Every control panel needs its cables to arrive somewhere, and the two proven ways to get many of them through one wall are a drilled gland plate and a split cable entry frame. The gland plate is a sheet or plate drilled with round holes, each carrying a cable gland or sealing grommet for a bare cable end. The split frame is a rectangular housing with two-half elastomer grommets that close around cables which already have connectors molded on. Pick by what is on the end of the cable: bare ends and high packing density point to the gland plate; pre-terminated cables and retrofit work point to the split frame. Most large panels end up with both on the bottom face.
Our enclosures are rated NEMA 4X / IP66 by the manufacturer; not UL listed. The entry hardware you mount carries its own manufacturer rating, and the finished penetration is only as good as the worst-sealed component.
Side-by-side comparison
| Property | Drilled gland plate | Split cable entry frame |
|---|---|---|
| Cable ends | Bare, terminated inside the panel | Pre-terminated with connectors, or full harnesses |
| Sealing method | Individual cable glands or self-sealing grommets | Split elastomer grommets clamped in a frame |
| Typical manufacturer rating | Up to IP68 per IEC 60529 for well-matched glands | Up to IP65/IP66 per IEC 60529 for frame and grommets |
| Packing density | High; holes spaced on a grid, many per plate | Moderate; each grommet block holds several cables |
| Strain relief | Built into each gland, adjustable per cable | Integrated in the grommet blocks, less adjustable |
| Retrofit on existing cables | No; cables must pass through the holes | Yes; frame and grommets split around installed cables |
| Cutout | Round holes, one per gland | One rectangular cutout per frame |
| Corrugated conduit and hoses | Yes, with matching glands | Yes, with the correct grommet block |
| Cost of adding one cable later | Drill a new hole in a removable plate | Push into a spare grommet slot if one exists |
Where the gland plate wins
The gland plate is the denser and tighter option. A 12 x 8 in plate drilled on a 2 in grid takes a dozen or more glands, and each gland seals one cable at its own rating. If every cable arrives on a reel with bare ends and you land terminals or ferrules inside the panel, there is no reason to give up that density.
Sealing head is higher too. A properly matched gland with a clamping range that fits the cable jacket is commonly rated IP68 by its manufacturer, where most split frames stop at IP66. On a panel that sits in a washdown zone or gets hosed from a nozzle close by, glands hold the last margin.
Strain relief is per-cable and adjustable. A gland grips the jacket directly, and you set the compression yourself. That matters for heavy power cables and for any cable pulled tight by its route. The clamping-range guide explains how to match a gland to a cable so the seal actually grips.
Cost of change is low when the plate is removable. Drill one more hole in the shop, swap the plate, and the enclosure body is untouched. That is the whole argument for specifying a gland plate on a stainless enclosure instead of drilling the enclosure wall itself.
Where the split cable entry frame wins
The frame wins the moment a connector is on the cable. A Cat6 or M12 cable with a molded connector cannot pass through a gland hole smaller than the connector, and a hole that big cannot seal. The split frame sidesteps it: open the grommet, lay the cable in with its connector inside the panel, close the halves, and clamp the frame. No connector is cut off, so no factory termination is redone and no cable warranty argument starts. Getting a single connector through a gland is possible with oversize or removable glands, but for a bundle of them the frame is faster.
Retrofit is the second win. Because the frame and every grommet split, you install them around cables that are already pulled and terminated. On a machine rebuild where the panel cannot be de-terminated, that is the only practical option short of cutting and re-pinning every cable.
Changeover is faster on the floor. Spare slots in a grommet block take a new cable in minutes with no drilling, as long as you left a slot. For panels whose cable count grows every year, budget two or three empty positions per frame at commissioning.
The frame also handles mixed media cleanly. Round cable, corrugated conduit and pneumatic hose fit the same frame with different grommet blocks, which keeps one rectangular cutout instead of three hole types.
Choosing by environment and panel type
Outdoor panels with rain and sun: gland plate for the seal margin, bottom entry, drip loops, and UV-rated grommets where the frame must be used. The outdoor cable gland orientation rules apply to frames too; never point either one straight up.
Washdown and food areas: either system at IP66 with 316L stainless hardware where chemicals reach it. Frames are available in plastic and anodized aluminum; pick the frame material the same way you pick 316L wall-mount enclosures for the environment, not for price.
Indoor dry control panels: split frames everywhere, because install speed and retrofit flexibility outweigh the last point of IP rating.
