Sourcing diesel generating sets from China

Zero duty across the diesel output bands

Heading 8502 covers electric generating sets and rotary converters. This guide covers complete generating sets with compression-ignition diesel or semi-diesel engines. The diesel lines distinguish sets by electrical output in kVA. For other engine types and generating equipment, see the wider generator guide. For LPG-powered equipment, see sourcing LPG generating sets.

Read from the UK Trade Tariff on 1 October 2026, all listed diesel generating-set lines carried 0% duty for goods from China. The supplied tariff record lists no anti-dumping or countervailing duties, suspensions or attached import controls for these lines. Product safety and emissions requirements still need checking.

Confirm the complete set's engine type and rated electrical output against the tariff description before declaring it. A separately imported engine needs its own classification. Use finding your commodity code and ask your customs broker to check the selected line.

Specify the engine, output and tested canopy

State whether the set is for mobile hire, site work or permanent standby installation. Specify continuous and standby output separately, voltage, frequency, phase arrangement, starting method, alternator, control panel, sockets, earthing and residual current protection. Name the engine and alternator models, and agree the load-test acceptance criteria before production.

Ask for machinery conformity documents and electrical safety evidence for the complete configuration. The responsible person must ensure that the machinery technical file is compiled and available on request. For mobile sets, request the engine emission approval and matching engine plate details. Engine type approval demonstrates compliance with the latest emissions standards.

For outdoor power generators under 400 kW, confirm applicable noise limits and noise marking requirements with the relevant authority. Equipment within the outdoor noise rules must also come with a declaration of conformity. Specify the tested canopy, silencer and cooling arrangement, and obtain the noise report and guaranteed sound power label. Ask your testing and certification provider to confirm the current measurement methods for the model.

Worked duty example

Illustrative example, not a quote: Illustrative order of 75 compact diesel generating sets for a hire business under 8502 11 20 90, invoiced at £90,000 free on board, with £5,000 of freight and insurance to the UK. The customs value is £95,000. Duty at 0% is £0. Import VAT at 20% is charged on the customs value plus duty, £95,000, so it is £19,000. With no duty, the only import tax is the VAT, which a VAT-registered importer can usually reclaim. The import duty and VAT guide explains each step.

Inspection checklist

Identity and documents: match engine and alternator plates, model references and serial records to the approved specification and supporting documents. Check that the delivered canopy and exhaust match the noise-tested configuration.

Load performance: run sampled sets at the agreed continuous output. Record voltage and frequency stability, load response and signs of overheating. Measure waveform distortion where buyers intend to power sensitive electronics. For diesel rotary UPS procurement, see our diesel rotary UPS sourcing guide.

Electrical protection: check sockets, earthing, residual current protection, alternator insulation resistance and earth continuity. Inspect cable routing, terminals, guards and protection around hot surfaces.

Arrival condition: check for crate damage, corrosion, loose mounts and fuel-system leaks. Compare the noise label with the report and record discrepancies with photographs. Set the sampling and reporting brief through quality inspection.

What goes wrong

A quoted output may be a peak rating that the set cannot sustain. Weak regulation shows up as voltage or frequency sag under load. Fuel joints can leak, measured noise can exceed the label, and the engine plate can disagree with the emission approval. A canopy substitution also makes the supplied noise report a poor match for the delivered set.

Keep the approved engine, alternator, canopy and control-panel configuration attached to the purchase specification. Require agreement before substitutions, retain the load-test records and check the same configuration on arrival. Agree filters, starter parts, service instructions and spare-part identification before ordering.

Cambridge China Bridge sources these products for UK businesses, checking the factory and the documents before shipment. See factory verification. For components and parts, see sourcing for manufacturers.