Turkmenistan – Offshore oil and natural gas facility (Caspian), 1250 kVA

The request

The work step by step

1. 1. Tender specification received

   • The request arrived with the end user's generator datasheet: 239 numbered lines to be answered line by line.
   • The lines cover electrical, mechanical, environmental, hazardous-area, coating, control and documentation requirements.

2. 2. Specification and project analysis

   • Site: offshore wellhead platform with saline, dusty and corrosive air, −20 to +50 °C and 86 % humidity; at sea level, so no altitude derating.
   • Duty: the datasheet asks for 1250 kVA prime in continuous operation from 10 to 100 % load and 110 % for one hour.
   • Electrical system: 400/230 V, 50 Hz, 3-phase; the set must synchronise with other sets in island mode.
   • Hazardous area: Zone 2. Certification of the whole package is not required; individual components must be Ex-certified (ATEX/IECEx) and the exhaust needs a Zone 2 certified spark arrester.
   • Standards: ISO 8528-1, ISO 3046-4, IEC 60034 and BS 4999.

3. 3. Product selection

   • Base model TRX P ST 1250: Perkins 4008-30TAG3 engine with a Stamford S6L1D-F4 alternator, 1250 kVA standby / 1125 kVA prime. Its prime rating is below the 1250 kVA prime asked, and we stated this as a deviation.
   • To meet 1250 kVA prime without deviation we also offered TRX P ST 1500 (Perkins 4012-46TWG3A, Stamford S6L1D-H4, 1350 kVA prime) with its own signed datasheet.
   • The buyer preferred the 1250 kVA model; the following work was built on it.
   • Excitation upgraded to PMG with MX321 AVR (±0.5 %); alternator reactances, time constants and short-circuit data taken from the alternator manufacturer's datasheet.
   • +50 °C ambient checked against engine data; the high-ambient rating is marked for confirmation with the engine manufacturer. The alternator inlet filters reduce alternator output by about 5 %, and this is noted on the datasheet.
   • Fuel: the base tank on the skid covers at least 8 hours at 100 % prime.

4. 4. First offer

   • Base scope: canopy set with base tank, controller, factory load test and documentation.
   • Deviation list: every datasheet line was answered as comply, deviation (in red) or option, so the buyer could see exactly what the base scope covers.

5. 5. Technical clarification rounds

   • Lead time, factory acceptance test, filter set and spare parts were clarified point by point.
   • Comply: hazardous-area approach with Ex-certified components; factory acceptance test free of charge, witnessed by the buyer or end user; six consecutive starts set in the controller.
   • Deviation kept visible: dry exhaust manifold instead of water-cooled (exhaust insulation added), salient-pole alternator with IC 01 cooling and grease-lubricated bearings, standard turbocharger surface temperature.
   • To be confirmed: ISO 3046-4 class M3 governing, transient limits in the block-load test, 7 h + 1 h temperature-rise test.

6. 6. Optional items identified and priced

   • 29 option items were extracted from the datasheet in four groups: engine and fuel, alternator, enclosure, control and switchgear.
   • Each item was priced individually and then integrated into one all-inclusive scope at the buyer's request; amounts are not published.

7. 7. Customer briefing: revised datasheet Rev.1

   • Rev.1 changed 56 lines, each marked in the revision column; all 29 former option lines now marked as included.
   • Remaining deviations stay in red, so the evaluation team sees them openly.
   • The datasheet was returned in the customer's original Excel format plus a signed and stamped PDF.

8. 8. Delivery and logistics planning

   • Lead time as stated in the offer: 3–4 weeks after order confirmation, plus 1 week reserve for imported option items.
   • Shipping data prepared: approx. 10,800 kg net, 4,900 × 2,500 × 3,500 mm, approx. 42.9 m³; certificate of origin.

9. 9. Document package

   • Offer, datasheet in the customer's format (signed), catalogue pages, alternator manufacturer's datasheet, factory load-test report sample, warranty terms, start-up and handover form, service forms and operating guide.

Our work

Requirement analysis · Model selection and sizing

• Every one of the 239 datasheet lines was answered in the customer's last column.
• Prime rating compared with the requirement: 1125 kVA prime on the base model, 1350 kVA prime on the alternative model.
• +50 °C ambient and −20 °C cold start checked: jacket water heater and lube oil heater added; high-ambient rating to be confirmed with the engine manufacturer.
• Fuel autonomy checked against datasheet consumption: base tank on the skid covers at least 8 hours at 100 % prime.
• Items outside the base scope grouped into 29 options in four groups.

Point-by-point compliance table

Options identified and priced

• Air shut-off valve
• Separate fuel shut-off valve
• Double-sheathed braided fuel lines
• Lube oil mist eliminator
• Oil maintainer with 100 L tank
• Continuous oil level monitoring (alarm and trip)
• Lube oil heater
• Jacket water heater
• Exhaust thermal insulation (surface ≤200 °C)
• Spark / flame arrester, Zone 2 certified
• PMG + MX321 AVR
• Marine double-dip varnish (winding and exciter)
• Alternator inlet and outlet filters with dust filter
• Stator winding PT100 RTDs
• Alternator space heater
• IP55 electrical equipment
• C5-M offshore marine coating
• IP55 enclosure with motorised louvres
• Filtered air inlet louvres
• Enclosure space heater
• Enclosure alarm system
• Fire and gas detection with beacon, sounder and flash lights
• External alarm beacon and sounder
• Anchor bolts, nuts and washers
• 4-pole motorised output breaker with LSIG protection
• Woodward easYgen controller
• Synchronising for parallel operation
• External synchronising, voltage bias, speed bias and 24 V DC terminals
• Individually Ex-certified components (ATEX/IECEx)

Documents prepared · Offer package

• Commercial offer (line-item structure; prices not published here)
• Revised datasheet (changed lines marked, signed and stamped, in the customer’s Excel format)
• Model datasheet
• Catalogue pages
• Alternator datasheet
• Factory load-test report (sample)
• Warranty terms document
• Start-up and handover form
• Maintenance and service forms
• Operating and maintenance manual

• Factory load-test report (sample)
• Warranty terms document
• Start-up and handover form

• Datasheet returned in the customer's original Excel format, last column completed, plus a signed and stamped PDF.
• Deviations highlighted in red; every line marked as comply, deviation, included or to be confirmed.
• A separate signed datasheet was prepared for the 1350 kVA prime alternative.

Proposed solution

Values are taken from the model’s datasheet; the full datasheet and catalogue page are on the model page.

Offered configuration

• Woodward easYgen controller with synchronising for island-mode parallel operation
• PMG + MX321 AVR, marine double-dip varnish, PT100 stator RTDs, alternator space heater
• IP55 canopy with motorised and filtered louvres, C5-M offshore coating
• Fire and gas detection, Zone 2 spark arrester, air and fuel shut-off valves
• 4-pole motorised output breaker with LSIG protection

Alternative configurations

• TRX P ST 1500 – Perkins 4012-46TWG3A, 1,500 kVA standby / 1,350 kVA prime

Packing, shipping and export documents

• Lead time as stated in the offer: 3–4 weeks after order confirmation, plus 1 week reserve for imported option items.
• Shipping data: approx. 10,800 kg net, 4,900 × 2,500 × 3,500 mm, approx. 42.9 m³.
• Export documents: commercial invoice, packing list, certificate of origin, factory test report.