Short answer: “10 kW, please quote” is not yet an inverter RFQ. On our review sheet, the first boxes are country, measured AC voltage, phase and frequency. Then come the string calculation, load notes, battery, backup circuit and approval rule. The kW box is halfway down the page. That order feels slower for five minutes and usually saves days later.
That distinction matters to distributors, EPC contractors and project developers. Two products carrying the same “10 kW” label may belong to different electrical architectures. One may be a single-phase grid-tied unit. Another may be a 48 V battery inverter designed for an off grid solar system. A third may be a three-phase hybrid inverter with a high-voltage battery bus. They are not interchangeable, and a price comparison that ignores the architecture is not a comparison at all.
This guide gives B2B buyers a repeatable method for specifying, comparing, sampling and accepting solar inverters. It is written for people who will have to defend the purchase after delivery: procurement managers, electrical engineers, distributors, installers, developers and owners. It also explains what THLinkSolar can document now, what must be confirmed for a particular model and market, and what information a supplier needs before preparing a responsible quotation.
Send Your Voltage, Phase and Project Load for an Inverter Recommendation
1.The procurement problem behind the simple phrase “solar inverter”
An inverter has four neighbors: PV strings, the grid or generator, a battery when storage is used, and the loads. A wrong assumption at any boundary shows up somewhere else. The installer sees a trip. The owner sees lost production. The distributor receives a “defective unit” claim. More than once, the culprit turns out to be a string outside the hot-weather MPPT window or a battery protocol that was never agreed.
Here is a real-world style of inquiry: “50 pieces, 8 kW hybrid.” Useful quantity; almost nothing else. Is the service 120/240 V split phase, 230 V single phase or 400 V three phase? Is it 50 or 60 Hz? Can the customer export? Is the battery a 48 V stack or a high-voltage rack? One irrigation pump can change the surge discussion. The missing country matters too, because the paperwork and grid settings start there.
A serious solar inverter supplier should slow that inquiry down long enough to remove ambiguity. Speed is useful after the electrical basis is clear. Before that point, a fast number can simply be a fast route to the wrong unit.
What a buyer is really procuring
- The right circuit role. The unit must suit the way PV, grid, generator, battery and backup loads are actually connected.
- A usable window. Nominal kW matters, but so do DC voltage, current, MPPT range and AC output limits.
- Predictable behavior. Protection, controls and communications should react as the project design expects.
- Market evidence. A named model—not a similar family—needs the documents required at the destination.
- A handover path. The local installer needs a manual, settings record and somebody to call with a useful log file.
- The whole box. Record model suffix, firmware, meters, CTs, dongles, connectors, packing and claim route.
We put one extra column beside unit price: “work created elsewhere.” A bargain disappears quickly if the electrician must rebuild a panel, the battery voltage is wrong, a meter was omitted or commissioning needs two return visits.
2. Start with topology: on-grid, off-grid or hybrid
The first selection is functional. A grid-tied inverter converts PV power and operates with a live utility reference. An off-grid inverter forms an AC supply for local loads, typically using a battery and sometimes a generator. A hybrid inverter coordinates more than one source and may provide both grid interaction and backup output. The labels sound familiar, but buyers should read the operating diagram rather than depend on the label alone.
| Architecture | Primary job | Questions that decide suitability | Typical B2B risk |
|---|---|---|---|
| On-grid | Convert PV and synchronize with utility | Grid code, export rule, AC voltage, MPPT window, monitoring | Correct power rating but wrong interconnection settings or documentation |
| Off-grid | Form a stable local AC supply | Peak loads, surge, battery voltage, generator input, autonomy | Sizing from average energy while ignoring motor starting demand |
| Hybrid | Coordinate PV, grid, battery and backup loads | Battery protocol, backup circuit, transfer behavior, export control | Assuming every battery and every hybrid inverter communicate |
Do not infer backup capability from the word “hybrid.” Ask for the terminal diagram, supported operating modes, backup-output rating, overload duration, transfer behavior and black-start procedure. If a project depends on uninterrupted operation of a cold room, pump controller or process line, the buyer should define the acceptable interruption and the priority-load circuit. “Has backup” is not an acceptance criterion.
3. Phase and voltage come before model selection
Phase mistakes are among the most expensive errors because they touch switchboards, protection and local load distribution. The buyer should record the voltage measured line-to-neutral and line-to-line, the service arrangement, earthing system where relevant, and utility frequency.A photograph of the nameplate and a single-line diagram are more useful than a message saying “standard voltage.”
