Transformer delivery to Uzbekistan: step-by-step process

Transformer delivery to Uzbekistan from a Chinese factory is a sequence of defined steps: specification, offer, contract, production, factory acceptance tests, transport across Kazakhstan and customs clearance in Uzbekistan. This article describes each stage as LALOGO and Jiangsu Xinhong Electrical Equipment run it, with typical durations and the documents an engineer or procurement manager should expect. The durations are typical values from our practice, not guarantees; the schedule for a specific order is fixed in the contract.

Step 1. Specification and offer

A usable offer starts with a complete specification. For a distribution transformer we ask for the following minimum data:

• Rated power (kVA) and number of units.
• HV voltage (6, 6.3 or 10 kV in Uzbek distribution networks), LV voltage (0.4 kV), 50 Hz.
• Vector group (Yyn0 or Dyn11 for the S13 series) and tapping range (±5 % or ±2×2.5 %).
• Type: oil-immersed hermetically sealed, or dry-type cast resin for indoor installation.
• Required loss level or energy-efficiency class, if the tender defines one.
• Site conditions: altitude, ambient temperature range, indoor or outdoor, seismic requirements.

For a box-type substation (KTP) the list grows: HV incoming scheme, HV switch type, number and ratings of LV feeders, metering and enclosure layout. For a switchgear lineup we need the single-line diagram, busbar current, short-circuit current and the protection scheme.

Example: a customer asks for a 1000 kVA, 10/0.4 kV unit. We offer S13-M-1000 with no-load loss 830 W, load loss 10 300 W, no-load current 0.6 % and short-circuit impedance 4.5 %. If the tender requires lower no-load loss, we quote an energy-efficiency grade 1 oil-immersed transformer instead. The offer includes data sheets, an outline drawing, delivery time and the Incoterms basis.

Step 2. Contract and payment terms

The contract fixes what the offer described: model, quantity, technical parameters, delivery basis, packing, delivery date, warranty and payment schedule. Points to check before signing:

• Technical annex. The data sheet with guaranteed losses, impedance and noise level becomes part of the contract. Losses measured at the factory acceptance test are checked against it; unless the contract states tighter values, the tolerances of IEC 60076-1 apply (+10 % on total losses, +15 % on each of no-load loss and load loss).
• Delivery basis. Common options are FCA factory, DAP border (Khorgos or Alashankou) or DAP Tashkent. The choice decides who arranges Kazakhstan transit and Uzbek customs.
• Payment schedule. A typical structure is an advance payment at signing and the balance before shipment or against shipping documents.
• Acceptance. The contract names the tests to be witnessed, who attends, and how remote witnessing is organised.

Step 3. Production and factory acceptance tests

Production at the Pizhou plant takes 20–45 days from the advance payment, depending on model and quantity. Standard S13 units of 100–1000 kVA are at the lower end; 35 kV transformers, complete KTP with switchgear and multi-panel lineups take longer because of engineering and secondary wiring.

Every unit passes routine tests before it leaves the plant. For an oil-immersed transformer the programme follows the IEC 60076 series and includes:

1. Winding resistance measurement.
2. Voltage ratio on all tap positions and vector group check.
3. No-load loss and no-load current at rated voltage.
4. Load loss and short-circuit impedance at rated current.
5. Separate-source (applied) and induced AC withstand voltage tests.
6. Oil breakdown voltage and tank tightness test.

For a KYN28A-12 lineup (12 kV, up to 4000 A, 31.5 kA) the routine tests follow IEC 62271-200 and are different: power-frequency withstand of the main and auxiliary circuits, main-circuit resistance, mechanical operation of the withdrawable truck, and a functional check of the five-prevention interlocks. The enclosure is rated IP4X; between compartments and with the breaker compartment door open it is IP2X.

The customer or a nominated engineer is invited to witness the factory acceptance test (FAT). If travel is not practical, the tests can be recorded on video and the report is sent the same day. The plant holds ISO 9001, 14001 and 45001 certificates; Jiangsu Xinhong's XL, GGD, GGJ and XMCS-K low-voltage cabinet types hold CCC certificates, and selected transformer, switchgear and substation models have been type-tested by national and CNAS-accredited test laboratories in China. Details are on the certificates page.

Step 4. Documents that accompany the shipment

The document set is prepared in parallel with the FAT and checked before packing. A complete set for a transformer order includes:

For KTP and switchgear the set also contains the single-line diagram, secondary wiring diagrams and the list of installed apparatus. Drawings are supplied in Russian or English as agreed; we recommend reviewing the foundation and cable-entry drawings before production starts.

Step 5. Export packing and transport route

Hermetically sealed distribution transformers up to 2500 kVA are shipped oil-filled and fully assembled, bolted to a skid with the bushings protected by wooden framing. For larger 35 kV power transformers the radiators and conservator may be removed and the tank shipped under dry air or nitrogen; the method is stated in the packing specification. Dry-type transformers are wrapped in moisture-barrier film with desiccant and boxed. Switchgear typically travels in transport units of two to four panels, with withdrawable trucks and relays packed separately. Box-type substations such as the YB European-type prefabricated substation travel as complete units on flat wagons or low-bed trucks, with secondary wiring completed and tested at the factory, so on site only the HV and LV cable connections and the earthing remain.

The main route from Pizhou to Tashkent is rail:

• Rail from Jiangsu to the Chinese border at Khorgos or Alashankou.
• Transshipment from 1435 mm standard gauge to 1520 mm broad gauge at the Kazakh border stations (Altynkol or Dostyk).
• Transit through Kazakhstan to the Uzbek border and on to Tashkent.

Transit time from the factory gate to Tashkent is typically 15–25 days, including border handling. Road transport via Khorgos is used for urgent orders or oversized single units at a higher cost per tonne. Whoever contracts the forwarder, we send the packing list with dimensions and weights in advance so that unloading equipment can be arranged.

Step 6. Customs, certification, installation and warranty

Import formalities and the conformity documents required for electrical equipment in Uzbekistan are handled together with our local partners in Tashkent. Which certificates apply depends on the product and the customer's status, so we confirm the list for each contract at the offer stage rather than assuming a standard set; the certificate of origin and test reports prepared at the factory must match the product description in the declaration.

After arrival, the following on-site programme is typical for a transformer or a KTP:

• Visual inspection for transport damage and impact indicators.
• Insulation resistance of windings, voltage ratio and vector group check.
• Oil breakdown voltage sample test for oil-immersed units after transport.
• For KTP and switchgear: check of interlocks, secondary circuits and protection settings.
• Energisation at no load, then connection of load.

LALOGO provides installation supervision by a manufacturer's engineer on request; the scope and number of days are fixed in the contract. The standard warranty is 12 months, with a 4-hour response to a reported fault; the start date (delivery or commissioning) is written in the contract.

Transformer delivery to Uzbekistan: checklist

• Send a full specification: kVA, voltages, vector group, taps, loss requirement, site conditions.
• Check the technical annex of the contract against the offer data sheet.
• Fix the delivery basis (FCA, DAP border, DAP Tashkent) and who handles Kazakhstan transit.
• Plan 20–45 days for production and 15–25 days for transport; add time for customs clearance.
• Attend or remotely witness the FAT; keep the routine test report with the passport.
• Confirm the Uzbek conformity documents with the local partner before shipment.
• Agree supervision days, warranty start date and spare parts in the contract.

If you are preparing a tender or a project order and need delivery times and technical data for specific units, send the specification through the contact page and we will return an offer with data sheets, drawings and a delivery schedule for your site.