In short. A 15 kVA generator delivers 12 kW at 0.8 power factor, which is about 20.9 A per phase on a 415 V three-phase set or about 65 A on a 230 V single-phase set. In Hyderabad it typically carries a showroom, a small school block, a bank-branch-style office with an ATM, or the common loads of a 6–12 flat building that has no lift. It is also the smallest size in which Reddy Generators offers used and refurbished sets, alongside new CPCB IV+ sets supplied through tie-ups with all major makes, rental, and service for every make. The price is given on request, because it depends on the specification described below.
Who this page is for: Owners of showrooms, small schools, branch offices, clinics and small residential buildings in Hyderabad who are considering a 15 kVA generator, and anyone pricing a new, used or rental 15 kVA set.
Key facts
- Output: 15 kVA = 12 kW at 0.8 PF, equal to about 16 HP of electrical output. The engine behind it develops more than that, roughly 18–21 HP at the flywheel depending on the make.
- Full-load current: 20.9 A per phase at 415 V three-phase (15 × 1.391), or 65.2 A at 230 V on a single-phase set (15 × 4.348).
- Diesel use (approximate): 1.8–2.0 L/h at 50 % load (6 kW) and 2.6–2.9 L/h at 75 % load (9 kW), based on 0.29–0.33 L per kWh. The make’s data sheet gives the actual figure.
- Phase: three-phase 415 V is the usual build. Single-phase 230 V versions exist from some makes.
- Noise: new sets are canopied to the CPCB IV+ limit of 75 dB(A) at 1 m.
- Breaker and cable (three-phase): 25 A four-pole MCCB, 40 A four-pole changeover, 4-core 16 sq mm aluminium armoured cable for routes up to about 140 m. See the breaker, changeover and cable chart.
- Largest direct-on-line motor (rule of thumb): about 3 HP. A 5 HP motor needs star-delta or a soft starter.
- Typical uses: showrooms, small schools, branch offices and ATMs, clinics, and common loads of small residential buildings.
Get price
Generator prices change every day, so we do not print them on the website. Tell us whether you want to buy new, buy used or rent a 15 kVA set, single or three phase, and where the site is. We will send the price.
- New set: the price excludes GST, transport and installation.
- Rental: the rate covers the generator only. Transport is charged at actuals and is in the customer’s scope. Cable and an operator are extra charges if you need them.
- Used or refurbished: priced set by set on make, running hours and condition. Every set is load-bank tested before sale; refurbished sets carry a six-month warranty (rubber and plastic parts, consumables, fuel damage and overload excluded); used sets sold as-is come with an inspection report.
Get price on WhatsAppCall 98852 01608Purchase enquiryRental enquiry
The general method is in our 15–50 kVA planning guide. This page does the arithmetic for 15 kVA only.
What a 15 kVA generator can run
For continuous running, plan on about 75–80 % of the rating, which is 9–9.6 kW. The remaining margin is for motor starts, summer derating and loads added later. The table uses typical Hyderabad load sets. Running kW figures are approximate input power and assume that only the loads listed are wired to the generator.
| Site and load set | Running load (approx.) | Hardest start | Fits 15 kVA? |
|---|---|---|---|
| Showroom: LED display and track lighting 2.5 kW, three 1.5-ton fixed-speed split ACs, billing PC, CCTV | about 8.2 kW | One AC compressor, 3–5 × its running kW for a moment | Yes, if the ACs restart one at a time (staggered restart delay) |
| Bank-branch-style office: 8 PCs on a 2 kVA UPS, lighting 1 kW, two 2-ton ACs, ATM | about 7.5 kW | AC compressor; UPS recharge after the outage | Yes. The UPS stays well under 40–50 % of the set rating |
| Small school block (no classroom ACs), computer lab, office, 3 HP borewell | about 9.5 kW | 3 HP pump, about 20 kVA DOL | Yes. See the illustrative case below |
| 6–12 flat building without a lift: sump and borewell pumps (2 HP each, one at a time), common lights, gate and CCTV, 0.5 kW DG point per flat (12 flats) | about 8.5 kW | 2 HP pump, about 13 kVA DOL | Yes |
| Clinic: two consulting rooms with inverter ACs, pharmacy fridge, reception, lab analysers | about 5–6 kW | Fridge compressor | Yes, with room to spare. Check X-ray or other imaging equipment with its supplier first |
| Cold room with a 5 HP condensing unit, plus a shop | about 6 kW | 5 HP compressor, about 33 kVA DOL | No, unless the compressor has a soft starter. Look at 20–25 kVA |
How many ACs can a 15 kVA generator run?
