In today’s industrial and commercial environments, uninterrupted power is not a luxury—it’s a lifeline. Whether it’s a manufacturing plant, hospital, or data center, a small electrical failure can lead to hours of downtime, production loss, and expensive repairs.
Two key components that determine the reliability of your power system are your Transformer and Vacuum Circuit Breaker (VCB). Both are critical for stable voltage supply and system protection. But here’s the truth—most breakdowns or failures don’t come from poor equipment quality. They come from installation and commissioning mistakes.
At Ashish Electrical, a Government Approved & ISO Certified Electrical Contractor in Surat, we’ve seen it all—loose terminations that caused transformer fires, VCBs tripping unexpectedly because of incorrect settings, and power shutdowns that could have been easily prevented.
In this blog, we’ll share the 7 most common mistakes industries make during transformer and VCB installation—and how you can avoid them.
1. Ignoring Proper Site Preparation & Foundation
Before a single bolt is tightened, the foundation decides whether your transformer or VCB will have a long and stable life.
Common errors include:
- Uneven or weak plinth foundation
- Lack of vibration pads or proper leveling
- Inadequate cable trench planning
- Poor earthing electrode layout around the foundation
A transformer placed on an uneven surface faces mechanical stress, which can lead to oil leaks, bushing cracks, and even internal winding damage.
At Ashish Electrical, our team follows precise civil foundation and earthing layouts as per the manufacturer’s drawings and IS/IEC standards to ensure stability, drainage, and electrical safety from day one.
2. Poor Earthing & Bonding
Transformer and VCB installations live or die by their earthing system. Faulty or inadequate earthing causes dangerous touch voltages, equipment damage, and relay malfunction.
Typical mistakes we find:
- Shared earthing between power and control systems
- High resistance due to corroded or undersized earth electrodes
- Incomplete bonding of metallic parts and panels
- Earthing not tested before energization
A dedicated, low-resistance earthing network ensures that fault current safely returns to the ground, protecting both the equipment and personnel.
Pro Tip: Always carry out megger testing and record resistance readings before commissioning.
Ashish Electrical performs earthing pit design, installation, and testing using calibrated meters and provides a full compliance report as part of the commissioning documentation.
3. Incorrect Cable Termination & Lugs
Cable terminations might look simple, but this is one of the biggest sources of heat build-up and fire hazards in electrical panels and transformers.
Common errors:
- Wrong lug size or crimping technique
- No use of gland plates or improper insulation
- Mixing aluminum and copper lugs without bimetallic washers
- Loose bolted connections leading to arcing
We often see failures traced back to a single loose connection that overheated under load.
At Ashish Electrical, our technicians follow manufacturer torque guidelines, use IS-approved compression tools, and perform thermal imaging tests post-installation to ensure every joint is sound.
4. Neglecting Protection Coordination & Relay Settings
Even if your transformer and VCB are installed perfectly, incorrect protection settings can cause nuisance tripping or worse—failure to trip during a fault.
Typical problems include:
- Relay curves not matched with upstream/downstream devices
- Wrong CT/PT ratios configured in relays
- Improper time delay coordination
- No secondary injection testing before energization
Proper protection coordination ensures your VCB trips selectively, isolating only the faulted section instead of shutting down your whole plant.
Ashish Electrical’s engineers perform relay testing and coordination studies to align settings with your single-line diagram (SLD), transformer size, and system short-circuit level—ensuring your protection works exactly as designed.
5. Skipping Routine Testing & Pre-Commissioning Checks
Many installations go live without comprehensive testing—a recipe for hidden faults and early breakdowns.
Essential tests that are often skipped:
- Transformer insulation resistance (IR) test
- Oil BDV (Breakdown Voltage) and moisture content check
- VCB contact resistance and vacuum integrity tests
- Control wiring and interlock simulation
- Functional trip tests
Ashish Electrical carries out a full pre-commissioning protocol including insulation, ratio, and polarity tests on transformers and all VCB operational tests before energization. Every reading is logged and submitted to the client and inspector for recordkeeping.
6. Poor Ventilation & Overheating Issues
Transformers and VCB panels generate heat, and lack of ventilation can cause overheating and premature failure of insulation, oil, and components.
We’ve seen installations where:
- Transformers were placed in cramped rooms with no airflow
- Dust accumulation blocked radiator fins
- Cooling fans were not wired to operate automatically
- VCB panels were stacked too close, trapping heat
Every 10°C rise above rated temperature can cut insulation life by up to 50%.
Ashish Electrical designs proper air circulation paths, louvers, and temperature monitoring systems—and where needed, installs automatic exhaust fans or BMS-linked temperature alarms to prevent overheating.
7. No Preventive Maintenance or AMC Plan
Even the best-installed transformer and VCB need regular preventive maintenance. Without it, minor issues—like oil leakage, worn contacts, or loose terminations—grow into major shutdowns.
Common oversights:
- No scheduled IR or contact resistance testing
- Transformer oil not filtered or tested periodically
- Dust, rodents, or moisture inside VCB panels
- Trip relays or interlocks not tested during shutdowns
Ashish Electrical offers comprehensive AMC (Annual Maintenance Contract) and ARC (Annual Repair Contract) packages that include:
- Scheduled testing of transformers and VCBs
- Thermography & insulation checks
- Cleaning, lubrication, and relay calibration
- Breakdown response support within committed timelines
With proper maintenance, many of our clients have extended transformer life by 10+ years and achieved zero unplanned shutdowns.
Key Takeaways
| Mistake | Result | Solution |
| Weak foundation | Vibration & oil leakage | Proper plinth & drainage design |
| Poor earthing | Shock hazard & relay malfunction | Dedicated earthing with low resistance |
| Loose cable termination | Overheating & fire | Correct lugs, torque, thermal scan |
| Wrong relay settings | Tripping or no trip | Protection coordination & testing |
| Skipped testing | Hidden faults | Pre-commissioning checklists |
| No ventilation | Overheating | Airflow & temperature control |
| No maintenance | Downtime & failure | AMC/ARC preventive schedule |
Why Choose Ashish Electrical?
- Government Approved & ISO Certified Contractor based in Surat, Gujarat
- Expertise in Transformer, VCB, HT/LT Panel, Cable Laying, Switchyard up to 66kV, Fire Safety & BMS Systems
- Proven track record in industrial, commercial, hospital, and infrastructure projects
- Complete solutions – from design and installation to testing, commissioning, and AMC support
- Team of experienced engineers ensuring every job meets IS/IEC standards and electrical inspector approvals
Conclusion
Downtime is expensive—but preventable. Most electrical breakdowns stem from avoidable mistakes during transformer and VCB installation.
With the right planning, testing, and maintenance, you can achieve years of reliable operation and protect your investment.
If you’re planning a new transformer or VCB installation, or want to audit your existing setup, Ashish Electrical can help.
📞 Call: +91-261-4611867
📧 Email: office.surat@ashishelectrical.com
🌐 Website: www.ashishelectrical.com
Let’s make your power system reliable, safe, and compliant—because with Ashish Electrical, downtime is not an option.