Compare prime, standby, and continuous generator ratings by matching the site duty, issuer rules, quoted set, power data, and source documents on one basis.
Standby, prime, and continuous ratings describe different duty proposals; they are not quality grades or fixed conversions. First freeze the source role, load pattern, run plan, power system, and site conditions, then require each supplier to map that same duty-profile revision to a named rating rule and the exact offered set. Compare price only after the mapping and source files agree.
Freeze the duty profile before choosing a rating
A seller can map a clear site duty to a stated rating rule. A buyer cannot work backward from a preferred label to a vague job without risking a false match.
Send one duty-profile sheet to every bidder. Give it a revision code. If you later change the job, issue a new revision so no one works from an old brief.
| Buyer field | What to state | Why it matters |
|---|---|---|
| Source role | Backup, emergency, main, hire, base load, or another clear role. | A site label such as "remote" doesn't define the duty. |
| Normal source | Say if a utility or other source is normally on. | This shows if the set runs only after another source fails. |
| Load type | Constant, variable, mixed, step load, or still open. | The seller can match the load to its own rule. |
| Run plan | Events, run pattern, time of year, and expected use. | This replaces a guessed hour limit with the real need. |
| Power data | kW or kVA basis, voltage, frequency, phase, and power factor. | It keeps unlike power systems out of one price table. |
| Site data | Altitude, heat, room or enclosure, and agreed site points. | Site output stays tied to the same offer. |
| Project rules | Client, adviser, utility, insurer, and local authority needs. | A sales label can't grant outside approval. |
Use the industrial generator sizing guide to build the load list. Record high-altitude and hot-site inputs with the site-rating input method. These steps help define the job. They don't pick a duty rating for you.
Lock the issuer, definition, and source document
Each quoted term needs a named issuer and a source you can trace. A bare word such as "prime" or "standby" is not enough, and one maker's definition cannot close another maker's offer.
Ask the seller to copy the exact term and short form from the source document. The return should also state:
- Who owns or issues the rating rule.
- The document title, date or revision, and page or section.
- A named framework, such as ISO 8528-1, only if the issuer cites it.
- The load terms, test or site basis, service basis, limits, and exclusions.
- Any other rating as a separate quote line with its own terms.
Why be this strict? Makers don't all present rating families in the same way. Cummins gives its explanation of generator-set ratings linked to ISO terms. Caterpillar shows more rating names than the three broad groups.
Use the current rule from the issuer of the set on your quote. Don't copy one maker's limits to another maker's offer.
Duty is not the same as rated, peak, or surge power. If a quote mixes those output terms into the duty claim, use the rated-versus-peak check before you compare it.
Use the three families only to route the review
At a high level, standby points to backup use. Prime often points to a variable-load basis. Continuous points to a constant-load basis. Use those descriptions to select the next question, not to approve a rating.
Those short notes don't set common hour limits, average loads, overload rights, or price bands. They also don't make the ratings easy to swap.
| Review point | Standby proposal | Prime proposal | Continuous proposal |
|---|---|---|---|
| Job to map | A stated backup or emergency role. | A stated main, hire, remote, or variable-load role. | A stated constant or base-load role. |
| Seller must give | Exact term, short form, issuer, rule, terms, and limits. | Exact term, short form, issuer, rule, terms, and limits. | Exact term, short form, issuer, rule, terms, and limits. |
| Load wording | Copy it from the source rule. | Copy it from the source rule. | Copy it from the source rule. |
| Time and service | Use the exact source only. | Use the exact source only. | Use the exact source only. |
| Buyer test | Does it match the stated job? | Does it match the stated job? | Does it match the stated job? |
A quote may use other names. It may say limited-time, emergency standby, mission-critical standby, or base load. Keep the seller's exact term. Don't squeeze it into a broad column or turn it into another rating with a stock percentage.
Tie the rating to the exact quoted set
A rating becomes comparable only when it belongs to the set you may buy. An engine sheet, alternator curve, family brochure, or dealer table proves only what that file names.