The honest answer is three fixed-speed 1.5-ton split ACs or four inverter units, with lights, fans and computers also running. A fixed-speed 1.5-ton split draws about 1.5–1.8 kW in a Hyderabad summer and three to five times that for a moment at start-up; an inverter AC ramps up with no surge worth planning for. Six inverter units alone (about 8.4 kW, two per phase) would fit on paper, but that leaves nothing for lights, computers or a pump, and little margin in May, when the engine is also derated.
On a three-phase set each phase carries only 5 kVA (4 kW), and two fixed-speed ACs plus that phase’s lights use most of it. Spread the ACs across the phases and give each a different restart delay.
Motor-starting limit
As a rule of thumb, a set in this class accepts a direct-on-line start of up to about 1.5 times its rating, with a voltage dip that contactors and most electronics ride through. For 15 kVA that is about 22 kVA, which covers a 3 HP motor but not a 5 HP motor (more than twice the rating). With star-delta, starting kVA falls to about one third, so a 5 HP star-delta pump (about 11 kVA) is acceptable. For anything above 3 HP, send us the nameplate. The motor-starting guide explains the method.
Diesel consumption per hour
Basis: 0.28–0.33 litres per kWh between half and full load, worse at quarter load. Figures are approximate; the make’s data sheet decides. The runtime column assumes a 50 L base tank for illustration, as tank sizes vary by make.
| Load | Output | L per kWh (approx.) | Litres per hour (approx.) | Runtime on 50 L |
|---|---|---|---|---|
| 25 % | 3 kW | 0.36–0.42 | 1.1–1.3 | about 40–46 h |
| 50 % | 6 kW | 0.30–0.33 | 1.8–2.0 | about 25–28 h |
| 75 % | 9 kW | 0.29–0.32 | 2.6–2.9 | about 17–19 h |
| 100 % | 12 kW | 0.28–0.31 | 3.4–3.7 | about 13–15 h |
Per kWh, quarter load burns about a quarter to a third more diesel than three-quarter load, and hours at 2–3 kW cause wet-stacking (see the light-load guide).
Monthly fuel worksheet
Multiply line F by the current diesel rate.
| Line | Example (school, below) | Your site |
|---|---|---|
| A. Outage hours per day on the generator | 2 h | |
| B. Working days per month | 22 | |
| C. Run hours per month (A × B) | 44 h | |
| D. Average load in kW (from your load list) | 9.4 kW | |
| E. Litres per hour at that load (table above) | 2.7–3.0 L/h | |
| F. Litres per month (C × E) | about 120–133 L |
Single phase or three phase at 15 kVA
Choose single phase (230 V, about 65 A) only when the premises has a single-phase supply and all the loads are single-phase, for example a large independent house or a shop where no motor is three-phase. All 12 kW is then on one circuit, with no balancing, but the changeover is heavier (80 A two-pole), the cable thicker and the choice of models narrower.
Choose three phase (415 V, about 20.9 A per phase) when the building has a three-phase supply or any three-phase motor, such as a borewell, a sump pump or a lift. Makers commonly allow 10–20 % unbalance between phases. Aim for the lower end: an overloaded phase overheats its winding and the light phases drift up in voltage.
The AVR question
The automatic voltage regulator is a small electronic card on the alternator that controls excitation and holds the output steady, typically within about ±1–2.5 % between no load and full load, depending on the make.
| Symptom on your set | Possible cause | What to check before buying an AVR |
|---|---|---|
| No output voltage, engine running normally | Failed AVR, lost residual magnetism, open exciter field, failed rotating diodes | Rotating diodes and exciter resistance. A new AVR will not fix a shorted diode |
| Voltage too high (for example 260–280 V phase to neutral) | AVR sensing lead loose or AVR failed | Sensing connections. High voltage damages electronics quickly, so stop the set |
| Voltage hunting or lamps flickering | AVR stability setting, or engine speed hunting | Whether frequency is also swinging. If it is, the cause is on the engine side |
The AVR price depends on the alternator make and model, sensing type, and original or compatible unit, so we quote from the alternator nameplate. Our engineers do AVR and controller work on all makes; see the low-voltage guide. A servo stabiliser is a different device. It corrects mains voltage and does not replace a healthy AVR on the generator (see the stabiliser kVA calculator).
How the price of a 15 kVA set is worked out
Two 15 kVA sets can be specified very differently. The price moves with:
- Phase: single-phase 15 kVA sets are offered by fewer makes; three-phase is the usual build.
- Make and engine: engines at this size have two, three or four cylinders. Makes differ in transient response, parts availability and service intervals.
- Canopy: a silent canopy meeting the CPCB IV+ limit is standard on new sets, so check that it is included rather than treating it as an option.
