low → Relay remains stable.

✅Inrush Current: Transformer energization produces a high magnetizing inrush current, which can look like a differential current.
Inrush Restraint: To avoid unwanted tripping during energization, differential relays commonly use 2nd-harmonic restraint/blocking or advanced inrush detection.

✅CT Saturation: CT saturation during heavy external faults can create false differential current. The biased differential characteristic helps maintain stability.

✅Trip Command: When the differential current exceeds the relay's operating characteristic, the relay sends a trip command to the transformer circuit

Address

Kota
324006

Website

Alerts

Be the first to know and let us send you an email when Shahnawaz Hussain l Gabriel Technical Academy posts news and promotions. Your email address will not be used for any other purpose, and you can unsubscribe at any time.

Contact The Business

Send a message to Shahnawaz Hussain l Gabriel Technical Academy:

Shortcuts

Share

Category