Single phase
Single-phase inverters are familiar on homes and light-commercial sites. In the current THLinkSolar catalog, TP-GTI runs from 1 kW to 10 kW. Reading across the individual model columns—not the family heading—shows a 450 V or 500 V maximum DC input, one or two trackers, and listed peak conversion efficiency of roughly 97.3% to 98.1%. Keep the model column with the quote. A number taken from the 10 kW column does not automatically belong to the 3 kW unit or to next year’s revision.
Split phase
A split-phase service is not merely “single phase at a different voltage.” It normally supplies two line conductors and a neutral, allowing line-to-neutral and line-to-line loads. For a project with mixed 120 V and 240 V loads, the engineer must consider load balance, neutral current, backup-panel arrangement and generator compatibility. THLinkSolar’s TP-SPI catalog range includes 8 kW and 10 kW split-phase inverter models using a nominal 48 V battery platform, two MPPT trackers and a documented PV MPPT window of 125–425 V. Peak output is shown as 16 kW or 20 kW for the respective models, but the permitted duration and test conditions must be taken from the model manual before sizing a motor or compressor.
Three phase
Three-phase projects require more than a 400 V label. Confirm whether a neutral is needed, the allowable phase imbalance, the grid connection arrangement, output current and any site transformer assumptions.The TP-TL on-grid family is documented from 4 kW to 15 kW, with 1000 V maximum DC input, a 160–850 V MPPT range and maximum efficiency listed at roughly 98.0–98.4% depending on model. The TP-ESS/TP-EPH hybrid family is documented from 4 kW to 12 kW with a 130–700 V battery range and two MPPT trackers. These two families solve different problems even when their AC power ratings overlap.
For a distributor, phase segmentation should also be a stock-planning decision. A mixed container of models based on guessed regional demand can create slow-moving inventory. Use actual installer requests, utility service data and country-specific model approvals to build the assortment.
4. Translate the PV array into an inverter input window
PV-side compatibility is governed by voltage and current under real conditions, not by a simple DC-to-AC power ratio. The design team should calculate maximum open-circuit voltage at the lowest expected cell temperature, minimum operating voltage at high cell temperature, string current, parallel-string current and the distribution of strings among MPPT channels.
A useful review sheet includes module model, Voc, Vmp, Isc, Imp, temperature coefficients, modules per string, strings per MPPT, design minimum temperature and design maximum cell temperature. It should show the formula and the source of every input. If a proposal only says “twenty 550 W panels,” the electrical review is unfinished.
Cold-weather maximum voltage
Module open-circuit voltage rises as cells get colder.The maximum corrected string Voc must remain below the inverter’s absolute DC limit with an appropriate design margin and in accordance with local rules. A string that looks safe at standard test conditions can exceed the limit on a clear cold morning. This is a safety and equipment-survival question, not an energy-yield preference.
Hot-weather MPPT voltage
Operating voltage falls when cells are hot. At the highest expected cell temperature, the string should still operate within the MPPT range. In hot climates, using ambient temperature alone can be misleading because module cells operate well above ambient under strong irradiance. If the string falls below the MPPT window, the system may start late, stop early or track poorly.
Current per input
Modern high-power modules can challenge inverter input-current limits even when voltage is acceptable. Confirm maximum operating current and short-circuit current per MPPT or per string input. Do not assume that two connectors always mean two independent trackers. Connector count, string-input count and MPPT count are separate specifications.
When procuring modules and inverters together, a qualified solar panel manufacturer should provide traceable module electrical data, while a buyer seeking solar panels wholesale should request the final packing list and the exact module revision before freezing string design.Substituting a “similar wattage” module after engineering approval can change current, voltage, dimensions and container loading.
5. Power rating: distinguish continuous output, apparent power and overload
Inverter names are often built around a headline power value, but the datasheet may contain rated active power, maximum active power, apparent power, output current and a temperature-dependent derating curve. Procurement should identify which value the tender requires and at what ambient condition.
For grid-tied systems, the engineer may intentionally select a DC array larger than the inverter AC rating. The ratio depends on climate, orientation, utility export constraints, energy model and economic objective. A high ratio can improve utilization in weak irradiance but increase clipping at high irradiance. Neither “oversize as much as possible” nor “DC must equal AC” is a universal rule.
