Voltage fluctuation damage in factories must be documented before the evidence disappears. Low voltage, surges and phase imbalance can hurt motors, drives, control cards and production quality, but internal wiring faults can create similar symptoms. Measure first, repair safely, and keep records.
In many Indian plants, voltage complaints become emotional because equipment failure is costly and production is delayed. The owner calls the DISCOM, the electrician blames supply, the vendor blames the panel, and accounts waits for a bill. A better process starts with evidence.
What voltage symptoms should owners take seriously?
Voltage problems show up in both equipment and production. Some symptoms are dramatic, such as burnt drives. Others are small but repeated, such as contactor chatter or motor heating.
Watch for:
- Motors running hot or failing early.
- Drives tripping on under-voltage or over-voltage.
- Contactors chattering.
- Lights flickering during machine starts.
- Electronics resetting.
- Uneven three-phase currents.
- Production quality changing during certain supply periods.
One symptom alone does not identify the cause. It tells you where to measure.
What can low voltage do to motors?
Low voltage can make motors draw higher current for the required work, depending on load and condition. Higher current can mean more heat. If the motor is already overloaded, poorly cooled or imbalanced, damage risk increases.
Three-phase imbalance is especially important. A small-looking voltage imbalance can create unequal currents. This can heat one phase more than others and reduce motor life.
Motor complaints should include:
| Evidence | Why it helps |
|---|---|
| Current on each phase | Shows imbalance and loading |
| Voltage at motor terminals | Separates supply from cable drop |
| Motor temperature notes | Links symptom to operation |
For connection basics, single phase vs three phase factory load gives useful background.
How can internal faults look like supply problems?
Internal issues can mimic DISCOM voltage trouble. Loose lugs, undersized cables, overloaded panels, poor neutral condition and long cable runs can create voltage drop inside the premises. The incomer may be acceptable while a far machine suffers.
Check both ends:
- Voltage at the main incomer.
- Voltage at the affected panel.
- Voltage at the machine during operation.
- Phase currents and neutral condition.
- Thermal signs at joints and breakers.
This protects the owner. If the problem is internal, it can be fixed faster. If it is external, the complaint becomes stronger because internal causes were checked.
What evidence should be kept for DISCOM complaints?
DISCOM complaints need dated, clear evidence. A phone call without records rarely carries weight. Keep complaint numbers, screenshots, photos, logs and repair documents.
Useful evidence includes:
- Date and time of event.
- Equipment affected.
- Voltage readings or logger report.
- Photos of panel indications or damaged parts.
- Vendor fault report where available.
- Production stoppage notes.
- Complaint acknowledgement from the DISCOM portal or office.
For the formal route, read DISCOM complaint process for bills. The same evidence discipline helps technical voltage complaints.
Where do harmonics fit into voltage complaints?
Some complaints blamed on fluctuation may involve harmonics or other power quality issues. Drives, UPS systems, furnaces and APFC panels can create distortion or interact badly with the electrical system.
If trips happen only when certain equipment runs, do not stop at incoming voltage. Measure distortion, current and events. The article on harmonics and power quality complaints explains how to separate these issues.
Also check protection settings. A drive may trip because its threshold is tight or because supply is genuinely poor. The answer comes from event logs and measurements.
Tips from the field
- Measure voltage at both the incomer and the affected machine during the complaint condition.
- Keep photos of fault codes and panel indications before resetting equipment.
- Record DISCOM complaint numbers because informal calls are hard to prove later.
- Check terminal tightness and thermal hot spots before blaming external supply.
- Use a logger when events are intermittent because manual readings may miss the dip or surge.
- Preserve failed parts until the vendor or insurer has inspected them where a claim may arise.
How should a factory protect itself?
Protection starts with good internal electrical health: correct cable sizing, tight joints, proper earthing, suitable protection, load balancing and maintenance. Then add surge protection, voltage relays, stabilisation or UPS only where the equipment need justifies it.
Do not buy protection devices blindly across the whole plant. Critical machines, drives, electronics and process controls deserve priority. A measured power quality audit gives the owner a defensible plan, and it also stops repeated arguments after every failure.