Rotor and stator matching guide

Match the Part Before You Order

Two generators can have the same power but use different windings, shafts, bearings, frames and mounting parts. Send the information below so we can compare the old unit before quoting.

Start with four photos View alternator parts

Why power alone is not enough

The electrical rating and the physical fit must both match

Manufacturers identify alternators by more than kW or kVA. Their documents also specify phase, voltage, frequency, winding, frame, bearing, adaptor and coupling. A correct replacement must agree with the original electrical design and mechanical connection.

Electrical match: Voltage, phase, frequency, power, winding and regulation system.
Mechanical match: Stator and rotor sizes, shaft, bearing, end bracket, flange and bolt pattern.
Exact identification: Model and serial number are the best starting point when the nameplate is readable.

First check - no dismantling

Send these four clear photos first

Many parts can be narrowed down before the alternator is opened. Keep every label readable and do not crop the edges of the machine.

Whole generator

One photo from the control-panel side and one from the alternator side.

Generator nameplate

Show brand, complete model, serial number, kW or kVA, voltage, frequency and phase.

Alternator label

Photograph any label or stamped number on the alternator body and end covers.

Sockets and wiring

Show the output sockets, breaker, voltage selector and visible wire plugs. Do not disconnect wires for the photo.

Second check - measurements

Measure in millimetres and show the ruler in each photo

Use a vernier caliper where possible. Write down the number and take a photo showing where the measurement starts and ends.

Generator rotor and stator measurement locations — Measure every item in millimetres and photograph where the measuring tool starts and ends. Dimensions must be checked together with the nameplate and mounting details.

A
Stator outside diameter
Measure across the widest outside edge of the stator body.
B
Stator inside diameter
Measure the clear inside opening where the rotor runs.
C
Stator core stack length
Measure only the iron lamination stack, not the winding ends or casing.
D
Rotor outside diameter and core length
Measure the rotor iron body across its diameter and along the lamination stack.
E
Shaft, bearing and total length
Record shaft diameter, bearing number or outside diameter, total rotor length, thread, keyway and any taper.
F
End bracket and mounting
Show the front and rear brackets, locating register diameter, bolt-hole spacing and rotor-end style.

Final check

Send one complete matching request

Keep all photos in one WhatsApp conversation. Include your town and province so stock and delivery can be checked at the same time.

Open the WhatsApp checklist

Generator and alternator nameplates Power, voltage, frequency and phase Whole-machine and control-panel photos Stator and rotor measurements Shaft, bearing, bracket and mounting photos Town, province and quantity required

Avoid a wrong order

Do not choose from one number or one photo

Do not order from kW or kVA alone.
Do not assume 220V, 230V and 240V windings are identical.
Do not rely on wire colour alone; send connector and terminal photos.
Do not treat a supplier dimension table as an industry-wide standard.
Do not change wiring or test an open alternator unless you are qualified.

Technical basis

Based on manufacturer identification and installation guidance

The practical checklist above is based on official manufacturer documents that identify model and serial number for parts ordering and separately specify electrical and mechanical configuration.