Match the same item across the quote and its source files:
- Generator-set brand, model, build, and quote revision.
- Engine and alternator models, when the seller gives them.
- Control panel, cooling, open or enclosed build, fuel, and options.
- Frequency, voltage, phase, power factor, and stated kW or kVA.
- Data sheet or submittal title, revision or date, and page.
- Load terms, site or test basis, service basis, limits, and exceptions.
The number alone is not a match. A file for another frequency, engine, alternator, enclosure, cooling pack, or duty rule belongs outside the like-for-like price table.
If supplier-selected controls, cooling, enclosure, documentation, or branding changes the rating presentation or its limits, attach the frozen duty profile and issuer-source mapping to the BEAR OEM and private-label project review.
Compare every supplier on one return sheet
Do not start with price. First place each supplier's answer in the same return sheet and preserve any declared exception to the buyer input.
| Return block | Exact seller response | Buyer result |
|---|---|---|
| Quote ID | Number, revision, date, seller name, and contact. | You can name the live offer. |
| Buyer input | Duty-profile ID plus each stated change or exception. | The answer maps to the same job. |
| Rating claim | Exact label, short form, kW or kVA, power factor when used, and issuer. | The figure has a named basis. |
| Rule proof | Source title, date or revision, page or section, and named framework if claimed. | You can trace the rule. |
| Terms | Load wording, site or test basis, service basis, limits, and exclusions. | The limits stay with the figure. |
| Set ID | Set, engine, alternator, control, cooling, enclosure, fuel, frequency, voltage, phase, and options. | The proof maps to the priced build. |
| Other option | Its own line, reason, proof, price, and terms. | No silent swap took place. |
| Seller sign-off | A clear note that the rating and files apply to the quoted build. | The answer is ready to sort. |
Now give each offer one status:
COMPARABLE: all core fields share one basis.CONDITIONAL: one named input is open, but it doesn't yet change the core match.RETURN: the seller can fix missing rule, term, or set proof.STOP: a major mismatch, file clash, or outside approval blocks release.
These are buying controls. They aren't engineering approval, legal approval, or a model choice.
Return fixable gaps and stop material mismatches
Missing proof and a bad duty match are not the same problem. Return a fixable document or identity gap. Stop an offer that does not fit the stated job or cannot meet an outside approval rule.
An aligned return names the issuer and rule revision, ties every source to the exact set, makes terms and exceptions easy to find, and puts any alternative on its own quote line.
Return a quote when it has only a bare label or a family brochure. Do the same for an unknown file date, proof for one part only, mixed power systems, or a hidden change of rating basis.
Stop before you release a purchase order when:
- The proposed duty doesn't match the buyer's run profile, and the gap is still open.
- The quote, data sheet, submittal, model ID, and rating claim don't agree.
- Someone used a stock factor or made-up run rule to convert one rating to another.
- A limit or service term may change the planned use, but no one has accepted it.
- A client, adviser, utility, insurer, or authority still has to accept the basis.
- The seller can't tie the rating to the exact set on the quote.
Send one controlled RFQ and return package
Give every seller the same duty-profile revision and the same reply fields. Require each return to cite the buyer revision it used and list every departure. That makes later changes easy to spot.
Your pack should include:
- Country or state, end use, and normal source setup.
- Source role, load type, run plan, and expected use.
- kW or kVA basis, voltage, frequency, phase, and power factor.
- Altitude, heat basis, room or enclosure, and other set site points.
- Required set build plus fixed technical and trade terms.
- The rating label, issuer, source title, revision, page, terms, service basis, limits, and exact set ID to return.
- Any client, adviser, utility, insurer, local rule, or approval point the seller must answer.
- Quote due date and the full file list.
For a first BEAR quote, send Miya the duty profile, power system, site data, target market, build needs, order size, and return-file list. Ask BEAR to return the exact rating term, issuer, rule revision, limits, offered build, source-file IDs, exceptions, and open-item owners. Keep the duty rating and model open until that exact-set evidence is available.