For backup systems, continuous kW is only part of the load problem. Motors, pumps, compressors and transformers can demand a high starting current. Ask for starting method, locked-rotor or inrush data, number of starts per hour and whether loads can start sequentially. A 3 kW running load may require a much larger inverter if it includes a direct-on-line motor. Conversely, a variable-frequency drive may reduce starting demand but introduce its own compatibility and harmonic considerations.
A practical load table
| Load | Quantity | Running W each | Starting method / surge | Priority | Hours / duty cycle |
|---|---|---|---|---|---|
| Cold-room compressor | Buyer input | Nameplate | DOL, soft starter or VFD | Critical | Measured profile preferred |
| Water pump | Buyer input | Nameplate | Record start current | Shiftable or critical | Seasonal schedule |
| Lighting and controls | Buyer input | Measured | Low surge, verify drivers | Critical | Operating hours |
This table is deliberately incomplete. A supplier should not invent the missing values. The buyer or site engineer should provide them, and the quotation should state the assumptions used when measured data are unavailable.
6. Efficiency figures need context
Maximum efficiency is useful for comparing technology, but it is not an annual energy prediction. Real operation moves through a range of input voltages, power levels and temperatures. Wiring, transformers, clipping, standby consumption, battery conversion and auxiliary loads also affect delivered energy.
Circle the word beside the efficiency number. “Maximum,” “weighted,” and a result at one test point answer different questions. On a hybrid unit, write the energy path in the margin: PV→AC, battery→AC, AC→battery, or PV→battery. If the path is missing, the percentage is not ready for the comparison sheet.
For a bankable project, use an energy model with documented assumptions. For distribution purchasing, use efficiency together with operating temperature, protection degree, service access, monitoring and return data. Chasing a fraction of a percentage point while ignoring a poor MPPT match is a familiar procurement mistake.
7. Grid-code evidence is model-specific and market-specific
A declaration that a company “has certificates” is not enough. The buyer should verify the certificate holder, exact model family, standard edition, country annex where applicable, issue date, validity, laboratory or certification body, and whether the document covers the firmware or settings supplied.
For a US job, one line on the engineer’s checklist will usually point to IEEE 1547. The standard reaches well beyond “the inverter synchronizes”: it covers behavior during abnormal grid conditions, power quality, islanding, interoperability and test requirements. Start with the official IEEE Standards Association description of IEEE 1547, then ask the serving utility what it actually accepts. Important: this link explains a standard. It is not a certificate for any THLinkSolar model.
Other markets use different grid rules and local adoption paths. The RFQ should name the country, utility and tender requirement rather than ask vaguely for “international certification.” If the buyer cannot identify the rule, the local electrical consultant or authority having jurisdiction should confirm it before order approval.
Evidence pack to request
- Match the suffix. Put the proposed model code beside the code printed on the certificate and report.
- Write down the edition. Country annex and standard year belong in the bid file, not in somebody’s memory.
- Save the software identity. Firmware or a market parameter set can matter to the approved behavior.
- Give the installer the route. Keep the manual and the actual grid-setting steps together.
- Know who may change settings. Record the range, password or access-control method.
- Photograph the label. Model, ratings and serial format provide a quick receiving check.
THLinkSolar’s website and catalog reference multiple standards for different inverter products. Those references should be treated as a list to verify, not as permission to claim that every model carries every approval. Ask the sales and engineering team for the current document set tied to the proposed model.
8. Battery compatibility: voltage is necessary but not sufficient
A hybrid inverter and battery must agree electrically and logically. Start with nominal and operating voltage, maximum charge and discharge current, usable power and protection coordination. Then confirm communications: protocol, physical interface, approved battery list, termination, address settings and firmware versions.
THLinkSolar documents both low-voltage and high-voltage platforms. The TP-REVO HES 6 kW and 8 kW family uses a 40–58 V battery range.The TP-SPI 8 kW and 10 kW split-phase family uses a 48 V nominal battery system. By contrast, the TP-ESS/TP-EPH three-phase hybrid family is documented with a 130–700 V battery range. A battery selected for one platform cannot be assumed suitable for the other.
When using lithium batteries, request the CAN or RS485 protocol compatibility statement for the exact pair. A cable that fits is not proof of communication. If closed-loop communication is unavailable, ask whether open-loop operation is allowed, which parameters must be set manually and how charge limits will be enforced. Do not improvise this on a project that depends on warranty or regulatory approval.
