A roof-entry housing is a small line item with two different failure paths: water can pass the roof interface, and water can pass along a cable through the entry seal. A useful RV solar cable-entry RFQ identifies both paths, the actual cable diameters and the complete roof assembly. A vendor's “IP68 cable gland” label alone cannot approve a hole cut in an RV roof.
This is a buyer's evidence checklist, not a drilling or electrical installation instruction. Have the vehicle builder or qualified installer approve the roof location, structural and weatherproofing detail, electrical routing and applicable market requirements. The solar roof-mount flashing guide deals with a separate mounting-penetration detail; this guide concentrates on the cable passage.
Define the cable before selecting a seal
List each cable's manufacturer and part number, construction, measured outside-diameter range including tolerance, connector or termination, minimum bend requirements and UV/exposure classification. Record how many cables pass through each opening. A conductor's cross-sectional area is not its outside diameter; neither a nominal “4 mm² PV wire” nor a connector family proves fit in a particular bung.
As a model-specific example, Scanstrut lists its DS-HD6-BLK double entry for two cables of 5–6 mm outside diameter and supplies two 5 mm, two 6 mm and two blank bungs. Its product record, Issue 2 installation instructions and technical drawing show how a buyer can cross-check a named part, its supplied seals and its cable envelope. These dimensions apply to that part only; they do not define an interchangeable gland size.
Worked screening example, not a product approval: suppose the chosen cable drawing states 5.8 ±0.3 mm outside diameter. Its allowed envelope is 5.5–6.1 mm. A seal published for 5–6 mm does not cover the 6.1 mm worst case on its stated range. Hold the match for an approved cable/seal alternative or written manufacturer clarification. A nominal 5.8 mm value hides that mismatch. Even an in-range diameter still requires the correct bung, assembly method and installed seal check.
Review the roof and cable seal as separate interfaces
Ask for a section drawing through the roof showing roof material and thickness, substrate or reinforcement, opening, fasteners, entry base, gasket or sealant, and interior finish. Identify where bulk water travels across the roof, where it is diverted past the entry, and which interface closes the roof cut. Then identify the separate compression path around each cable and how unused ports are sealed.
Scanstrut's DS-HD6-BLK instructions identify a 25 mm deck opening, base, gasket, shell, bungs and supplied fixings for that named assembly. They tell the installer to choose the bung nearest the cable diameter and include different fixing guidance for soft, hard and metal substrates. They are not a universal drilling template or approval for any composite RV roof. Require the current document revision and a vehicle-specific installation detail before a roof is cut. Scanstrut DS-HD6-BLK instructions.
An ingress rating belongs to a tested component and configuration. The DS-HD6-BLK page claims IP68 for its cable seal; that claim does not establish the leak performance of a newly cut roof, altered gasket, substitute cable or poorly prepared substrate. Ask what exact assembly was rated and what the roof builder will inspect. For the distinction between IP code and installed assembly, see the IP67 versus IP68 procurement guide.
Compare two entry architectures without treating them as interchangeable
Two original-manufacturer documents illustrate why a buyer needs an assembly drawing rather than a generic keyword search. The Scanstrut DS-HD6-BLK uses a base, gasket, shell and selected cable bungs, with mechanical fixings described in its instructions. Its published cable envelope is two 5–6 mm cables. The old Renogy MTS-CE cable-entry housing manual describes a bonded membrane with two cable glands and a published 6–12 mm gland range. Its installation pages call for a roof wire opening, surface preparation, adhesive applied to the membrane and gland tightening after routing. These are different products and installation concepts, with different documents and limits. Scanstrut DS-HD6-BLK instructions; Renogy MTS-CE manual, version 1.02.
The Renogy manual uses “drill-free mounting” in its feature list but also instructs the installer to drill an opening for the cable. The reasonable reading is that the housing attachment is bonded rather than screwed; it does not mean that a cable enters a closed roof without a penetration. Its part name, manual revision and 2017 revision date must be checked against the exact product currently offered. Do not apply the 6–12 mm MTS-CE range to Renogy's newer or differently numbered entry products. The named comparison gives the buyer questions to ask, not a recommendation to substitute one supplier for another.
