If you are an OEM product owner, a contract manufacturer or an equipment buyer preparing a first enquiry, the list below is what a competent development partner should be able to answer before the mechanical design is frozen. It is written as a set of decisions to capture, not a standard to comply with, because the right answer changes with the duty cycle, the market and the budget.
1. Define the electrical envelope before selecting a controller
Every control decision downstream inherits from four numbers: incoming supply, total connected load, the peak demand during the busiest part of the cycle, and the available footprint for the control cabinet. Write these into the requirement sheet first.
On the machines in our Cleaning Equipment Series, the supply is a stated parameter rather than an assumption. The fixed PowerDe HW02 steam cleaner is listed as a 220 V unit with a 6 kW heating element, an 80 L SUS304 tank, tap-water inlet and a combined dry/wet steam and vacuum function. The hand-pushed HMW3 is listed with a 4.5 kW PTC semiconductor heater and a 48 V working supply, and is sold in variants with and without a battery. The two designs answer the same cleaning job through completely different electrical architectures, and neither choice is correct until the site's supply, the work pattern and the operator's working radius are known.
So the first requirement entry should not read "220 V, 6 kW". It should read: what supply exists at the point of use, what the site's electrical contractor will permit, how long the machine runs between breaks, and whether a battery-fed design removes a supply problem or creates a charging and spare-battery problem instead.
2. Treat protection functions as a specification, not a feature list
Ask the supplier to list protection functions by name, and record exactly what each one does when it trips. The HW02 page, for example, names leakage, short-circuit, high-temperature, high-voltage and water-shortage protections. That list is only useful to an end user if the manual also states what the operator does next: whether the machine resets itself, whether it locks out until an engineer attends, and whether repeated resets are allowed during a shift.
This matters in a purchasing decision more than it looks. A protection that trips and stays tripped protects the element and the wiring but stops the line; a protection that auto-resets keeps the line running and quietly degrades the component. Both are legitimate designs. What is not legitimate is a datasheet that lists protections without stating the behaviour, because then the customer's maintenance team learns it by experiment.
Where the machine also carries a pressure vessel, a heating element and a pump, the control specification should say which conditions block which others in hardware as well as in software, and which of those interlocks the customer's safety reviewer will be expected to inspect.
3. Put the parameters of every subsystem in writing, including the ones nobody likes to commit to
A serious requirement sheet records, for each subsystem, the value the design guarantees and the value it does not. For the HW02 the published parameters include heating power, steam temperature, vapour pressure, tank volume, dimensions, water inlet type and working voltage. Values such as hourly water consumption, consumable life and continuous-run time are not on that page, and a buyer who needs them should ask for them in writing before order placement rather than infer them from the heater rating.
The same discipline applies on the other side of our business. On semiconductor process equipment such as the 3D Surface Vacuum Bonding Machine, the listing quotes an availability figure and a cycle time measured on a specific test piece; those numbers travel badly to a different product and a different film stack, so a purchasing specification should state the test condition the number came from and ask for the equivalent figure on the buyer's own part.
4. Decide what the machine must do when a condition is not met
Most control faults on a new product are not faults of the controller; they are missing sentences in the requirement sheet. For each process condition — temperature reached, level sufficient, pressure established, door closed — the sheet should state three things: how long the machine waits, what it shows the operator, and what it does not do while waiting. A machine that waits indefinitely looks reliable in a demo and creates a queue in a shift.
Write these sequences into one timing diagram that the mechanical, electrical and software designers all sign. That single page is what an acceptance engineer will ask for, and it is far cheaper to argue about at design review than during a commissioning visit.
5. Plan the human interface around the person who will actually use it
An operator interface on a production machine should answer four questions without a manual: is the machine ready, what mode is it in, what went wrong, and what is the first thing I should do about it. Language, icons, units and the order of modes all belong in the requirement sheet, along with who is allowed to change process parameters and who is not. A machine where every parameter is open to every user hands process stability to whoever is on shift that week.
Decide at the same time what the machine records — alarms, run time, cycle count, service events — and how that data leaves the machine. Retrofitting a data interface onto a product that was never designed to log anything is one of the most common late change orders in an equipment development programme, and it is also the change customers request most often once the first units are in the field.
6. Lock the service model at the same time as the electrical design
Serviceability is an electrical design question. Heating elements, pumps, seals, nozzles, hoses and brushes all wear; sensors drift; scale collects inside a heater where the supply water is hard, and output falls well before the machine actually fails. The requirement sheet should name the consumables, the service interval, who performs it, and whether the machine can be opened for inspection without dismantling the process section.
Where a product is intended for sale through dealers, add the training package to the same scope. A dealer can sell a machine from a datasheet; only the documentation, the fault codes and the spare-parts list determine whether that dealer can support it after the first sale.
7. Match the development route to what is genuinely new
Three situations need three different engagements. A concept that has never been built needs product development work: feasibility, a working prototype, and a design that survives a test campaign. A prototype that already works but has never been manufactured at volume needs design for manufacture, tolerance and supply-chain decisions. An existing machine that needs a new variant, a new market's electrical requirements or a different capacity band is a modification project and should be quoted as one.
Naming the situation correctly at enquiry stage stops a very expensive misunderstanding, because a partner asked to "customise a machine" may quote a modification when what is actually missing is the verification work that makes the modification safe to sell.
A checklist to take into the first design review
- Supply, connected load, peak demand and cabinet footprint agreed against the site that will install the machine.
- Protection functions listed by name, each with its stated trip behaviour and operator response.
- Guaranteed parameters separated from unpublished ones, with the test condition recorded next to every number.
- One signed timing diagram covering interlocks, wait behaviour and what the machine does not do while waiting.
- Interface language, modes, parameter permissions and the per-cycle data fields defined before software work starts.
- Consumables, service intervals, calibration access and the dealer support package inside the same scope as the electrical design.
- The development route — new build, design for manufacture, or modification — stated explicitly in the enquiry.
If you are specifying equipment rather than adapting an existing model, customized steam cleaning equipment and OEM/ODM configurations are defined against your site conditions and duty cycle instead of a catalogue page. Send the supply details, the work pattern and photographs of the surfaces concerned to Shenzhen PowerDe Automation Precision Equipment and we will review the electrical and control scope with you before anything is built.