THLinkSolar’s current stackable battery product page documents a 51.2 V nominal family from 5.12 kWh to 25.6 kWh, with CAN, RS485 and RS232 interfaces. The buyer should still request written pairing confirmation for the selected inverter, battery model and firmware. For a broader battery due-diligence method, review the related solar battery supplier product information and the companion battery procurement guide in this blog.
9. Backup design requires a priority-load boundary
Many commercial buildings cannot back up every circuit economically. The design should separate critical loads from noncritical loads and show the backup boundary on the single-line diagram. Refrigeration controls, communications, selected lighting and security may be critical; large resistive heaters or discretionary machinery may not be.
The inverter backup rating, battery power, cable ampacity and protective devices must all support the selected circuit. If a generator is included, document whether it feeds the inverter AC input, a separate bus, or an automatic transfer arrangement. Confirm generator voltage and frequency stability, minimum loading, start signal, warm-up time and charging limit.
“Seamless transfer” should be replaced by a number and a test. Define the permitted interruption for each critical load. Some computers tolerate a short interruption; a contactor or process controller may not. Where truly uninterrupted power is required, the project engineer should determine whether additional UPS equipment is needed.
10. Climate, enclosure and installation environment
Datasheet temperature range and enclosure rating are selection inputs, not permission to ignore the site. Inverters generate heat and require clearances. A unit installed in a small sealed cabinet, a dusty mill or direct afternoon sun may derate or age faster than the same unit in a clean shaded technical room.
Ask for these site facts
- Temperature where the inverter hangs. A city weather average is not the same as a metal room at 3 p.m.
- Air and location. Note altitude, humidity, condensation, dust, salt mist and any corrosive process gas.
- Shelter. Say indoor or outdoor, whether sun reaches the enclosure, and how warm air leaves.
- Ingress requirement. Quote the local rule and the project requirement; do not choose an IP number by habit.
- Space to fit and service it. Include wall or floor details, clearances, door swing and cable approach.
- Who can hear it. Flag a clinic room, school, office or apartment before fan noise becomes a complaint.
At altitude, lower air density can reduce cooling performance and affect insulation coordination. In hot climates, the relevant number is often the output available at the site’s sustained temperature, not the maximum output under a laboratory condition. Request a derating curve when the project operates near a limit.
11. Protection and balance-of-system coordination
An inverter does not finish the protection drawing. The engineer still has DC isolation, fusing where required, surge protection, AC breaking, residual-current protection, earthing, conductors and labels to coordinate. On a high-voltage array, I would put a red mark beside connector and isolator ratings during design review; those small parts see the same DC stress as the headline equipment.
The manual’s breaker and cable suggestions are an input. The site engineer still signs off the answer. Why? Fault level, how the cable is installed, ambient correction, grouping, voltage drop and required disconnection time can move the result. Keep the calculation with the drawing so a later installer knows which assumptions were used.
Mechanical design belongs in the same coordination process. The solar mounting system supplier needs roof type, dimensions, wind and snow basis, material requirements and array layout.The inverter engineer needs the resulting string arrangement and cable route. Treating mounting, array design and inversion as separate purchases creates interface gaps.
12. Monitoring and data ownership
Monitoring is a service tool, not only a sales feature. Before approving a platform, define who can create plants, add devices, change settings, export data and transfer ownership to the end customer. Ask what happens if the distributor account changes or the installer stops trading.
For a commercial fleet, sit down with whoever owns the network. Ask how often data are stored, how far alarm history goes back, whether local access survives an internet outage, and who approves remote updates. An API may matter; so may basic account recovery. Wi-Fi is convenient in a house. Behind a factory firewall, RS485, Ethernet, cellular or a managed gateway can be the less troublesome answer.
At handover, we save a small “device passport”: serial number, firmware, parameter file, plant owner and support contact. Six months later, that plain record usually tells a technician more than a pretty dashboard screenshot.