For an RFQ, define whether the project allows mechanical fasteners into the roof, an approved adhesive bond, or a specific vehicle-builder detail. If a bond is proposed, request the adhesive identity, roof substrate and finish, cleaning/abrasion procedure, primer if required, bead or coverage pattern, application temperature, cure conditions, inspection cue and rework method from the relevant product manufacturers. A statement that an adhesive is “marine grade” does not prove compatibility with the roof coating or the plastic housing. If fasteners are proposed, request the full stack, pilot/opening plan and seal around each penetration. Neither method should be approved from the entry housing brochure alone.
Keep water shedding distinct from adhesive strength. A strong bond may leave a discontinuity in the seal path; a locally watertight bead may have inadequate durability under travel vibration or roof flex. Ask the vehicle builder how roof movement, cleaning, sunlight, standing water and seasonal temperature affect the chosen location. These are project inputs and inspection questions, not claims that a particular product has been qualified on every roof material. In a multi-layer roof, also ask how the hole edge is protected and whether moisture could migrate within the roof stack without becoming visible inside the vehicle.
Select the entry by a worst-case envelope
Prepare a one-page selection worksheet before soliciting prices. Row one is the roof: outer skin, coating, core or insulation, inner liner, thickness tolerance, slope, allowable hole locations and structural no-go areas. Row two is each cable: exact part, minimum and maximum jacket OD, minimum bend conditions, connector envelope and expected replacement method. Row three is the entry: model, port count, seal options, cable-size range, mounting method and installation-revision number. Row four is the surrounding installation: panel edge, walking or cleaning access, other roof equipment, interior obstruction and service clearance. Without those rows, bids may look comparable while answering different designs.
Use the entire OD range. If the drawing gives 6.0 mm nominal with a ±0.2 mm tolerance, the possible cable measures 5.8–6.2 mm. It should not pass a published 5–6 mm screen merely because the nominal is 6.0 mm. Conversely, a seal's published range alone does not prove the cable jacket's shape, surface texture or compression behavior suits it; confirm the manufacturer's instructions for that cable construction and use a production-representative sample. No compression allowance, bend limit or pull-force number should be invented to close the gap.
Do the same envelope check for connectors. List each connector body's maximum width and length, any locking feature, and the assembly step at which it is attached. A roof hole intended only for a cable jacket may not pass the connector body. One design might route unterminated cable and make a controlled connection afterward; another might use an entry system expressly intended for preterminated cables. The choice affects assembly skill, electrical inspection, serviceability and the roof opening. Do not modify a listed connector, gland or seal to force a cable through. Obtain the selected manufacturers' approved process and record which interface owns the sealing claim after assembly.
Unused ports deserve a separate line in the drawing. A dual entry purchased for one string today may have a future expansion port, but “future” is not a closure method. Name the manufacturer's blank, plug or approved gland configuration and show it in the first article. If the second cable is later installed, revisit port size, routing, seal assembly and inspection; the first approval did not evaluate the new cable. If two cables share one oversized port, require explicit manufacturer approval rather than assuming that a larger gland will compress symmetrically around both jackets.
Make roof position a recorded design input
Mark the proposed position on a roof plan with dimensions to panel frames, rails, vents, roof edges and interior equipment. Indicate vehicle travel direction and any orientation instruction on the entry housing. The position must provide a practical route that avoids a tight immediate bend while leaving the base accessible for inspection. A spot hidden beneath a permanently bonded panel may be attractive in a rendering but difficult to examine or service after a leak is reported.
Ask who owns approval of the roof cut. The PV supplier can document its cable and entry hardware, while the vehicle builder or designated installer must assess the roof structure, hidden wiring, substrate condition and manufacturer's warranty process. Record the decision in a drawing rather than a verbal note. Roof photos should show the proposed location before any cut and after the entry is installed, with enough landmarks to identify the location later. A close-up of sealant without location context does not show whether the housing was placed in the reviewed drainage path.
