In short. A generator spare parts enquiry succeeds when the part is identified from the equipment, not from its appearance. Send photographs of the generator, engine and alternator nameplates, the serial number, the existing part number and a photograph of the part, the quantity, the reason for replacement and the location. Reddy Generators then checks compatibility against the actual configuration before confirming supply, price and delivery in writing.
Send your enquiry
Why the genset rating is not enough
A 125 kVA generator is not one machine. The same rating is built by different makers with different engines, alternators and controllers, and the same model may change engine variant, filter specification or controller over its production life. Two engines that look alike can differ in bore, injector type, turbocharger or bearing size. An engine that has been overhauled may carry undersize bearings or oversize liners that the nameplate does not show. The genset rating therefore identifies almost nothing about a part. The identification chain runs from the nameplate to the serial number, then the part number, the technical documentation, the installed configuration and finally physical verification. See parts compatibility verification for how each link is checked.
What to include
| Item | Example | Why it matters |
|---|---|---|
| Generator nameplate photograph | Make, model, kVA, serial, year | Identifies the set and its build |
| Engine or alternator nameplate | Engine model and serial, alternator frame | Parts follow the component, not the set |
| Existing part number | Stamped or labelled on the part | Most reliable reference |
| Part photographs | Several angles, connectors, markings | Confirms variant and fitment |
| Reason for replacement | Failure, wear, planned maintenance, overhaul | May reveal a root cause or related parts |
| Quantity and urgency | Number required, set down or running | Prioritises sourcing |
| Location | Site town or address | Delivery and fitting arrangements |
If a serial number is unreadable, send several clear photographs rather than guessing a digit. A wrong digit can point to a different engine build.
Part families and their identification needs
Engine parts
The engine is the most parts-intensive subsystem. Filters, belts and hoses usually need the engine model and serial. Injectors, fuel pumps and turbochargers need the exact part number because variants differ within one engine family. Bearings, pistons and liners need measurements and overhaul history as well. Critical fasteners such as head and connecting-rod bolts should be genuine specification parts, not visually similar commercial hardware. See engine parts.
Alternator and excitation parts
AVRs, rotating diodes, exciters and bearings follow the alternator frame and its excitation system, whether self-excited or PMG. An AVR that fits the terminals may not suit the sensing or excitation of the alternator. Send the alternator nameplate and the AVR label.
Controller, sensors and switchgear
Controllers, senders, contactors and breakers need the model and rating, and for controllers, the software or firmware version where a replacement must reproduce existing settings. A replaced controller needs its configuration reloaded and the start and transfer sequence tested.
Compatibility before supply
A matched reference does not establish stock, price or delivery, and an enquiry does not approve a cross-reference or place an order. Where required, the manufacturer or supplier confirms the reference before we supply. Final compatibility, availability, specification, price, warranty and terms are confirmed in a written quotation. Genuine parts are supplied where available; if an alternative is proposed, the quotation says so. Our policy on used or refurbished parts is set out in used and refurbished parts policy.
Batteries, filters and consumables
Even routine items need identification. Starting batteries must match the voltage, cold cranking capacity and terminal layout required by the starter and the space in the battery tray. Fuel filters on CPCB IV+ common rail engines often have finer filtration and water separation requirements than older engines, and fitting an older-specification filter risks injector damage. Lube oil should meet the grade and specification in the engine manual, particularly for engines with aftertreatment. Send the engine model and the existing filter or battery label, and we will confirm the correct item. See generator filters.
Keeping a record for next time
For a set you maintain regularly, keep an equipment record listing the nameplate details, confirmed part numbers for filters, belts, batteries and common wear parts, and any overhaul history with sizes. It removes repeat identification work and avoids ordering errors during a breakdown. The find my generator part guide explains what to photograph.
Common mistakes
- Ordering by genset kVA; the part supplied fits a different engine variant and the set stays down.
- Ordering bearings without overhaul history; standard size arrives for an undersize crankshaft.
- Replacing an AVR by appearance; the new unit does not match the sensing and voltage hunts on load.
- Replacing a failed part without asking why it failed; the new part fails for the same reason.
What to send us
Send the generator nameplate photograph, engine or alternator nameplate where relevant, the existing part number and photographs of the part, the reason for replacement, quantity, urgency and location. Phone or WhatsApp 098852 01608 or email info@reddygenerators.com, or contact Reddy Generators through the form with the photographs attached.
Questions engineers ask
Can you supply parts for older generators?
Often, for common makes and engines still supported. For obsolete engines, parts may come from remanufactured or alternative sources, which we state in the quotation after checking compatibility.
Do you supply genuine parts?
Genuine parts are supplied where available. If an alternative is proposed, the quotation identifies it so you can decide.
What if the part number has worn off?
Send the nameplates and several photographs of the part, its connectors and markings. We can usually identify it from the engine or alternator build, and measurements can confirm it.
Can you fit the part as well?
Yes, supply and fitting can be quoted together, with testing after fitting. State the location and whether the set is down.
How quickly can parts be supplied?
Common service items such as filters, belts and batteries are usually quick to source. Specific engine, alternator and controller parts depend on supplier stock and may need manufacturer confirmation, so the quotation states the delivery time.
Technical content reviewed by Srinivas Reddy, Managing Partner, Reddy Generators. Last updated 19 October 2026.