Energy Monitoring and Management, Power Quality

Managing Power Quality in Factories: Essential FAQs for O&M Teams

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Managing Power Quality in Factories: Essential FAQs for O&M Teams

During a recent technical discussion with an MSME user in western Uttar Pradesh- the Maintenance Head, Plant General Manager, Purchase Manager, and a group of maintenance engineers had gathered in the meeting room. The agenda was simple but critical: an exploratory engagement around the management’s growing concerns about OEE (Overall Equipment Effectiveness).

What started as a structured dialogue soon turned into an open, interactive session. The maintenance team, representing the client side, led the discussion with refreshing honesty about their challenges. Alongside them, a few younger mechanical and electrical engineers — eager to learn — began asking questions that many in the industry often hesitate to raise.

The conversation naturally drifted toward managing power quality in factories and the basic power quality issues — harmonics, low power factor, voltage dips, imbalances, and fluctuations. What followed was a lively Q&A session, with the client’s team raising practical questions and us sharing technical insights. It turned out to be a session that was not only valuable for the client but also equally enriching for us.

This article captures those questions in an FAQ format — so that other operations and maintenance professionals facing similar challenges can benefit from the exchange.

Q1. Our drives keep failing every few months. Someone said it could be “harmonics.” What exactly are they?

Yes, that’s a very common pain point. Harmonics are like unwanted “noise” in your electrical system, generated mostly by nonlinear loads — VFDs, UPS, welding machines, etc.

  • They distort the waveform of voltage and current.
  • This overheats cables, transformers, and motors, reducing equipment life.
  • Drives and control circuits suffer random trips, cutting into availability.

How to manage?

  • Conduct a harmonic survey.
  • Use passive or active harmonic filters.
  • Ensure equipment is sized to handle the expected distortion.

Impact on OEE: Mostly availability losses (tripping, downtime).

Q2. My EB bill shows “penalty for low PF.” But isn’t PF only about billing, not my machines?

That’s half true. Low power factor doesn’t just hurt billing — it wastes capacity.

  • Transformers and cables carry more current than necessary.
  • Voltage drops worsen, especially during motor starting.
  • Generators are overloaded with reactive power.

Fixes:

  • Install capacitor banks or automatic PF correction systems.
  • Consider SVG/ASVG for dynamic loads.

Impact on OEE: Low PF affects both performance (higher losses, less productivity) and availability (capacity bottlenecks).

Q3. We see uneven load sharing across phases. Sometimes one phase trips. What’s happening?

That’s unbalanced load — when different phases carry different currents.

  • Causes voltage unbalance.
  • Motors run hotter and may de-rate.
  • In severe cases, they trip on overload or thermal faults.

Solutions:

  • Balance distribution of single-phase loads.
  • Use load balancing relays or active compensation.

Impact on OEE: Reduced performance (machines run at lower efficiency) and sometimes availability (unexpected stoppages).

Q4. Our centrifuge and rotary drum dryer often trip during supply disturbances. Is that voltage dip?

Exactly. Voltage dips are sudden short-term drops in supply, usually caused by motor starting or grid faults.

  • Drives, PLCs, and sensitive machines trip instantly.
  • Production halts until maintenance restarts the equipment.

Mitigation:

  • Dynamic Voltage Restorers (DVR).
  • Static Var Generators (SVG/ASVG) for fast compensation.
  • Ensuring machines have ride-through capacity.

Impact on OEE: Big availability loss — stoppages, restarts, and missed production targets.

Q5. Then what’s the difference between a dip and a fluctuation?

Good distinction.

  • Dips = sudden, short-term collapse → immediate trips.
  • Fluctuations = slower, ongoing swings → machines don’t always trip, but run poorly.

Effect of fluctuations:

  • Motors overheat, efficiency drops.
  • Fans, blowers, heaters give inconsistent outputs.
  • Flicker visible in lighting.

Mitigation:

  • Servo stabilizers.
  • Tap-changing transformers.
  • Digital voltage regulators.

Impact on OEE: Mostly performance loss — production continues, but at lower efficiency and higher wear.

Q6. Sometimes our incoming supply is just too high or too low for hours. Is that another category?

Yes, that’s overvoltage and undervoltage — a long-term supply problem.

  • Sustained overvoltage burns insulation, lamps, and electronics.
  • Sustained undervoltage weakens motor torque, causing overheating.

Solutions:

  • Automatic Voltage Regulators (AVR).
  • Servo stabilizers.
  • DG sets with good control systems.

Impact on OEE: Gradual performance & quality loss, and eventually availability issues as machines fail early.

Advice from the Technical Manager

“Power quality isn’t just an EB billing issue. It’s directly tied to OEE — Availability, Performance, and Quality. If ignored, you’re losing production hours, machine health, and energy efficiency.

The first step? Awareness. The second? Right technology adoption. MSMEs can’t afford blind spots here.”

If you’re part of a maintenance, purchase, or plant management team and are looking to:

  • Understand how power quality links with OEE losses,
  • Identify hidden risks before they become costly breakdowns,
  • Or explore practical, ROI-driven solutions for your factory,

👉 We’d be glad to share similar insights and case stories with you. Please feel free to connect us:

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