Sourcing generator synchronising panels from China

Duty on generator synchronising panels

Heading 8537 covers equipped panels and cabinets for electrical control or distribution. Distinguish a complete generator synchronising panel from a separately imported programmable controller. The higher-voltage rows describe equipped assemblies of that rated voltage, rather than every control cabinet connected to higher-voltage switchgear. For the wider heading, see the automatic transfer switch panels guide.

Read from the UK Trade Tariff on 30 September 2026, the selected lines carry 2% duty on goods from China, with no anti-dumping or countervailing duty recorded. Conditional 0% suspensions cover specified electronic products or authorised uses, including offshore wind substation systems. These do not automatically make an ordinary synchronising panel duty-free.

The selected lines attach fluorinated greenhouse gas import control. Imported equipment containing these gases must be correctly labelled. Tell your customs broker whether the assembly contains gas, its type and charge, and confirm the applicable declaration requirement, including for gas-free panels. Confirm the commodity code from the drawings, rated voltage and configuration as imported.

Specify synchronisation and load sharing

State whether generators parallel with each other, with the mains, or both. Provide generator ratings, governor and voltage-regulator interfaces, breaker operating times, sensing arrangements and the required operating sequence. Define voltage, frequency and phase matching, active and reactive load sharing, reverse-power protection, dead-bus closing and behaviour after communication loss. Agree the settings and acceptance procedure with the project engineer.

Specify controller and breaker models, busbar rating, prospective fault current, enclosure protection, cable entries and terminal identification. Require approved schematics, a bill of materials, editable programme backups and assembly verification records. Agree who commissions the panel and releases the final settings.

For Great Britain, assess electrical safety requirements against the equipment's rated supply and electromagnetic compatibility requirements for its electronics. Obtain complete-assembly technical documentation, a declaration of conformity, CE or UKCA marking and importer identification where applicable. Assess hazardous-substance restrictions and any applicable exclusions. Equipment within the electrical safety rules must have instructions in easily understandable English. Use testing and certification to review model-specific evidence.

Worked duty example

Illustrative example, not a quote: Illustrative order of 20 generator synchronising control panels for a small electrical contractor, not a quotation under 8537 10 98 99, invoiced at £30,000 free on board, with £1,800 of freight and insurance to the UK. The customs value is £31,800. Duty at 2% is £636. Import VAT at 20% is charged on the customs value plus duty, £32,436, so it is £6,487.20. Import taxes total £7,123.20; a VAT-registered importer can usually reclaim the VAT, so the lasting cost is the £636 of duty. The import duty and VAT guide explains each step.

Inspection checklist

Components and wiring: check controller, breaker and relay models against the approved bill of materials. Verify sensing polarity, phase identification, breaker feedback, protective connections and terminal labels.

Synchronising logic: witness the agreed simulation of voltage, frequency and phase mismatch. Check that closing is inhibited outside the approved conditions and that breaker feedback changes the sequence correctly.

Load sharing and faults: witness agreed active and reactive load-sharing tests, load changes, generator loss, communication loss and recovery. Record controller settings, alarms and the final programme version.

Arrival and records: check moisture, frame damage, loose components and cable-entry protection before installation. Match labels, drawings and test records to the delivered panels. Plan checks using the quality inspection guide.

What goes wrong

A demonstration can show breakers closing while hiding incorrect sensing polarity, governor interfaces or closing-time compensation. Require tests using the intended generator interfaces or an agreed simulation. Keep a site commissioning procedure because a factory demonstration cannot establish performance with the installed generators.

Controller substitutions, locked programme files and changed protection settings can leave the delivered panel different from the approved design. Require written approval for substitutions and retain a tested backup. Treat mains paralleling as a separate project configuration, with its connection conditions confirmed before approving the design.

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.