Question 1

What size generator do I need?

Accepted Answer

Add up the loads that run together (demand load), convert to kVA, then check that the largest motor can start on top of it. A healthy set runs at roughly 50 to 80 % of its rating for most of its hours.

Question 2

What is the difference between kVA and kW?

Accepted Answer

kW is the real power that does work; kVA is the total the alternator must carry. They are linked by power factor, and diesel sets are usually rated at 0.8 power factor, so 100 kVA corresponds to 80 kW.

Question 3

What is the full-load current of a 1,000 kVA DG set?

Accepted Answer

At 415 V three-phase, full-load current = kVA × 1,000 ÷ (1.732 × 415), which is about 1.39 A per kVA. A 1,000 kVA set carries about 1,391 A, a 1,010 kVA set about 1,405 A and a 250 kVA set about 348 A.

Question 4

How many kVA and kW is 1 MVA?

Accepted Answer

1 MVA is 1,000 kVA. At the standard 0.8 power factor of diesel sets, that is 800 kW of real power.

Question 5

Why does motor starting matter so much?

Accepted Answer

A motor started direct-on-line can draw five to seven times its running current for a second or two. If the set cannot absorb that step, the voltage dips, contactors drop out and other equipment resets.

Question 6

Should I choose a standby, prime or continuous rating?

Accepted Answer

Standby is for emergency use when the grid fails, prime is for unlimited hours at varying load, and continuous is for constant base load. Choose by how many hours a year the set will run and how steady the load is.

Question 7

Is a bigger generator always safer?

Accepted Answer

No. A set that runs at 10 to 20 % of its rating for long periods suffers wet stacking, bore glazing and carbon build-up. Correct sizing protects the engine as well as the load.

Question 8

Single-phase or three-phase?

Accepted Answer

Choose three-phase if the supply is three-phase or there is any three-phase motor such as a submersible, lift or compressor. Single-phase suits small homes and shops, usually up to about 15 kVA.

Question 9

Generator, inverter or UPS: which do I need?

Accepted Answer

A UPS gives a no-break supply for minutes, an inverter covers light loads for a few hours, and a generator covers heavy loads for as long as there is fuel. Many sites use a generator with a UPS for sensitive equipment.

Question 10

What size generator suits a house or villa?

Accepted Answer

Most independent houses and villas need 10 to 30 kVA, depending on air conditioners, the borewell pump and any lift. A load worksheet gives the right answer for your home.

Question 11

What should I check before buying a generator?

Accepted Answer

Confirm the sizing, rating type, emission and noise compliance, parts support for the engine family, alternator quality, controller features and what the quotation includes. Most expensive mistakes are made before the order is placed.

Question 12

Is a used generator a good buy?

Accepted Answer

It can be, if it has been properly inspected and tested under load. Every used and refurbished set we sell is load-bank tested before sale; refurbished sets carry a six-month warranty, and used (as-is) sets come with an inspection report.

Question 13

What is the difference between used and refurbished?

Accepted Answer

A used set is sold as it is, after inspection and testing. A refurbished set has been totally or partially rebuilt before sale and carries our six-month warranty, which excludes rubber and plastic parts, consumables, fuel damage and overload.

Question 14

What should a used-generator inspection cover?

Accepted Answer

Starting from cold, smoke and noise under load, oil pressure, blow-by, coolant condition, alternator insulation, controller and protection, the enclosure and the documents. A load-bank test is the most telling single check.

Question 15

Can I sell or part-exchange my old generator?

Accepted Answer

Yes. We buy used generators and take sets in part exchange against a replacement. Value depends on make and parts support, hours, rating, emission era, condition and documents.

Question 16

Why are there no prices on this website?

Accepted Answer

Generator prices change constantly with engine supply, metal costs and emission norms, so a published figure would soon mislead. Send your requirement and we will reply with a current quotation.

Question 17

Does a generator installation need approval?

Accepted Answer

Yes, in most cases. Installations generally need electrical safety approval, and sets must carry valid emission and noise type approval; some sites also need pollution-board consent. The route depends on the rating and the site.

Question 18

What noise limit must a generator meet?

Accepted Answer

Sets up to 1,000 kVA must be supplied in an acoustic enclosure meeting the national limit of 75 dB(A) at 1 m. Placement still matters for neighbours, so distance and direction should be planned.

Question 19

Which documents should a generator owner keep?

Accepted Answer

The purchase invoice, type-approval and noise certificates, installation approval, warranty, commissioning and load-bank reports, and the service log. They matter for inspections, insurance claims and resale.

Question 20

Do I need a log book for my generator?

Accepted Answer

Yes, it is good practice and often expected during inspections. Record running hours, readings, fuel, faults and maintenance so problems show up early.

Question 21

What foundation does a generator need?

Accepted Answer

A level, reinforced concrete plinth sized for the set's weight and footprint, raised above flood level, with anti-vibration mounts. The foundation stops vibration travelling into the building and keeps the set aligned.