- Starting and control: a manual-start set with a basic controller, an auto-start set, or a set with a full AMF panel and changeover.
- Battery and controller: battery capacity, a charger for auto-start duty, and the controller features.
- Fuel tank: the standard base tank, or a larger or external tank for long outages.
- Warranty: period, and what the engine, alternator and canopy each carry.
- New, used or rent: 15 kVA is the smallest size we offer used. A refurbished set carries our six-month warranty. A used (as-is) set comes with an inspection report and no warranty. Rental is quoted per period.
To compare quotations line by line, see the price guide.
Get price on WhatsAppCall 98852 01608Purchase enquiryRental enquiry
Buy new, buy used or rent a 15 kVA set
| Your situation | Usually the better route | Why |
|---|---|---|
| Standby for a school, shop or office: under 20 run hours a month, needed for years | Refurbished or new | Low hours suit a refurbished set with warranty; new gives the longest life |
| Daily outages or a weak feeder: 60–150 hours a month, needed for years | New | High hours favour a new engine and maker’s warranty |
| Construction site, fit-out, event or temporary office: days to 12 months | Rent | No capital tied up; the set goes back when grid power arrives |
| Tight budget, standby only, and a buyer who wants to see the set first | Used (as-is) with inspection report | Lowest outlay, no warranty; read the inspection report |
| Your own set is going in for overhaul | Rent for the overhaul period | Keeps the building supplied during the work |
Whether a rental 15 kVA set is available for your dates is confirmed when you ask. Rental terms are on the rental rates page, and the used range is on the used and refurbished generators page.
Installation and site needs in Hyderabad
- Footprint: a canopied 15 kVA set is roughly 1.6–2.2 m long, 0.8–1.0 m wide and 1.1–1.4 m high, and weighs roughly 600–950 kg with fuel. The make decides. Allow about 1 m clear around it, more at the radiator outlet.
- Plinth: a level RCC plinth a little larger than the base frame, raised above the highest water level seen in the monsoon. Cellar corners that water-log after heavy rain are poor locations.
- Exhaust: in narrow lanes and apartment setbacks, point the exhaust away from neighbours’ windows, the security cabin and AC condenser intakes.
- Earthing: provide earth electrodes for the neutral and the body as the installation rules require. See the DG earthing guide.
- Cable and breaker: use the 25 A MCCB, 40 A changeover and 16 sq mm aluminium figures above. Recheck them for long or buried routes.
- Auto-start: for a school, branch or clinic with no one on site to start the set, an AMF panel starts the set and changes over in about 10–20 seconds. Anything that cannot tolerate that break needs a UPS.
- Summer heat: Hyderabad regularly passes 40 °C in April and May, and the air inside a canopy is hotter. Check the derating on the data sheet, and do not load the set past 80 % for long runs. See summer precautions.
All connections and the changeover must be made by a competent, licensed electrician. The changeover must be interlocked so that the generator can never feed back into the DISCOM line.
Illustrative case: a small school on a three-phase 15 kVA set
Illustrative case. A primary school in the eastern suburbs has ten classrooms, a computer lab, an office and a borewell. Outages hit during school hours, about two hours a day.
| Load | Basis | Running kW |
|---|---|---|
| Classrooms | 10 rooms × (4 LED fittings × 20 W + 3 fans × 60 W) | 2.6 |
| Computer lab | 15 PCs × 100 W (small-form-factor PCs, LED monitors) | 1.5 |
| UPS recharge allowance | Lab UPS after the outage | 0.3 |
| Office | 2 PCs, printer, one 1.5-ton inverter AC | 1.9 |
| Staff room | Lights and fans | 0.4 |
| Borewell | 3 HP submersible: 2.24 kW ÷ 0.82 efficiency | 2.73 |
| Total | 9.43 |
Size check. 9.43 kW ÷ 0.8 PF = 11.8 kVA, which is 79 % of 15 kVA, inside the 75–80 % planning band. The borewell start of about 20 kVA is within the 1.5 × rule, but it should not coincide with the lab coming on, so the pump is set to start a minute after changeover.
Phase check. Each phase can carry 4.0 kW. With half the classrooms and half the lab on R, the other halves plus the UPS on Y, and the office and staff room on B, and the pump’s 0.91 kW on each phase, the totals are R 2.96, Y 3.26 and B 3.21 kW. The spread from the heaviest to the lightest phase is about 10 % of the average, within the 10–20 % allowance.
Fuel. At 9.4 kW (about 79 % load) and 0.29–0.32 L/kWh, the set uses about 2.7–3.0 L/h. For 2 h × 22 days = 44 h, that is about 120–133 litres a month, before test runs.