13. How to compare supplier quotations fairly
A bid table should normalize the technical and commercial scope. If one quote includes meters, current transformers, Wi-Fi dongles, battery cables and export-control equipment while another lists only the inverter, the unit prices are misleading.
| Comparison field | What to record | Why it changes risk or cost |
|---|---|---|
| Exact model | Full code, revision and market version | Prevents substitutions |
| Electrical scope | Voltage, phase, MPPT, battery, backup output | Confirms architecture |
| Included accessories | Meter, CT, logger, dongle, connectors, cables | Avoids incomplete delivered sets |
| Documents | Datasheet, manual, approvals, drawings, packing list | Supports permitting and commissioning |
| Commercial basis | Currency, Incoterm, port, tax, payment, validity | Makes landed-cost comparison possible |
| Service | Response path, spare policy, claim evidence, training | Changes downtime and distributor burden |
Do not fill a missing field with an assumption and then score the supplier. Mark it “not stated” and request clarification. That simple practice improves both negotiating quality and the audit trail.
14. Price, MOQ and landed cost
Inverter price depends on topology, power, voltage platform, enclosure, communication, accessories, certification scope, packaging, order volume and commercial terms. There is no responsible global price that can be published without those inputs. The same applies to MOQ and lead time: they should be confirmed against the model, configuration and production schedule at the time of quotation.
For a distributor, landed cost should include product, accessories, export packing, inland transport, freight, insurance where applicable, duty, tax, finance cost, local warehousing, expected spare stock and service labor. For an EPC, add design, approval, installation, commissioning and integration cost. The cheapest factory line can produce the highest installed cost if it leaves out required components.
For a complete commercial solar system, inverter cost should be evaluated against energy yield, serviceability and project risk rather than as an isolated percentage. The companion guide explains the assumptions behind commercial solar system cost and why a budget quote should disclose exclusions.
15. Sample order before volume order
A sample is not a ceremonial first purchase. It is a controlled engineering and commercial test. Agree on the sample model, firmware, accessories and acceptance plan before payment. If the later production order will use a different market version or firmware, the sample result may not transfer.
Suggested sample tests
- Inspect packaging, model label, serial traceability, connectors and accessories.
- Verify installation instructions, cable ranges, clearances and startup sequence.
- Check PV startup and MPPT operation within a safe test arrangement.
- Verify AC voltage, frequency, power quality and protection behavior as permitted by the test plan.
- For hybrid models, test battery communication, charge limits, backup transfer and low-state-of-charge behavior.
- Test monitoring, alarm history, user roles and data export.
- Record noise, thermal behavior and derating under a representative load.
- Practice the support process with a real technical question.
Use qualified personnel and suitable test equipment. Grid-interconnection and protection tests can be hazardous and may require specialized laboratories. The purpose of a sample is to reduce uncertainty, not to create a makeshift certification program.
16. Factory and quality-system review
A factory audit should follow the product flow: incoming components, storage, production, firmware loading, electrical test, burn-in where used, final inspection, labeling, packing and nonconforming-product control. Ask how calibration is managed and how a failed unit is segregated and investigated.
For repeat orders, change control matters. A component substitution, PCB revision, firmware update or connector change can affect compatibility and approvals. The purchase agreement should define which changes require buyer notification or approval.
THLinkSolar offers factory visits or audits and remote technical support. Buyers should request a visit agenda and a model-specific quality pack. Public company statements about facilities or certifications are not substitutes for documents that cover the ordered product. The most useful audit outcome is a short list of verified controls, open actions and owners—not a collection of staged photographs.
17.Commissioning records that protect both buyer and supplier
Commissioning should produce a dossier. Record site data, equipment model and serial numbers, firmware, insulation and continuity checks, protective-device settings, PV string measurements, grid measurements, battery settings, monitoring account, functional tests and photographs. Obtain sign-off from the responsible parties.
For a hybrid project, test normal PV operation, grid loss, backup operation, grid return, battery low limit, charging source, generator sequence where applicable and alarm reporting. For an on-grid system, confirm the approved grid settings and export-control operation when required. For an off-grid project, test load steps and the largest expected motor start under controlled conditions.
A commissioning file separates manufacturing issues from wiring, configuration and site issues. It also shortens remote troubleshooting because the support engineer can see the starting condition.
18. Warranty and claims: ask for the workflow, not only the years
Warranty length is only one clause. Request the exact coverage, start date, exclusions, transfer rules, remedy, freight responsibility, labor position, required evidence and expected response process. A distributor should understand whether replacement stock is advanced, repaired locally or returned.
When a claim lands on a distributor’s desk, the first email should answer the obvious questions. Which serial number? When and where was it installed? What did the grid and PV measure at the time? Add the alarm, firmware, a few clear photographs, the event log and what the installer has already tried.We agree that folder before a volume order; nobody enjoys negotiating evidence while a site is down.
