A generator set specification for tender needs seven technical sections: scope and duty rating, engine requirements, alternator requirements, electrical performance, control and protection, fuel and noise limits, and testing with commercial terms. Get those seven right and bidders can price comparable machines. Get them wrong and you’ll collect bids you can’t compare, or worse, award a generator that can’t do the job.
We’ve sat on both sides of this document. As a manufacturer, our engineering team responds to generator tenders every month, from 20 kVA municipal units to 1,250 kVA data center packages.
We see the same specification mistakes repeated across countries and industries. Some cost buyers 15-20% on price. Others don’t surface until the generator fails its first real outage.
This guide walks through each section of a tender specification, the parameters that matter in each, and the five mistakes that ruin otherwise solid procurement exercises. If you’re a supplier preparing a bid, the final section covers what evaluators actually check.
Основные выводы
- A complete genset tender specification has 7 sections: duty rating, engine, alternator, electrical performance, controls, fuel/noise, and testing plus commercial terms.
- The single most damaging error is specifying a standby (ESP) rating for a prime-duty application. Standby sets are designed for roughly 200 hours per year with no overload capability.
- Real tenders require 10% overload for 1 hour in 12, AVR regulation between ±0.25% and ±2.5%, and site testing of 6 hours at full load plus 1 hour at 110%.
- Evaluation is almost always two-stage: a pass/fail technical compliance gate, then weighted scoring with a 70-75% minimum before price is even opened.
- Never name a single engine brand without adding “or equivalent.” Brand-locking shrinks competition and inflates prices.
What Is a Generator Set Tender Specification?
A generator set tender specification is the technical section of a procurement document that defines exactly what the buyer wants bidders to supply: power rating, engine and alternator requirements, performance standards, testing obligations, and warranty terms. It’s the document supplier’s price against, and it becomes part of the contract.
Three documents get confused here. The buyer writes the tender specification before bidding. The данные is what each supplier submits in response, describing their actual machine. The заказ на покупку locks the winning datasheet into a contract.
This guide covers the first one. If you’re on the other side trying to read the spec sheets suppliers send back, our guide to чтение технических характеристик генераторной установки covers that document.
Who writes the tender spec? Usually, a procurement team works with a consulting engineer or an experienced facilities manager. Who reads it? Every bidder’s sales and engineering teams, line by line.
The clearer the document, the tighter and more comparable the bids you’ll receive.
The 7 Sections Every Genset Tender Specification Needs
The structure below comes from patterns across real public tenders: an 850 kVA standby set for a Pakistani university, a 650 kVA silent unit for an Indian research institute, a 1,250 kVA prime-rated set for a South African municipality, and emergency generator packages from Canada and the Philippines. Different sizes, different continents, same seven sections.
1. Scope and Duty Rating
Open with the scope of work: supply only, or supply plus installation, testing, and commissioning. Most public tenders expect the full turnkey scope.
Then state the duty rating in ISO 8528-1 terms. This is where tenders go wrong most often. A standby (ESP) rating suits emergency backup with a reliable grid, roughly 200 hours per year. A prime (PRP) rating suits sites where the generator is the main power source, with unlimited hours and a 10% overload allowance. Continuous (COP) is for constant-load, 24/7 operation.
If you’re unsure which duty your application needs, our breakdown of standby vs prime vs continuous generator ratings walks through the decision. Specify the rating explicitly, for example: “1,000 kVA prime (PRP) at 0.8 power factor, site conditions 40°C, 1,000 m altitude.” Bidders price standby and prime machines differently. Leave it ambiguous and you’ll receive both.
