English
Most guides about buying from a Chinese factory stop at how to choose the supplier. This one starts where those guides end: the purchase order has been agreed, and the next six weeks decide whether the shipment arrives as specified or arrives with a problem nobody can fix from the other side of the world.
Below is the order-to-delivery sequence for AC contactors, covering what actually sets the AC contactor MOQ, how lead time splits between production and paperwork, what to lock down on the order confirmation, what to inspect before the container is sealed, and how to handle packaging and documents so the goods clear customs without a second delay.
MOQ is not a policy a salesperson invents. For contactors it comes out of three production realities, and knowing which one is driving your number tells you whether it can be negotiated.
| Driver | Why it sets a floor | Can it move? |
|---|---|---|
| Production batch per frame | Assembly is organised by frame, not by order. A small run still occupies the line for a setup cycle. | Partly — a factory may merge your quantity into an existing batch of the same frame |
| Coil voltage and type | A standard 24 V DC coil is wound in volume; a 110 V 60 Hz coil is a separate small run | By choosing a stock voltage, usually without extra cost |
| Private label and packaging | Nameplate printing, marking and inner-box artwork each carry a setup | Only by accepting a higher quantity, since the setup is amortised across units |
If the frame size is not yet settled, the SMO-K selection guide works through current, duty and coil options before any quantity is discussed.
The practical consequence: if your quantity is below one batch and you do not need private label, ask whether the frame can be supplied from stock or merged into a scheduled run. That is a different question from “can you lower the MOQ”, and it usually gets a more useful answer.
Quoted lead time is usually a single number, which hides the fact that it is made of three parts with very different behaviour.
When a supplier quotes “25 days”, ask which parts are included. A 25-day quote that excludes document preparation is not the same as a 25-day quote that includes it, and the difference shows up as a container sitting at the port while a certificate of origin is being issued.
These two numbers interact, and reading them separately leads to the wrong order size. A larger quantity spreads the private-label setup across more units and lowers the unit cost, but it also lengthens the production block and ties up capital in stock you may not need for a year.
For a first order from a new supplier, the useful compromise is usually the smallest quantity that clears the private-label setup and still fits one production batch — not the largest quantity the discount table rewards. The second order is the time to consolidate frames and take the volume break, once you know the product behaves as specified in your own panels.
Most post-shipment disputes trace back to an order confirmation that was too thin. Eight lines should appear in writing before production starts, because each one is expensive to correct afterwards.
| Line | What to state explicitly |
|---|---|
| Model and frame | Exact frame designation plus AC-3 rated current and rated operational voltage |
| Coil | Voltage, AC or DC, and whether it is a stock or production item |
| Poles and auxiliary contacts | 3P or 4P, and the exact NO/NC configuration as supplied |
| Quantity and batch split | Total quantity plus how it divides across frames |
| Private label scope | Nameplate content, marking position, inner box artwork, master carton marking |
| Packaging | Inner box quantity, moisture protection, pallet type, total carton count |
| Incoterm and port | FOB or CIF, named port, and who books the freight |
| Documents | Which documents are included and which are quoted separately |
Two of these deserve emphasis. The auxiliary contact configuration is the single most common mismatch, because a bare frame plus a separately packed add-on block is not the same shipped item as a factory-fitted block, even though the function is identical. And the private-label scope needs to be specific about position, not just content; the ODM and OEM process sets out which parts carry a one-time setup and which recur per unit — a nameplate printed in the right wording but placed on the wrong face is a rework, not a fix.
Inspection is not a formality, and it is not the same as trusting the routine test record. A workable pre-shipment check has four parts.
If you cannot attend, a third-party inspection is worth the fee on a first order and usually unnecessary afterwards. What matters is that the inspection happens before the container is sealed, because afterwards every correction becomes a claim rather than a fix.
Packaging is where the cheapest savings are made and where the buyer pays for them. Four points are worth specifying rather than accepting the default.
The document set for contactors is short, but each item has a failure mode. The commercial invoice must match the packing list exactly in quantity and description; a discrepancy is the most common cause of a customs hold. The certificate of origin is issued per destination and takes time, so it should be requested at order confirmation rather than at shipment. The HS code should be agreed in writing before the order, because a classification dispute at destination is resolved after the goods arrive, not before.
If your customer’s audit requires a specific document package beyond these, say so before the production order is placed. Preparing documents after the goods are packed is possible, but it turns a routine shipment into a rushed one. What ships with each order, and what has to be arranged separately, is set out on the AC contactor supplier page.
Note that this section is about shipment problems, not product faults. If a contactor fails in service after installation, that is a different diagnosis — the AC contactor troubleshooting guide covers the seven faults that account for most field failures.
Shortages and damage are handled very differently depending on when they are discovered, which is why the inspection step above matters more than any clause in the contract.
It depends on the frame and the level of customisation rather than on a fixed industry number. A standard frame with a stock coil has the lowest floor; private label and non-standard coil voltages raise it, because both carry a setup that has to be spread across the run. Ask which of the three drivers is setting your number — that determines whether it can be reduced.
Longer than the equivalent standard order, because the nameplate and packaging are produced separately from the contactor itself. The extra time is in the print and setup stages, not in the assembly. Confirm the lead time breakdown in writing, with the paperwork stage listed separately.
On a first order, either is worth it. The value is not in the inspection itself but in it happening before the container is sealed, while a correction is still a correction. From the second order onward, most buyers rely on loading photos plus a periodic third-party check.
If your destination or your customer requires one, it should be requested at order confirmation, because it is issued by an authority rather than generated by the factory. Requesting it after packing is what turns a routine shipment into a delayed one.
An order confirmation that left the auxiliary contact configuration or the private-label position unspecified. Both are visible in a photograph and both are expensive to correct after the container has sailed, which is why they belong in writing before production begins.
None of this is complicated, but all of it happens before the goods move, and almost none of it can be fixed afterwards. If you are still choosing between suppliers rather than executing an order, the supplier sourcing checklist covers that earlier stage using the same framework, and the price comparison guide covers how to read the quotation you are about to convert into an order.