Stock spares for the fleet you actually have, not for a brochure family. In one market that may mean complete swap units; elsewhere, fans, a communications board and a display make sense. First check what a trained local technician is permitted to replace. Then write the customer response promise. Reversing that order creates impossible service commitments.
19. Common procurement mistakes and how to correct them
Mistake 1: selecting from kW alone
Correction: freeze voltage, phase, frequency, topology, grid code, PV window, battery and load behavior before comparing model numbers.
Mistake 2: copying certification logos from a company page
Correction: verify the exact model, standard edition and certification scope. Keep the document in the project file.
Mistake 3: treating surge power as unlimited
Correction: match the magnitude and duration of load inrush to the documented overload curve, and test the critical load.
Mistake 4: assuming battery communication
Correction: obtain pairing confirmation for model and firmware; agree on cable pinout, protocol and settings.
Mistake 5: ignoring accessories
Correction: list every meter, CT, logger, dongle, connector and cable in the quotation comparison.
Mistake 6: using a generic “standard system”
Correction: complete a site-specific solar system design with named assumptions and a reviewed single-line diagram.
Mistake 7: ordering before the local approval path is clear
Correction: identify the utility, authority and required documents before freezing the model.
20. THLinkSolar model-family orientation
The following summary helps a buyer start a technical discussion. It is not a substitute for the latest model datasheet, manual, certificate and engineering review.
| Family | Documented role | Documented range / interface | Buyer must confirm |
|---|---|---|---|
| TP-GTI | Single-phase on-grid | 1–10 kW; 450/500 V max DC by model; 1–2 MPPT | Exact model, grid approval, current limits |
| TP-TL | Three-phase on-grid | 4–15 kW; 1000 V max DC; 160–850 V MPPT | AC arrangement, strings, market settings |
| TP-ESS / TP-EPH | Three-phase hybrid | 4–12 kW; 130–700 V battery; 2 MPPT | Approved battery, backup behavior, grid code |
| TP-HFP | Hybrid on/off-grid | 3.3–12.3 kW; 220/230/240 V; max PV Voc 500 V | Battery voltage by model, current, parallel rules |
| TP-REVO HES | Hybrid storage inverter | 6/8 kW; battery range 40–58 V | Battery protocol, transfer, accessories |
| TP-SPI | Split-phase hybrid | 8/10 kW; 48 V battery; 2 MPPT; 125–425 V MPPT | Service arrangement, load balance, approvals |
| TP-LF | Low-frequency off-grid | 1–12 kW; 12/24/48 V platforms; pure sine wave | Surge curve, transformer loads, site temperature |
| TP-HF | High-frequency hybrid/off-grid | 5–12 kW; 48 V; MPPT 80–450 V | PV current, battery communication, parallel operation |
The current THLinkSolar solar inverter catalog is the starting source for these family-level facts. Procurement should request the final datasheet revision attached to the quotation, because web pages and catalogs can be updated.
21. A complete inverter RFQ template
Copy the fields below into your inquiry. Specific answers produce a faster and more useful proposal than a long generic message.
- Buyer and project: company, role, country, city, project type, quantity and target schedule.
- How will it run? Tell us on-grid, off-grid or hybrid; whether export is blocked; and where a generator enters the diagram.
- What does the meter show? Give phase arrangement, both relevant voltages, frequency, neutral and earthing notes.
- Who approves connection? Name the utility, rule, listing or certificate, plus the date approval is needed.
- What is on the roof? Send the module model and its Voc, Vmp, Isc, Imp, temperature coefficients, string plan and design temperatures.
- What starts at night? Share daily energy, the measured peak, compressors or motors, start method and the circuits that cannot be shed.
- Which battery, exactly? Chemistry alone is not enough; add model, voltage window, capacity, current, protocol and required backup time.
- Where will the box live? Indoor/outdoor, heat, altitude, humidity, dust or salt, air movement, working space and noise all belong here.
- Who watches it? State local and remote access, interface, data owner and any fleet or API requirement.
- What must arrive as evidence? List manual, datasheet, drawing support, reports, label image and packing details.
- How is it being bought? Sample or volume, branding, port, Incoterm, payment preference and desired spare stock.
- Who supports the installer? Note language, training, commissioning help and how a claim will be opened.
A buyer who cannot complete every field should say which items are unknown.THLinkSolar can help develop a preliminary configuration, but the final design should be reviewed by a qualified local professional against the site and local rules.
