Voltage fluctuation in Nellore: which appliances need a stabiliser

Supply voltage in Nellore is not steady. Summer evenings, when every AC and cooler on the feeder is running, it sags; when a cut ends or a heavy load drops off, it jumps. Rural feeders at the edges of the district tend to swing more than the city centre. Indian supply is meant to be 230 V, and anything between roughly 207 and 253 V is within the normal band — but many localities here sit outside it for an hour or two every evening.

That is the background. The practical question is which of your appliances actually needs a stabiliser, and which just needs a spike guard or nothing at all.

Which appliances need one

Appliance	Stabiliser?	Why
Air conditioner	Yes	Compressor motor; low voltage makes it draw more current and run hot; a start during a dip can stall it. Get one with time delay.
Refrigerator	Usually	Same compressor logic. Many newer fridges state a wide operating range on the label — check before buying.
Washing machine (front-load)	Often	Motor plus control board. Check the rated range; if it is narrow, fit one.
TV, set-top box, router	No, spike guard	Wide-range power supplies; what kills them is a surge, not a sag.
Geyser, iron, kettle	No	Resistive heaters do not mind voltage; they just heat a little slower or faster.
Microwave, mixie	Rarely	Short runs; only if your voltage is badly off.
Computer	UPS, not stabiliser	A UPS carries it through a cut as well as a dip.
Water purifier (RO)	No	Small pump and adapter; a spike guard is enough.

Why the AC and fridge top the list

A compressor is a motor, and a motor at low voltage draws more current for the same work. Running like that through a three-hour evening sag, every evening from April to June, cooks the winding and shortens the compressor's life. The other risk is the restart: when power returns after a cut, voltage can spike and the compressor tries to start under full pressure. A stabiliser with a built-in time delay holds the AC off for a few minutes and starts it on clean voltage.

Inverter ACs have wider operating ranges than older fixed-speed units, but the people who fit them here still recommend a stabiliser where evening dips are regular. It is cheap insurance on the most expensive motor in the house.

Sizing one

Stabilisers are rated in kVA. Match it to the appliance: a 1-ton AC is generally paired with a 3 kVA unit, a 1.5-ton with 4 kVA, a 2-ton with 5 kVA, and a fridge or washing machine with a small 0.5–1 kVA model. Check the current on the appliance's rating plate and buy the next size up, never down. Look for the input range — a unit that only corrects from 170 V is less use than one that works from 140 V if your locality dips hard.

A whole-house (mainline) stabiliser at the distribution board is an option where the swing is severe. It is wiring work, sized for the home's connected load, and it protects everything at once.

Signs your voltage is a problem

• Fans slow and lights dim every evening, recover late at night.
• Lights flicker when the fridge or AC starts.
• Bulbs and LED drivers fail far more often than they should.
• The AC trips on its own protection, or the stabiliser (if you have one) clicks constantly.
• The inverter display shows mains below 200 V or above 250 V regularly — that display is the easiest voltmeter in most homes.

One pattern is an emergency: some lights suddenly very bright, others dim, bulbs popping, a burning smell. That is a loose or broken neutral, at your board or on the supply side. Switch off the main, unplug sensitive appliances, and get it looked at at once — it can destroy every electronic item in the house.

What you can do yourself

Plug-in stabilisers for the fridge, TV and washing machine are safe to fit: plug the stabiliser into the wall, the appliance into the stabiliser, and place it where it gets air, not behind the fridge against the wall. Use a spike-guard board for electronics. Do not daisy-chain stabilisers, and do not plug an AC into a stabiliser on an ordinary 6 A socket — the AC needs its own 16 A point.

Anything at the distribution board — a mainline stabiliser, a new AC point, tracing a loose neutral — is a technician's job.

When to call

If the whole house dims and flickers rather than one appliance, if you see the bright-and-dim pattern, if an AC or fridge is tripping in the evenings, or if you want a mainline stabiliser fitted. An Electrician Visit on our rate card is ₹350 plus labour; fitting a dedicated AC point for the stabiliser to feed is wiring work, listed at ₹699, with wire, MCB and socket at MRP and shown before fitting.