2. Engine Requirements
The engine section of real tenders converges on a short list of parameters:
- Тип: 4-stroke diesel, turbocharged, water-cooled with radiator
- Скорость: 1,500 rpm for 50 Hz, 1,800 rpm for 60 Hz
- Начало: electric start with 24V batteries and charger
- Губернатор: electronic or automatic, with over- and under-speed protection
- Перегрузка: 10% for 1 hour in any 12-hour period (prime-rated sets)
- Окружающая среда: tropicalized for your site conditions, often 50°C and 95% relative humidity in Middle East and Asian tenders
Resist the urge to over-specify. Locking displacement, cylinder count, or a specific engine family removes competition without adding reliability. Specify performance and standards, not part numbers.
3. Alternator Requirements
The alternator half of the genset determines electrical quality. Across the tenders we reviewed, the dominant specification is:
- Тип: brushless, self-excited, self-regulated with AVR
- Изоляция: Class H (Class F appears in lighter-duty tenders)
- Protection: IP23 minimum for indoor installations
- Регулировка напряжения: ±0.25% to ±2.5%, depending on how critical the load is
- Дополнительные сервисы: anti-condensation heaters in the stator windings for humid sites
A hospital or data center should sit at the ±0.25-1% end with Class H insulation. A construction-site standby set can live with ±2.5%. Match the spec to the load, not to the most expensive datasheet you’ve seen.
4. Electrical and Performance Parameters
State the output plainly: 400/415V or 480V, 3-phase, 50 or 60 Hz, at 0.8 power factor. If your facility’s load profile suggests a different power factor, say so, because kVA and kW diverge as power factor drops. Our сравнение кВА и кВт explains the 0.8 convention and when it breaks.
For anything beyond basic backup, add a transient performance requirement. ISO 8528-5 performance classes (G1 through G4) give you a standard vocabulary. G2 suits general commercial loads. G3 suits connected equipment like data centers and medical imaging.
Referencing a class is cleaner than inventing your own voltage-dip numbers, and every serious manufacturer tests against it.
5. Control, Protection, and Monitoring
Modern tenders specify a microprocessor-based controller with auto mains failure (AMF) logic as standard. The monitoring list is remarkably consistent: voltage and current per phase, frequency, kW, kVA, power factor, engine hours, oil pressure, coolant temperature, and fuel level.
The protection shutdown list matters more than the display list. Require automatic shutdown on low oil pressure, high coolant temperature, over- and under-speed, over- and under-voltage, and emergency stop. For facility integration, specify RS485 or BACnet outputs plus potential-free contacts for the building management system. Remote monitoring with SMS or email alerts is now standard on anything above 100 kVA.
6. Fuel, Noise, and Installation Requirements
Size the fuel tank by runtime, not litres. Tenders specify either 8-10 hours at full load for standby sets or 24 hours for critical infrastructure, sometimes with a UL 142 double-wall tank requirement in North America. A runtime requirement lets bidders optimize tank geometry for their machine while you keep the outcome fixed.
Noise limits need a distance to mean anything. “Silent type” is not a specification. “75 dB(A) at 1 meter” is. So is “65 dB(A) at 7 meters” for residential-adjacent sites.
Add local emissions compliance (CPCB norms in India, EPA tiers in the US, EU Stage V in Europe) and installation requirements like vibration isolators, exhaust routing, and earthing.
7. Testing, Documentation, and Commercial Terms
Testing clauses separate paper specifications from delivered performance. Common requirements include a factory acceptance test (often an 8-hour run), site testing of 6 hours at full load plus 1 hour at 110% overload, insulation resistance of at least 1 MΩ, and a load-bank test where site load isn’t available.
Commercial terms complete the picture: warranty of 1 year or 1,000-2,000 running hours, spare parts availability for 10 years, after-sales response time, and a compliance statement format for bidders to follow. That last item is underrated. Requiring bidders to answer every spec line with “Comply / Not Comply” plus a page reference to their datasheet makes evaluation dramatically faster.