22. How the inverter connects to the rest of the procurement package
An inverter decision should not be isolated from the broader bill of materials. A solar equipment supplier can coordinate modules, inverter, storage and accessories, but the buyer still needs interface control. Each item must name its electrical, mechanical and documentation boundary.
For a hybrid project, define who sizes the battery, who approves the communications pair and who owns the energy-management settings. For a rooftop project, define who owns string layout, cable routing, mounting drawings and shutdown requirements. For a distributor program, define which accessories are packed with each inverter and which must be ordered separately.
The strongest procurement pack contains a design basis, single-line diagram, model schedule, approved substitutions process, acceptance tests and RFQ comparison. That pack can be reused when the project moves from budget estimate to sample, then to volume order.
23. Frequently asked questions from B2B buyers
Which inverter type is best for a commercial solar project?
“Commercial” is only the building type. Start at the switchboard. A factory with no backup need may land on a three-phase grid-tied string unit. The same factory, after identifying a critical production circuit and storage objective, may need a hybrid arrangement.Voltage, phase, export rule, load trace, array and local approval decide between them.
Can I use a 48 V battery with any hybrid inverter?
No. “48 V class” and a high-voltage rack are different platforms. Even two products that share a nominal voltage may disagree on current, CAN messages, pinout or firmware. Ask for the pairing statement and cable detail, not a verbal “should work.”
How much PV can I connect to an inverter?
Lay the module sheet beside the inverter sheet. Check cold string Voc first, then hot operating voltage, then current and short-circuit current at each input. Only after those pass should the energy model discuss a DC/AC ratio. Local design rules may narrow it further.
Does a high maximum efficiency guarantee more annual energy?
No. Annual yield depends on the complete operating profile, array orientation, string match, temperature, clipping, downtime, wiring and many other factors. Use maximum efficiency as one verified input, not a yield guarantee.
What certifications does THLinkSolar have?
THLinkSolar web and catalog materials reference multiple standards for different products. Certification must be verified for the exact model and target market. Request the current certificate and scope with the quotation; do not assume every model carries every listed approval.
What is the MOQ and lead time?
They depend on the model, configuration, quantity, branding, accessories and current production plan. State whether you need a sample, a mixed model order or a repeat volume order, and request a dated quotation.
Can THLinkSolar provide OEM or ODM service?
The company offers OEM/ODM discussions. Branding, enclosure, firmware, packaging, documentation, certification impact, MOQ and change control should be defined in writing before approval.
Can you design the entire system?
THLinkSolar can support preliminary configuration and remote technical discussion. Provide location, service data, load profile, backup requirement, module and battery information. Final installation and code compliance remain subject to qualified local engineering and authority approval.
How should I compare inverter warranties?
Compare covered components, duration, start date, exclusions, remedy, shipping, labor, claim evidence, turnaround and local spare strategy. The number of years alone is incomplete.
What information gets the fastest useful quote?
Country/city, phase and voltage, frequency, grid code, on/off-grid/hybrid mode, PV string data, load profile, battery model, backup hours, quantity, port and schedule. A single-line diagram and load spreadsheet are especially helpful.
24. Final buyer checklist
- Topology matches the project operating mode.
- Voltage, phase, frequency, neutral and earthing assumptions are documented.
- Cold Voc, hot Vmp and current calculations fit the exact MPPT inputs.
- Continuous power, apparent power, output current and overload are separated.
- Motor starts and critical-load transfer are tested or supported by evidence.
- Battery voltage, current, protocol, cable and firmware are approved as a pair.
- Grid-code evidence covers the exact model and market.
- Temperature, altitude, enclosure and ventilation are suitable for the site.
- All meters, CTs, dongles, connectors and cables are listed.
- Monitoring ownership and remote-service access are agreed.
- Sample and volume-order acceptance criteria are written.
- Warranty, claims evidence, spare parts and change control are understood.
Buyers usually find that the right inverter becomes obvious once the interfaces are written down. The value of a good procurement process is not more paperwork for its own sake. It is fewer assumptions, a cleaner quotation, faster commissioning and a support case that can be solved from evidence.
THLinkSolar supplies inverter, PV, battery and system options for B2B projects and can review an RFQ with the engineering basis above. Send the site location, AC service, load profile, PV module data, battery requirement, grid rule, quantity and delivery destination. The team can then respond with a model-specific proposal, requested documents and a list of any remaining design questions.
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