A useful control-panel specification explains what the equipment must do, where the panel will be installed, what it connects to and how the completed system will be verified. A parts list and an enclosure size are not enough to answer those questions.
You do not need to design the panel before contacting a panel builder. You do need a clear account of the application and a way to identify missing information. This guide is for vessel builders, marine equipment suppliers and project teams preparing that brief.
Begin with the operating requirement
Describe the machine or vessel function in plain language. Explain who operates it, which actions are manual, which are automatic and how it interacts with other equipment.
A useful opening might be: “The operator needs to monitor two pieces of equipment from the wheelhouse, see which one is available and receive a clear indication when attention is required.” The designer can then investigate the necessary controls and interfaces. Simply asking for “a PLC panel” leaves the required behaviour undefined.
Include the operating conditions and any limits that the design must respect. Keep proposed preferences separate from mandatory requirements so they can be evaluated rather than copied unquestioningly into the design.
Identify the panel boundaries
Record what is supplied with the panel and what belongs to another supplier. Typical discussion points include incoming power, field devices, local controls, remote displays and links to third-party equipment.
For each boundary, nominate who supplies the information, who provides the equipment and who verifies the completed interface. A shared equipment list is more useful when each item has an owner and a current document revision. For a wider vessel upgrade, use the refit planning guide alongside this brief.
Also distinguish a control panel from a distribution switchboard or a combined assembly. Their functions and applicable design requirements may differ. Ask the designer to confirm the assembly type and compliance basis rather than relying on a familiar label.
Explain the installation environment
Give the builder the vessel location, available space, access restrictions and equipment arrangement. Describe known exposure to moisture, salt, heat, vibration or other relevant conditions without trying to select technical ratings yourself.
Include practical questions:
- Can the panel be delivered and installed through the available access?
- Where can cables enter without creating installation conflicts?
- Will doors and covers be accessible for authorised maintenance?
- Is there room for adjacent equipment and foreseeable additions?
- Are mounting arrangements coordinated with the vessel structure?
A compact panel is not automatically an easy panel to maintain. Ask the design team to balance space, heat management, access and serviceability for the actual installation. There is no single enclosure rating that suits every marine location.
Define signals and communications together
A preliminary list of sensors, instruments, commands and status indications helps establish the I/O requirement. The technical team should confirm signal types, behaviour and compatibility against the equipment documentation.
Where equipment communicates digitally, obtain the manufacturer’s interface information early. Naming a communications protocol does not, on its own, define which data is available, what each value means or which party can issue commands.
Record any dependency on another supplier’s configuration or attendance. If that dependency is absent from the programme, the panel may be ready while the overall system remains unable to operate as intended.
Agree the operator-facing behaviour
Discuss the controls and information the crew actually needs. Which conditions require attention? What should a status display communicate? How will normal operating modes be distinguished from faults or unavailable equipment?
Ask the designer to document the intended sequence and agree it with the operator before implementation. A technically complete display can still be confusing if terminology does not match the vessel’s operating procedures.
Any protective or safety-related functions require their own competent engineering assessment. Do not assume an ordinary PLC or operator screen can provide a safety function simply because it can display an alarm or send a stop command.
Establish the compliance basis and evidence
The applicable requirements should be agreed by the responsible professionals for the vessel and installation. AMSA’s NSCV electrical guidance (opens in a new tab) explains the framework for relevant commercial-vessel electrical installations and the need to consider state or territory electrical requirements.
Ask the panel supplier what design information, inspections, test records and installation documentation are included. Also establish what verification depends on the completed vessel installation rather than the workshop assembly alone. The commissioning and handover guide helps define that split.
Avoid treating the statement “marine grade” as a substitute for the required evidence. Suitability needs to be established for the component’s intended use and the assembly as a whole.
Compare quotations on the same scope
Give competing suppliers the same approved brief and document revisions. Check whether each quotation includes design, component supply, assembly, software, interface development, installation, commissioning attendance and final records. State exclusions explicitly.
Agree how design changes will be handled and which decisions must be resolved before build. Ask for proposed milestones rather than assuming a standard delivery time. Missing equipment information can affect the programme as much as component availability.
Bring the requirement not just a shopping list
WTM’s switchboard and control-panel capability connects panel building with the wider electrical and control system. Discuss the application with WTM using the operating requirement, available equipment documents and installation constraints as the starting point.