Generator Tender Specification Checklist
Use this table as a skeleton for your document. The “typical requirement” column reflects patterns from real public tenders, not ideals.
| Раздел | Ключевые параметры | Типичное требование |
|---|---|---|
| Рейтинг долга | kVA/kW, rating type, power factor | Prime (PRP) or standby (ESP) per ISO 8528-1, 0.8 PF |
| Двигатель | Type, speed, starting, overload | 4-stroke diesel, 1,500/1,800 rpm, 10% overload 1 hr in 12 |
| Генератор | Insulation, protection, regulation | Class H, IP23, AVR ±0.25-2.5% |
| Electrical | Voltage, frequency, transient class | 400/415V 3-phase 50 Hz, ISO 8528 G2-G3 |
| Управляет тем, | Controller, monitoring, shutdowns | AMF controller, BMS output, 6+ auto shutdowns |
| Fuel & noise | Runtime, dB(A), emissions | 8-24 hr tank, 75 dB(A) @ 1 m, local norms |
| Тестирование | FAT, site test, load bank | 8-hr FAT; 6 hr full load + 1 hr at 110% on site |
| Коммерческий интерьер | Warranty, spares, compliance format | 1 yr / 1,000-2,000 hr, 10-yr spares, page-referenced compliance table |
The 5 Mistakes That Ruin Generator Tenders
Mistake 1: Specifying standby for a prime-duty job
Grace, a facilities consultant in East Africa, wrote the tender for a regional hospital’s backup power in 2023. The grid there fails several times a week, and the generator routinely runs 4-6 hours a day. She copied a previous tender that specified “standby rated, 500 kVA.” Within 18 months the winning set had logged over 3,000 hours on a rating designed for 200 hours a year, and the engine needed a top overhaul years early.
The re-tender, this time prime-rated, cost the hospital a second procurement cycle and a warranty dispute in between. One word in Section 1 caused all of it.
Mistake 2: Brand-locking the specification
Samuel manages procurement for a municipal utility. His 2024 generator tender named one engine brand and one alternator brand with no “or equivalent” clause, because that’s what the maintenance team already stocked parts for. He received exactly two bids, both 15-20% above budget.
The re-issued tender kept the performance requirements identical but allowed equivalent engines meeting the same specs. Five bids came back, and the winner landed under budget with the same warranty. Performance-based specifications get you competition. Brand names get you a monopoly.
Mistake 3: No compliance statement format
Without a structured compliance table, every bidder answers the spec in a different format. One submits a glossy brochure, another a 40-page datasheet pack, a third a letter saying “we meet all requirements.” Evaluators can’t compare them, clarification rounds multiply, and the evaluation stretches from two weeks to three months. Mandate the format: every parameter, marked Comply or Not Comply, with a datasheet page reference.
Mistake 4: Underspecifying testing
A specification without test requirements is a promise, not a contract. Require the factory test, the site load test, and the overload hour. If a bidder’s machine can’t sustain 110% for an hour, you want to learn that on commissioning day, not during a real outage.
Mistake 5: Omitting after-sales terms
The cheapest compliant bid often wins. If your tender says nothing about spare availability, service response time, or warranty scope, the lowest price can hide the most expensive ownership. Ten-year spares support and a defined response SLA (many public tenders require breakdown attendance within 4-24 hours) cost bidders money to promise, which is exactly why you want them in writing.
How Generator Tenders Are Evaluated
Understanding evaluation helps you write a better spec, and if you’re a bidder, it tells you where bids die.
Stage 1: The compliance gate
Most public tenders assess mandatory criteria on a pass/fail basis first. Technical datasheets submitted? OEM authorization letters? Compliance table complete? Experience thresholds met, often 2-5 years plus several similar completed projects with certificates?
Any “no” ends the bid. No amount of low pricing rescues a technically disqualified offer.
Stage 2: Weighted scoring
Bids that pass the gate get scored on weighted criteria: technical merit, methodology, key personnel, delivery timeline, warranty, and after-sales support. A minimum score of 70-75% is common before the financial envelope is opened. Only then does price decide, and the award typically goes to the lowest-priced technically compliant bidder.
