SWA cable gland termination at the enclosure step by step

Short answer: terminate BS 5467 steel wire armoured cable in a two-part brass gland — the union nut plus the cone ring — so the gland clamps the armour and earths it through the body. Crimping the armour strands into a lug leaves the cable neither fixed to the enclosure nor sealed; it fails both jobs at once. Fitted in the right order — shroud on first, then the sheath strip, then the armour cut — one gland takes 5-10 minutes. In the wrong order the same gland costs an hour or two. The usual culprit: the nut and cone went on after the sheath came off. For a cable of 14.1 mm overall diameter the gland lands on the 20 mm size, and the hole is 20 mm [0.79 in].

Why the armour goes in a gland, not a lug

A lug answers the wrong question. The armour is not a core to land on a terminal; it is the cable's strength member, its second earth path and part of keeping water out. A two-part gland does all three jobs in one fitting. The cone and the union nut clamp the armour wires, so the cable hangs from the wall instead of from its cores. The gland body carries that clamp through to the enclosure metal for the bond. A CW type adds a seal that grips the outer sheath against rain and hose wash; a BW type grips the armour only and belongs on a dry indoor wall.

Take the CW anywhere water runs, and make sure its outer seal actually sits on the cable's outer sheath — the contact rule is spelled out in why a gland seal must reach the cable's outer sheath. The hardware answers to different words on different sides of the Atlantic. US specifications often say armoured-cable fitting or cord grip where a UK drawing says gland, and the gland versus cord grip naming guide sorts out which word a specification means. New to the parts themselves? The fundamentals are in what a cable gland is and does.

What you need

Lay the parts out before the cable is cut; the strip goes fast only when everything is on the bench.

We cut the holes you order into the wall at the factory. The cutout designer lays every entry on the face, checks the spacing between gland bodies and sends the layout with the quote; the finished box is delivered in 10 business days, counted from drawing approval on custom work. A wall that arrives with its holes cut keeps the gasket faces untouched and turns the make-off into a bench job. If a hole has to go in on site, how to cut a hole in a stainless steel enclosure walks the punch, the hole saw and the file work.

Sizing the gland for a 4-core 2.5 mm² cable into a 20 mm hole

Inputs, with their sources. Cable: 4-core 2.5 mm² BS 5467 XLPE/SWA/PVC; the published BS 5467 tables put the overall diameter at 14.1 mm with one maker and 12.6 mm with another. Entry: a 20 mm gland body, so the cutout is 20 mm [0.79 in]. Bend: BS 5467 sets the minimum installation bend for armoured cable at 6 x the overall diameter. Bench setup: a 12 in [300 mm] core tail and an 18 in [450 mm] sheath strip, with the hose clip 2 in [50 mm] above the sheath edge. Pace: 5-10 minutes per gland for a crew that strips in order, against 1-2 hours per gland when the make-off starts with a restart.

The rules in words. The gland size follows the measured overall diameter through the gland maker's selection chart. The hole follows the gland's entry thread, not the cable. The cable's last bend before the wall stays outside the installation minimum, and the strip leaves enough bedding for the cone and enough tail for the terminals.

Arithmetic.

• Straight approach to the gland: 6 x 14.1 mm = 84.6 mm, so keep about 85 mm [3.3 in] of straight, supported cable before the cone.
• Working room inside: 18 in of sheath strip less the 12 in tail leaves 6 in [152 mm] of armour and bedding between the sheath cut and the core ends, the region the cone, the fanned wires and the body have to share.
• Reel check: 14.1 mm against 12.6 mm is a 1.5 mm spread, enough to cross a boundary on a gland chart. Measure the delivered reel and take the gland row from the measured number; matching a gland to a cable by diameter is the whole subject of the gland clamping range guide.
• Panel time, six entries: 6 x 5 min to 6 x 10 min = 30-60 minutes in the right order, against 6 x 1 h to 6 x 2 h = 6-12 hours of restarts. The right order saves 5.5 to 11 hours across the panel.

Result and decision. The 14.1 mm cable sits in the 20 mm gland row on the standard BS 5467 charts; the hole is 20 mm [0.79 in]; the straight approach is 85 mm [3.3 in]. Threshold to work to: a gland that passes 10 minutes is telling you the cone rides the bedding instead of pinching the wires. Back the union nut off, re-fan the wires evenly around the cone and tighten again.

