Pre-shipment inspection and field acceptance
Two different tests that get talked about as if they were one. Inspection happens in China and answers “is this the right equipment, complete and undamaged?” Acceptance happens on site and answers “does it deliver the duty it was sized for?”
Passing the first tells you nothing about the second. You want both, and they need different people in different places.
Before shipment
Identity, completeness, condition, documents, packing. Everything that is cheap to fix while the goods are still here.
After installation
Measured flow at measured head, against the design duty point. The only test that proves the system works.
Photograph everything
Nameplates, serial plates, cabinet interior, crate contents. Costs nothing and settles most later disputes.
Before the container closes
Everything on this list is cheap to correct while the goods are still in China and expensive or impossible to correct afterwards. That is the whole logic of the stage.
| Quantity and model against the packing list | Count it, and check model numbers against the bill of materials rather than against the description. Substitution of an equivalent model is the single most common finding. |
| Serial numbers recorded | Against the register, if one was agreed. This happens at packing or it does not happen. |
| Nameplate against the offer | Motor power, voltage, phase, frequency. A photograph of every nameplate type costs nothing and settles arguments later. |
| Visual condition and finish | Cable gland integrity, paint, impeller free to turn by hand, no transit damage already present. |
| Cabinet build against the drawing | Breakers, isolator and surge device present and to the ratings on the drawing. This is where a merged protection list gets found out. |
| Documents physically present | Manuals, certificates, test reports, packing lists. Paperwork that is promised to follow by email usually does not. |
| Packing method as specified | Crate type, weight per package, modules oriented correctly, desiccant in with the electronics. |
The finding that comes up most
Model substitution. An equivalent item, often genuinely equivalent, swapped in because the original was out of stock and nobody raised it. Checking model numbers against the bill of materials rather than against the written description is what catches it, and it is why part numbers on every BOQ line matter.
After it is installed
The site test is the one that decides whether the system does what it was bought to do. It needs to happen at full irradiance, with numbers written down rather than observed.
| Measured flow at the discharge | A bucket and a stopwatch is acceptable on a small kit; a flow meter on anything larger. Recorded, not estimated. |
| Effective total dynamic head | Measured on the day, which will differ from the design figure because the water level is what it is. Both numbers should appear on the sheet. |
| Against the design duty point | The comparison is the whole point. Measured flow at measured head, next to the point the system was sized for. |
| Protections exercised, not assumed | Cover the array or block the discharge and confirm the drive actually stops. A protection that has never been triggered is an untested claim. |
| Earthing continuity | Pump body to cabinet earth bar, measured. On a borehole this is the one nobody checks and the one that matters. |
| Signed by both sides | A test sheet with numbers and two signatures is what closes the handover. Without it, the argument stays open indefinitely. |
Formal procurements often require this as a signed test sheet with measured flow and effective head recorded, carried out by the supplier or their local partner in the presence of the buyer. Where that is a contract requirement, it belongs in the scope and the price from the start, because somebody has to travel to site with instruments.
When the site test comes in low
A measured flow below the design figure is common and usually has a findable cause. Working through these in order settles most of them before anyone blames the pump.
| Head on the day is higher than design | Drawdown deeper than the pumping test suggested, or a dry season. Measure it rather than assuming the design figure still holds. |
| Pipe is narrower than specified | A nominal size bought in a heavier pressure class has a smaller bore, and friction climbs fast. Check what was actually installed. |
| Irradiance at test time | A test at 700 W/m² is not a test at full output. Note the conditions on the sheet or the number means little. |
| Air in the line, or a partly closed valve | Simple, and worth eliminating before anything else. |
| Array smaller than designed, or shaded | Count the modules and look at what the array sees at 9am and 4pm, not at noon. |
| The pump genuinely underperforms | Possible, and this is where the signed curve from the order stops it being a matter of opinion. |
What we do, and what we do not
We check goods against the bill of materials at the audited partner factory before shipment, photograph nameplates and cabinet interiors, and make the goods available for your own inspector or a third-party agency if you appoint one. We think you should appoint one on a container-scale order, and we would rather you did.
Site commissioning and acceptance testing are not in our scope. We do not have crews in these markets, so the installation and the test are done by your own contractor. What we can do is provide the design duty point, the pump curve and the test sheet format so the comparison is unambiguous when your contractor runs it.
Planning an inspection?
Tell us the scale and where the goods are going. We will set out what we check ourselves and what an independent inspector should be asked to look at.
Inspection and acceptance FAQ
What is checked in a pre-shipment inspection of solar pump kits?
Quantity and model against the bill of materials, serial numbers against the register, nameplate data against the offer, visual condition, the cabinet build against its drawing including breakers and surge protection, that the documents are physically in the crates, and that the packing matches what was specified.
What is the difference between pre-shipment inspection and site acceptance?
Pre-shipment inspection happens in China while the goods are still in the supplier’s hands and is about identity, completeness and condition. Site acceptance happens after installation and is about performance: measured flow at measured head, compared with the duty point the system was sized for. They test different things and you want both.
How is a solar pump commissioning test done?
Run the pump at full irradiance, measure the flow at the discharge and the effective total dynamic head on the day, and record both next to the design duty point. Then exercise the protections deliberately: cover the array, block the discharge, and confirm the drive stops rather than assuming it would.
Why measure head on site when it was calculated at design stage?
Because the water level on the day of the test is what it is, not what the driller reported. Measured flow means nothing without the head it was measured at, and a test sheet showing flow alone is not evidence of anything.
Who pays for pre-shipment inspection?
Normally the buyer, whether they send their own inspector or appoint a third-party agency. Either is worth it on a container-scale order. The supplier should be arranging access and having the goods ready, not deciding whether the inspection happens.
What should a site acceptance test sheet contain?
Date and conditions, the measured flow, the measured total dynamic head, the design duty point for comparison, confirmation that each protection was triggered and behaved correctly, earthing continuity, and signatures from both sides. Numbers and two signatures is what closes a handover.
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