Pre-terminated harness delivery: frame, full stop. If the harness arrives assembled with connectors both ends, the frame is not a choice, it is the requirement.
Corrugated conduit runs: either, but confirm the grommet or gland is listed for conduit, not just round cable. Parallel power conductors have their own layout concerns covered in running parallel conductors through a steel enclosure.
Sealing limits of each system
A gland plate seals exactly as well as its worst gland. An oversized hole filled with a gland on a thinner cable leaks at the cable, not the plate. A frame seals at two lines: the grommet-to-cable lips and the frame-to-cutout gasket. A grommet hole 0.04 in (1 mm) larger than the cable leaves the lips unloaded and that slot weeps first in a hose test.
Both systems depend on a clean cutout. A hole burned with a torch or a rectangular cutout with slag and burrs will not let any gasket sit flat. Have the openings machined, either at the factory or by a shop that deburrs both sides. The cutout, gland and HMI window guide sets out the spacing and size rules.
What to specify on the order
Decide the split before the enclosure is ordered, because the cutouts differ: round holes for glands, one rectangular opening per frame. Lay both on the entry face with the cutout designer, which checks spacing and exports the layout for a quote.
Put this on the drawing:
- Face and orientation (bottom face, glands in rows, frame at one end) and center positions of every hole from two edges
- Hole diameters matched to the gland threads you will use, with thread type noted, NPT or metric
- The frame cutout: width and height to the frame maker's cutout drawing, plus corner radii if required
- Spare positions: two undrilled grid spots or one empty frame slot per planned growth
- Gland plate separate or drilled in the enclosure wall, and material, 304 or 316L
- A drain or weep provision where the design allows it
For a worked size: a 16 x 16 x 6 in 304 stainless wall-mount enclosure takes an eight-gland plate row plus one compact frame on the bottom face. A 24 x 24 x 8 in wall-mount enclosure fits two frames plus a dozen glands with room to spare.
We machine every opening from one piece of stainless in the grade you choose, so the entry face arrives ready for glands and frames with no field cutting. Custom enclosures are delivered in 10 business days, counted from your approval of the drawing. If your cables are mostly pre-terminated, also read how waterproof panel-mount connectors can replace the whole entry question for small signal counts, and the custom enclosure specification guide for the full order checklist.
Enclosures in this article
| Enclosure | Material | Outside H x W x D / display | Rating |
|---|---|---|---|
| 16 × 16 × 6 in | 304 stainless | 16 x 16 x 6 in | Rated NEMA 4X / IP66 by the manufacturer; not UL listed |
| 24 × 24 × 8 in | 304 stainless | 24 x 24 x 8 in | Rated NEMA 4X / IP66 by the manufacturer; not UL listed |
Questions
Can I pass a cable with a molded connector through a gland plate?
Only if you drill an oversize hole and deal with the connector separately, which usually means losing the seal around that hole or adding a split grommet anyway. A gland plate is meant for bare cable ends that get terminated inside the panel. If the connector stays on the cable, a split cable entry frame or a dedicated connector-sized cutout is the right hardware.
Do split cable entry frames seal as well as glands?
Good frames with the correct grommet sizes are commonly rated to IP66 under IEC 60529 by their manufacturers. The weak point is a grommet that is too big for the cable, which leaves the seal lips unloaded. Match each grommet hole to the actual cable diameter and the frame seal to a flat, clean cutout, and the frame holds up in washdown and outdoor panels.
Can I add a cable entry frame to an enclosure that already has cables installed?
Yes, that is the main reason split frames exist. The frame and grommets come in halves, so you build them around the existing cables and close the frame in the cutout. You still need a clean rectangular cutout of the frame size, so the enclosure face must be drilled or cut before the cables are pulled, or an unused blank area used.
Should the entry face be the bottom of the enclosure?
Usually yes. Bottom entry keeps water from running into the seal, and a drip loop keeps it off the grommets. Side entry is acceptable with drip loops, and top entry is the last choice. Bottom conduit entry into a floor-mounted NEMA 4 enclosure covers the layout rules.
How do I order a custom enclosure with both entry types?
Send a drawing that shows each cutout's center position, hole diameters for glands, the rectangular frame cutout with frame make and model, and face orientation. We machine the openings from one piece of 304 or 316L stainless, and delivery is 10 business days from your approval of the drawing.
