Separate display and controller enclosures: what to specify

Specify separate display and controller enclosures as one assembly, with a shared drawing set and an interface schedule. Each box needs its own mounting, sealing and heat plan. The connection between them needs equal attention: connector geometry, cable length, shielding and service access can determine whether the assembly works. Confirm those interfaces before approving either enclosure drawing, rather than trying to resolve them after fabrication.

Define what belongs in each box

Start with a simple assembly drawing showing both enclosures, their mounting surfaces and every interconnecting cable. Give each enclosure a unique identifier that appears on its drawings, cable schedule and parts list.

• Display enclosure: Identify the display, touch interface, local electronics, buttons and any protective window that must fit inside it.
• Controller enclosure: Identify the board, power conversion, terminals, communication interfaces and any separate mounting plate or bracket.
• Power boundary: State whether power enters one enclosure and feeds the other, or enters each enclosure separately.
• Service boundary: Decide whether either enclosure must be removable without opening the other or disturbing fixed wiring.
• Environment: Record water exposure, dust, chemicals, sunlight, ambient temperature and vibration separately for each location.
• Revision control: Put the same assembly revision on both enclosure drawings and the interconnection schedule.

Do not assume both boxes need identical construction. A sheltered controller and an exposed display can have different environmental requirements. Their shared cable still needs suitable protection along its entire route.

Use the custom enclosure specification guide for the basic enclosure requirements. The additional task here is making the boundaries between boxes explicit.

Confirm the display interface before drawing its opening

A bare LCD module and a panel-mount display require different mechanical arrangements. A panel-mount display may include a bezel, gasket and clamps. A bare module may need a carrier, protective window and a separately designed seal.

• Exact display identification: Supply the model, mechanical drawing and revision, not just the screen diagonal.
• Opening dimensions: Separate the active viewing area, bezel outline, panel opening and mounting-hole pattern on the drawing.
• Panel thickness: Confirm the acceptable thickness range for clamps, screws, gaskets and any touch interface.
• Rear envelope: Include circuit boards, connectors, mounting hardware and the space needed to insert or remove plugs.
• Window arrangement: State whether the display supplies the environmental barrier or sits behind a separate window.
• Gasket surface: Keep the required sealing land clear of holes, seams, labels and nearby hardware.
• Touch operation: Confirm that any added window is compatible with the selected touch technology and intended operation.

Check the actual display hardware against the drawing before approving the opening. Connector positions and mounting features can change between otherwise similar models.

The cutouts, cable glands and HMI windows guide covers opening and sealing fundamentals. Catalog HMI enclosures are built around specified display arrangements; a matching screen diagonal alone does not establish compatibility.

Check controller mounting and service space

Board dimensions describe only part of the required internal space. Installed height, wiring access and the removal path often control enclosure depth.

• Board geometry: Supply the outline, mounting-hole coordinates, hole diameters and component heights on both sides.
• Mounting method: Identify the proposed standoffs, carrier plate or brackets, including screw access and electrical isolation requirements.
• Underside clearance: Account for solder joints, protruding leads and components beneath the board.
• Connector clearance: Show the fully mated connector, cable exit direction and required bend radius.
• Service access: Keep programming ports, replaceable parts and mounting screws accessible in the installed assembly.
• Door or cover clearance: Check the closest approach between internal parts and the closed cover, including cover-mounted hardware.
• Heat sources: Record the dissipation of the controller, power supplies and other powered devices inside this box.

Assess heat separately for each enclosure. Moving the controller away from the display does not remove the display electronics' heat load. Likewise, a cable between boxes is not a designed thermal path.

The PCB enclosure fit article explains why the case and board layout must be coordinated. For a split assembly, apply that fit check independently to both boxes.

Write one interconnection schedule

List every cable crossing between the display and controller enclosures. Specify both ends together so connector selection does not create incompatible openings or an impossible assembly sequence.

• Length limits: Confirm the permitted cable length for the actual electrical interface and cable construction.
• Connector passage: Decide whether a preterminated connector must pass through an opening before the entry is sealed.
• Assembly sequence: Confirm whether glands or seals must be fitted before cable termination.
• Strain relief: Prevent cable weight and service movement from loading board connectors or sealing interfaces.
• Shielding and bonding: Define the required termination method without assuming that mechanical contact provides an adequate electrical connection.
• Separation: Plan routing to limit interference from power wiring and switching devices, following the connected equipment's instructions.