Consider an RV with a curved outer skin or a roof coating that has been repaired. The chosen product's nominal flat base may need a manufacturer-approved detail for that curvature and coating. Do not simply add more adhesive to bridge an unknown gap. Ask for the flatness or curvature tolerance, substrate preparation and whether a mounting pad is allowed. If the answer is absent, the installation is a hold point regardless of the cable seal's IP claim. This protects both procurement and the service team from inheriting an unreviewed roof modification.
Plan cable routing and future service
Draw the route from module leads to entry, through the roof and onward to the electrical equipment. Mark connector positions, support points, movement or vibration exposure, edge protection, abrasion risk and the service access needed to replace a cable or seal. Do not assume a preterminated connector will pass through a cable-sized bung or a roof opening. If a termination must be made after routing, specify the connector manufacturer's approved process and who will inspect it; the PV connector compatibility guide covers that separate mating and crimp decision.
The roof penetration should not be used as the cable's only strain relief unless the selected product instructions and installation design explicitly allow it. Keep bends, free length and movement control in the cable drawing, and use the cable assembly strain-relief guide to frame the separate mechanical review. Preserve access to inspect or replace the entry without removing unrelated roof equipment, when the vehicle design permits it.
Specify the harness handoff on both sides of the roof
The exterior drawing should show the transition from module pigtail to supported roof cable, the location of any mating connector and the distance to the entry. The interior drawing should show where the cable emerges, how it is protected from cut edges, where it is supported and where it reaches the next approved electrical component. Those drawings make it possible to ask whether roof movement loads the seal, whether a technician can disconnect the array for service, and whether a cable can be replaced without opening a larger area of the vehicle interior.
For each side, request an assembly photograph on the first article with identification tags that match the drawing. The exterior photograph should expose both entry ports and the complete base perimeter, not just the top shell. The interior photograph should show the roof opening treatment and first support point where safely accessible. The photographs are trace records, not substitutes for an inspection of hidden interfaces. If the roof liner makes the penetration inaccessible after assembly, the quality plan should define the check before the liner closes and tie it to the vehicle serial or production record.
Electrical design remains separate. The cable-entry housing does not choose PV string voltage, protection, isolation or conductor ampacity. Identify the applicable cable and connector evidence in the BOM, and have the electrical designer establish routing, protective devices and isolation. A quote for a “solar roof gland kit” without cable details should not be interpreted as an approved complete PV wiring system. The buyer can ask the vendor to list exactly what is supplied and what the vehicle maker must provide.
Compare three hypothetical supplier replies
This is a fictional document-review exercise. It is not a test result, customer installation or endorsement of any named product. The buyer provides an RV roof stack, two PV cable drawings with 5.7–5.9 mm OD, a sketch of the roof route and an interior service hatch location.
Reply A prices a “universal waterproof solar gland,” attaching a photograph and an IP68 icon. It gives no gland part number, gasket drawing, cable OD range or roof installation instructions. The low price cannot be normalized against the other bids, because the quotation does not define what was tested or how the roof interface is made. Hold A and request a controlled BOM and documents.
Reply B names a two-port entry with a published 5–6 mm cable range, the correct bungs and an installation drawing. The 5.7–5.9 mm cable envelope passes the initial OD screen. B also shows the roof hole, fastener and gasket method but omits the intended substrate and interior cable support. It is suitable for a design-review sample, not automatic production release. Ask the vehicle builder to review the roof stack and the supplier to add the harness handoff.
Reply C names a bonded housing with a broad gland range and cites a manual for an older product number. The cable diameter looks plausible, but the supplier has not shown that the manual belongs to the offered revision, that the adhesive works on the specified coating, or how the roof hole edge is treated. Hold C for part identity, current instructions and roof-substrate compatibility. A broad cable range cannot overcome missing bond evidence. The example shows how evidence quality and design fit, rather than a single advertised ingress code, determine the next purchasing step.
If the actual cable drawing later changes to 5.8 ±0.3 mm, its upper limit reaches 6.1 mm and the initial B screen fails. The buyer should issue a revision notice and repeat the seal selection, rather than silently accepting the earlier sample approval. This is a calculation on hypothetical drawing values, not a claim about the physical cable or product.