Choice. At about 44 hours a month, between the standby and daily-outage rows of the table above, a refurbished 15 kVA set with an AMF panel and a new one are both sensible options. If classroom ACs are planned, go straight to 20–25 kVA.
Get-price request sheet for a 15 kVA set
Send this with your enquiry so the quotation can be firm first time.
| Question | Your answer |
|---|---|
| Buy new, buy used/refurbished, or rent? | |
| Supply at the premises: single-phase or three-phase? | |
| Largest motor (HP) and its starter type (DOL, star-delta, soft starter) | |
| Number and type of ACs (fixed speed or inverter, tonnage) | |
| UPS rating, if any (kVA) | |
| Manual start, auto-start, or full AMF with changeover? | |
| Site location (area in Hyderabad, or district) | |
| Generator position: ground, terrace, setback or cellar? Distance to the main board (m) | |
| Photos attached: main DB, proposed location, existing set nameplate | |
| Required delivery date |
Common mistakes
- Buying a three-phase 15 kVA set for a building whose loads are all single-phase, then finding that only about 5 kVA is available on any one phase.
- Expecting a 15 kVA set to start a 5 HP pump or cold-room compressor direct-on-line. Without star-delta or a soft starter, that needs about 20–25 kVA.
- Replacing the AVR when the real fault is a failed rotating diode or a loose sensing lead, then paying for a second visit.
- Wiring geysers, ovens or every AC on the premises to the generator board, so the set runs above 80 % through the summer and shuts down on high temperature.
What to send us
For a 15 kVA price, tell us whether you want to buy new, buy used or rent; whether the supply is single-phase or three-phase; whether you need manual start, auto-start or a full AMF panel; the site location in or outside Hyderabad; a load list or photographs of the main distribution board; the delivery date; and, for rental, the duration. Use the generator sales enquiry, or WhatsApp the details and photographs.
Questions buyers ask about 15 kVA generators
What is the price of a 15 kVA generator in Hyderabad?
There is no fixed figure, because the price depends on phase, make, canopy, manual or auto-start, AMF panel, tank and warranty, and on whether you buy new, buy used or rent. A new-set quotation excludes GST, transport and installation. A rental rate covers the generator only, with transport at actuals. Send your load list, phase and site location on WhatsApp and we will reply with a written quotation.
How much diesel does a 15 kVA generator use per hour?
Approximately 1.8–2.0 litres per hour at half load (6 kW), 2.6–2.9 L/h at 75 % load (9 kW), and about 3.4–3.7 L/h at full load (12 kW). The make’s data sheet gives the exact figure, and a set running at very light load uses more diesel per unit of power.
How many ACs can a 15 kVA generator run?
About three fixed-speed 1.5-ton split ACs, or four inverter units, with lights, fans and computers also running. Spread them across the three phases and set their restart delays differently so that the compressors do not all start at once.
How many amps is a 15 kVA generator?
20.9 A per phase on a 415 V three-phase set, and 65.2 A on a 230 V single-phase set. Use a 25 A four-pole MCCB and a 40 A changeover for the three-phase version.
How many HP is a 15 kVA generator?
Its electrical output of 12 kW equals about 16 HP. The engine develops more, roughly 18–21 HP depending on the make, to cover alternator and cooling-fan losses. The largest motor it can start direct-on-line is about 3 HP.
Is a second-hand 15 kVA generator available?
Yes. 15 kVA is the smallest size in our used and refurbished range. Every set is load-bank tested. Refurbished sets carry a six-month warranty (rubber and plastic parts, consumables, fuel damage and overload excluded). Used (as-is) sets come with an inspection report and no warranty. Availability is confirmed when you ask.
Can I rent a 15 kVA generator in Hyderabad?
Yes. Ask with your dates and site location, and we will confirm whether a set of this size is available. The rate covers the generator only. Transport is at actuals and in your scope, and cable and an operator are charged extra if you need them.
What does the AVR on a 15 kVA generator do, and what does it cost?
The AVR holds the alternator’s output voltage steady. Before replacing it, check the rotating diodes and sensing leads, because a new AVR will not fix those faults. The price depends on the alternator make and model, so send the nameplate photo for a quotation.
Related pages
- 10 kVA generator in Hyderabad
- 20 kVA generator in Hyderabad
- 15–50 kVA generator planning guide
- Used and refurbished generators
- Diesel generator price guide
- Generator rental rates in Hyderabad
- Full-load current chart
- Low voltage or no output: troubleshooting
Technical content reviewed by D. Srinivas Reddy, Managing Partner and service engineer. Last updated 5 November 2026.