For example, a measured route of 36 in [914 mm] plus two 6 in [152 mm] service allowances totals 48 in [1219 mm]. That is a routing estimate, not permission to exceed the interface's supported length. Check connector measurement references before ordering a cable assembly.

The bulkhead connector and cable gland comparison helps define the disconnect boundary. Use the sealed-entry strain relief article when cable movement could load the seal.

Review sealing and installed clearances together

Review the enclosure as installed, not just as an empty shell. A suitable body does not establish the rating of an assembly containing unreviewed openings and components.

Our custom enclosure ratings are manufacturer ratings for the specified design; the enclosures are not UL listed. Where NEMA 4X is required, identify that requirement for each completed enclosure and review all interfaces against it.

• Material: Specify the grade for each box. Consider 304 stainless for general service and 316L where chloride exposure warrants it.
• Entries: Match each gland or connector to its cable, panel thickness, mounting orientation and environmental requirements.
• Unused openings: Identify compatible closure components rather than leaving future openings unresolved.
• Mounting: Show brackets, fasteners, mounting surfaces and any penetrations through the enclosure boundary.
• Cover movement: Draw the opening or removal envelope, including clearance from the neighboring enclosure and connecting cables.
• External connectors: Leave enough space to grip locking collars and withdraw plugs without forcing a sharp cable bend.
• Water exposure: Avoid arrangements that collect water around entries or direct runoff toward sealing surfaces.
• Electrical protection: Define protective bonding and circuit protection where required by the installed equipment and applicable rules.

Use the custom stainless enclosure and cutout options to distinguish modifying a catalog body from specifying a new body. Neither approach removes the need to review the completed sealing arrangement.

Define branding without conflicting with seals

Branding belongs on the mechanical drawing because its location can compete with mounting hardware, gasket lands and required equipment markings. Do not leave its placement to an unspecified finishing step.

• Artwork: Supply vector artwork where available, with text, proportions and required colors identified.
• Location: Dimension the marking from fixed enclosure datums, not from the display's visible image.
• Process: State whether you want printing, engraving, a label recess or a separate nameplate, then confirm available processes.
• Attachment: Identify any proposed holes, studs or adhesive surfaces for separate plates.
• Exposure: Record cleaning chemicals, abrasion, sunlight and temperature that could affect marking durability.
• Required information: Reserve space for assembly identification, electrical markings and warnings required for the completed equipment.

Do not assume a decorative label can cross a gasket surface or cover a fastener needed for maintenance. Keep branding requirements separate from mandatory identification so later artwork changes do not disrupt the mechanical design.

Send one coordinated quote package

Send the complete assembly package with both enclosure requests. Separate files are useful, but they need shared identifiers and a clear record of the interfaces between them.

• Assembly drawing: Both boxes, installation orientation, mounting surfaces, cable routes and service envelopes.
• Enclosure drawings: Width, height, depth, material, required rating, mounting details and dimensioned openings for each box.
• Hardware drawings: Display, board, connectors, glands, brackets and other items that control fit or sealing.
• Interface schedule: Cable functions, diameters, connector details, lengths, shielding and disconnect arrangements.
• Environmental information: Temperature range, estimated internal heat, water exposure, chemicals and vibration at each location.
• Branding package: Artwork, locations, proposed marking process and required identification areas.
• Assembly requirements: Quantity, supplied components, responsibility for cable termination and checks required before acceptance.
• Approval record: One revision list showing that both enclosure drawings and the interface schedule agree.

We build custom enclosures from one piece, with customer-defined material, dimensions and cutouts. Confirm any additional mounting or marking work explicitly in the quote and approval drawing.

Before approval, trace every connection from its board or display socket to its destination. Check the connector envelope, entry seal, cable support and removal path at each end. That final interface review catches mismatches that separate enclosure drawings can miss.

Enclosures for this job

Catalog sizes that suit the job this article answers, picked from its subject; open one for its full specifications.

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