Give every bidder the same acceptance schedule
On small screens, swipe or scroll sideways to read every column. Keyboard users can focus the table and use the arrow keys.
| RFQ field | Buyer input | Supplier evidence and release hold |
|---|---|---|
| Cable and ports | Cable part numbers, minimum and maximum OD, number of conductors, connector locations | Exact entry and bung part numbers, published OD envelope, unused-port closure; hold if any OD tolerance falls outside the named seal range |
| Roof interface | Roof stack, thickness, slope/orientation, opening location and substrate | Current installation drawing, fasteners, gasket/sealant specification and water path; hold if the detail is generic or for a different substrate |
| Route and service | Roof-to-equipment path, support, bend and replacement access | Section/route drawing, edge and abrasion protection, cable or seal replacement sequence; hold if a connector cannot pass or no controlled termination process is supplied |
| Acceptance and change | Target market and project inspection plan | Model-specific ingress evidence, first-article photos of both interfaces, revision/lot trace and change notice; hold if an IP claim is substituted for the roof inspection |
At first article, compare the installed cable markings and measured OD with the approved drawing, then photograph the correct seals, closed blank ports, seated base and cable exit from useful angles. Record the roof builder's inspection or water-check method and acceptance criteria before testing. A photograph cannot prove a hidden gasket has sealed; a product-level ingress claim cannot replace the project roof check. Later changes to cable jacket, seal, roof material or adhesive require a fresh affected-interface review.
Separate incoming inspection from installation acceptance
Incoming inspection can confirm what arrived: entry-body and bung part numbers, gasket presence, fastener kit, packaging condition, markings and document revision. It cannot by itself establish that the roof is sealed. The installation acceptance record starts when the approved roof substrate and cable are assembled. It should link the incoming lot to the vehicle build, identify the installer and approved method, and record the checks made while each interface is still visible. This separation prevents a purchasing team from treating a passed component inspection as a passed vehicle installation.
For a first article, ask the responsible installer to record the measured cable OD, selected bung or gland, roof opening location, preparation method, complete base perimeter, fastener or bond condition, unused-port closure and cable support. The inspection plan should say which observations are required before the housing closes and which can be checked afterward. If the builder uses a water check, it must define the project-specific method, duration, observation locations and disposition of any leak; this article supplies no universal spray or immersion protocol. Retain the result with the drawing revision so future builds can be compared on the same basis.
Change control is more than a supplier notification box. A new PV cable jacket may change outside diameter and surface behavior; a new roof coating may change adhesive compatibility; a new entry housing revision may change bung or gasket geometry. Each change should trigger a short impact review naming the affected drawing, seal, substrate, installation process and inspection record. A supplier may offer an apparently equivalent part to improve availability, but the buyer needs the substitute's own installation and evidence package before approving it. The replacement price or delivery advantage should be considered only after its technical scope is clear.
Send a roof-entry RFQ that can be quoted
Send the roof cross-section, cable drawings with OD tolerances, number of entries, route sketch, connector strategy, market and inspection requirements. Request a controlled BOM, manufacturer installation documents, section drawing, sample configuration, seal/roof-interface evidence and the bidder's own price, MOQ and lead time. Do not assume any specific SINAWATTS material, certification, stock or installation capability from this guide. Identify Cable Glands or Solar Accessories in the inquiry message and describe the vehicle roof and cable-entry need.
Send an RV solar cable-entry RFQ
Buyer FAQ
Can I order a seal from the cable's conductor size alone?
No. Ask for the exact cable jacket's minimum and maximum outside diameter, then compare that entire range with the selected seal and bung instructions. Cross-sectional area does not define jacket OD.
Does an IP68-marked entry make an RV roof waterproof?
No. The component's published IP claim has its own tested scope. The roof opening, substrate, base gasket or sealant, orientation and workmanship need a separate vehicle-specific review and acceptance check.
Can a factory-terminated PV connector be fed through the cable seal?
Only if the selected entry's instructions and geometry permit that exact connector and the seal remains valid afterward. Do not cut off a connector or enlarge a bung without an approved termination and sealing plan.
What is the first sample worth checking before a volume quote?
Ask for a representative cable-and-entry assembly on the intended roof stack. Verify cable OD, port closure, base seating, cable support, connector sequence and revision-controlled inspection evidence before approving a substitution or production release.