The practical lesson for buyers: everything you care about must live in the written specification, because the evaluation can only test what’s written. The lesson for suppliers: compliance completeness beats persuasion. Evaluators can’t credit what isn’t documented.
For Suppliers: How to Respond Without Getting Disqualified
This section is for the sales engineers on the other side of the table. We respond to these documents ourselves, and the failure modes are predictable.
Wei, a bid engineer on our side of the industry, lost a tender his team should have won in 2022. Their generator met every technical line. But the compliance table listed “Comply” for 60 parameters without a single page reference, and the evaluation committee’s rules said unreferenced claims couldn’t be verified. A competitor with a weaker machine but page-referenced datasheets passed the gate.
Wei’s team hasn’t submitted a compliance statement with page references since.
Three rules follow from that experience:
- Reference every claim. Comply plus page number plus datasheet document ID. Evaluators check spot samples, and unverifiable claims score as non-compliant.
- Declare deviations honestly. A stated deviation with an engineering justification often survives. A hidden one discovered at commissioning becomes a contract dispute.
- Submit every mandatory document. OEM authorization, experience certificates, test reports. Check the mandatory list twice; it ends more bids than technical weakness does.
Buyers benefit from strict compliance too. It filters out suppliers who can’t document their claims, which correlates strongly with suppliers who can’t support their machines.
Часто задаваемые вопросы
What should a generator tender specification include?
Seven sections: scope and duty rating, engine requirements, alternator requirements, electrical and transient performance, control and protection systems, fuel tank and noise limits, and testing plus commercial terms. Include a mandatory compliance statement format so bids can be compared line by line.
Should a tender specify a prime or standby rating?
Match the rating to the actual annual hours. Choose standby (ESP) for emergency backup on a reliable grid, around 200 hours per year. Choose prime (PRP) when the generator is the main power source or runs regularly, since it allows unlimited hours plus 10% overload. When in doubt, specify prime.
Is it acceptable to name a specific engine brand in a tender?
Yes, but always add “or equivalent” with the performance criteria defined. Naming a brand alone restricts competition and typically raises bid prices by 15-20%. If your maintenance team stocks parts for one brand, state it as a preference with justification, not a hard lock.
What warranty should a generator tender require?
The industry standard in public tenders is 12 months or 1,000-2,000 running hours, whichever comes first. For critical applications, spare parts availability for 10 years and a defined service response time, commonly 4-24 hours depending on site criticality.
How are generator tenders evaluated?
Almost universally in two stages. First, a pass/fail gate on mandatory criteria like datasheets, OEM authorization, and experience. Second, weighted scoring of surviving bids, usually requiring 70-75% minimum before financial evaluation. The award typically goes to the lowest-priced technically compliant bidder.
What testing should a genset tender require?
At minimum: a factory acceptance test (commonly 8 hours), site testing of 6 hours at full load plus 1 hour at 110% overload, insulation resistance of at least 1 MΩ, and functional tests of all protections and the AMF sequence. Add a load-bank test when sufficient site load isn’t available at commissioning.
Conclusion: Write the Spec You’d Want to Bid Against
A generator set specification for tender succeeds when every bidder can price the same machine and every evaluator can compare the bids line by line. That comes down to seven complete sections, a mandatory compliance format, and performance-based language instead of brand names.
The mistakes are equally consistent: standby ratings on prime-duty sites, brand-locked engines, missing test clauses, and after-sales terms left silent. Each one is cheap to fix at the drafting stage and expensive to discover after the award.
If you’re preparing a tender now, our engineering team reviews specifications and responds to RFQs for промышленные дизель-генераторные установки from 20 kVA to 3,000 kW. Send us your specification and we’ll return a compliant, page-referenced quotation, the same standard this guide teaches you to demand. A well-written tender is the first component of a reliable power system.