Cutting the hole and setting the body

Punch or hole saw the 20 mm [0.79 in] cutout, deburr both edges and clear the swarf off the wall before the body goes in. The body's sealing washer needs flat, bare metal.

Set the earthing nut on the entry thread, or the banjo under the body's inner locknut, so the gland body bonds to the enclosure. On a painted steel box, point the serrated teeth at the paint. NEC 250.12 requires nonconductive coatings removed from threads and contact surfaces at grounding and bonding connections, and the teeth do that work for you. Entry threads come in metric M, PG and NPT; the thread decides the hole and any sealed adapter after it, and the G-thread versus NPT guide covers the choice.

On a thin stainless wall a gland thread can come up short for the union nut; a threaded adapter for a thin enclosure plate restores the engagement without touching the seal. Where the fly lead lands inside is part of the whole bonding scheme, laid out in the grounding and bonding guide.

Fitting the gland, step by step

Make the panel dead and prove it dead before the first core lands.

1. Slide the shroud over the cable end and park it well back past the sheath cut. It cannot go on afterwards.
2. Cut the cable to length so the cores reach their terminals with a 12 in [300 mm] tail and the gland lands on the wall without carrying the cable's weight.
3. Mark the outer sheath 18 in [450 mm] from the cable end, cut square and pull the sheath off without nicking the bedding underneath.
4. Slide the union nut down the cable and park it at the sheath edge, threaded end toward the wall.
5. Fan the armour wires and slip a hose clip 2 in [50 mm] above the sheath edge; tighten it to hold the bundle square.
6. Cut the wires off square and equal, then straighten each one by hand.
7. Strip the inner bedding back to expose the cores for the tail.
8. Slide the cone ring over the bedding from the cable end, cores through the bore.
9. Fan the wires evenly around the cone, every wire on its taper.
10. Screw the gland body into the 20 mm hole, washer flat, earthing nut or banjo in place for the bond.
11. Run the union nut down over the wire ends onto the body and tighten until the cone visibly pinches the wires. The wires must not turn with the nut.
12. Run the fly lead from the tag or earthing nut to the enclosure earth terminal. Bond the armour at the supply end when the armour does not carry fault current; that is the default. When the armour is the circuit protective conductor, bond both ends.
13. Push the bedding through so it shows inside the gland; a nick you can see today is a fault you never chase in year three.
14. Slide the shroud forward over the union nut and onto the sheath.
15. Cleat the cable within about 12 in [300 mm] of the gland and land the cores on their terminals.

Checks before you sign it off

• Grip: pull the cable hard by hand; the armour holds. If it slides, the cone is riding the bedding and the wires swim.
• Bond: measure from a scraped armour wire to the enclosure earth terminal. An open circuit fails; a reading well above the fly lead's own points to paint under the tag or a wire outside the taper.
• Bedding: it shows through the gland, and the core insulation is unmarked.
• Shroud: seated over the union nut and onto the sheath.
• Water path: outdoors, the cable dips below the entry before it rises to the cleat, so rain runs off before it reaches the seal.
• Support: the cleat carries the weight; the gland carries only the seal.

Mistakes that cost the earth path or the rating

• Armour in a lug: the strands are steel, the lug is sized for copper, the cable hangs on its cores and nothing seals.
• Gland one size large: the cone rides the bedding instead of the wires, so grip and bond fail together.
• A wire left outside the taper: the missed wire carries no fault current, and the rest sit loose in the cone.
• Bedding trimmed flush with the gland: the insulation nick hides inside the fitting and turns up later as an earth fault.
• Water with a straight run: rain tracks down the sheath into the union nut, and hose wash finds every gap in a BW fitting; the cable-side paths are covered in stopping water wicking through cable.
• An entry rated below the wall: the assembly takes the lowest rating fitted to it. Our 304 and 316L boxes are rated NEMA 4X / IP66 by the manufacturer; not UL listed, and a gland or adapter documented lower pulls the whole assembly down to its own rating. Installing a cable gland without losing the rating keeps the letters through the make-off.

Catalog dimensions to compare

Compare these catalog dimensions with your component layout. Open each enclosure for its rating, material and usable space, then check those specifications against your application.

Questions