Question 22

Where should the generator be placed?

Accepted Answer

Somewhere with clear access for service and fuel delivery, good ventilation, a safe exhaust route and distance from windows and air intakes. A site-planning checklist avoids costly moves later.

Question 23

How should a generator be earthed?

Accepted Answer

With dedicated earth electrodes for the neutral and for the body, connected and tested as the earthing scheme requires. Poor earthing is a safety risk and causes nuisance tripping.

Question 24

How long can a generator run continuously?

Accepted Answer

It depends on the rating: prime and continuous sets are built for long running, while standby sets are meant for outages. Fuel, oil level and cooling are the practical limits, and oil must be checked during long runs.

Question 25

How often should a generator be serviced?

Accepted Answer

Typically oil and filters every 250 to 500 running hours or six months, whichever is earlier, and coolant every year; confirm against the maker's manual. The calendar limit matters because a standby set that rarely runs still ages. A planned schedule prevents most failures.

Question 26

Which engine oil and coolant should I use?

Accepted Answer

The grade and specification the engine maker lists for your engine and climate, with coolant mixed to the right concentration. Wrong oil or plain water in the radiator shortens engine life.

Question 27

How much diesel should I keep for a standby generator?

Accepted Answer

Enough for the running hours your worst credible outage needs, but not so much that the stock sits for many months. Size the stock against how fast you use it, rotate it first-in first-out, and check the tank regularly; stored diesel that ages picks up water and sludge.

Question 28

How many kWh does one litre of diesel give in a generator?

Accepted Answer

A healthy modern set at 50 to 100 % load typically produces about 3 to 3.8 kWh per litre (roughly 0.26 to 0.33 litres per kWh). At light load the figure falls sharply, so the same fuel buys fewer units.

Question 29

Is an AMC worth it?

Accepted Answer

For most standby sets, yes. A maintenance contract keeps the set serviced, tested and ready, which matters most during the outage you did not expect.

Question 30

How should I prepare my generator for summer?

Accepted Answer

Clean the radiator, check coolant and belts, keep ventilation clear and watch loading in high ambient heat. Summer is when undersized cooling shows itself.

Question 31

How should I prepare my generator for the monsoon?

Accepted Answer

Check the canopy seals, drainage around the plinth, earthing, battery and cable joints, and protect the set from flooding. Water in the alternator or air intake can cause serious damage.

Question 32

What are the most common generator myths?

Accepted Answer

Ideas such as running a set lightly loaded to save it, skipping oil changes on standby sets, or bigger always being safer cost owners money. Most myths come from experience with very different engines.

Question 33

Why will my generator not start?

Accepted Answer

The usual causes are a weak battery, poor connections, fuel supply problems, air in the fuel system or an active shutdown alarm. Check the controller's alarm first.

Question 34

Why does my generator start and then stop?

Accepted Answer

Usually a protection shutdown such as low oil pressure, overspeed or high temperature, a fuel supply problem, or a faulty sensor. The controller's fault record tells you where to look.

Question 35

What does black smoke mean?

Accepted Answer

Usually overloading, a restricted air supply or injector problems. Occasional brief smoke on a heavy load step is normal; persistent black smoke is not.

Question 36

Why is my generator overheating?

Accepted Answer

Blocked radiator fins, low coolant, a slipping belt, hot air recirculating, overloading or a faulty thermostat. Find the cause before resetting the shutdown.

Question 37

How do I know if my generator is overloaded?

Accepted Answer

Watch for black smoke, falling frequency and voltage, high temperature and breaker trips. Measure the current on each phase and compare it with the set's rated current.

Question 38

Why is my generator vibrating or noisy?

Accepted Answer

Worn or failed anti-vibration mounts, misalignment, loose parts, combustion faults or alternator bearing wear. Abnormal vibration should be investigated before it damages the set.

Question 39

The generator runs but gives no or low voltage. Why?

Accepted Answer

The usual causes are the AVR, loss of residual magnetism, excitation faults or wiring. Check the AVR and its fuse first.

Question 40

When is renting better than buying?

Accepted Answer

For short projects, seasonal peaks, events, planned shutdowns and while your own set is under repair. For long, frequent use, owning is usually better.

Question 41

Can we rent generators for an election count or exam centre?

Accepted Answer

Yes. Plan two sets so either can carry the critical load, placed outside the secured perimeter, with halls on generator before paper-start and refuelling agreed with security.

Question 42

What does a generator rental include?

Accepted Answer

The rental covers the generator. Transport is at actuals in the customer's scope, and cable and an operator are extra if you need them. The rental guide explains the terms.

Question 43

How much do power cuts really cost my business?

Accepted Answer

Add restart time, idle staff and scrap to the outage hours themselves. Our calculator works out the cost per outage, per month and per year from your own figures.

Generator Questions Answered: 43 Short Answers for Buyers and Owners

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