Terminology
Shroud, boot, cover-up, cap or guard — what the words actually mean
A busbar joint under 2.00 mm of moulded PVC at 12 kV is a shroud in Mumbai, a boot in Chicago and a cover-up on the pole outside the substation fence.
Six words in this trade point at one class of part, and a single datasheet will happily use two of them. The PVC busbar part is published as a busbar insulating shroud and called a connection shroud in its own body copy. The moulded wildlife part is published as an electrical insulating boot / shroud, with the slash doing the work. Neither naming is careless: both words reach a real buyer.
So this is not a taxonomy. It is the habit of three regions and two industries, and no standard arbitrates it. What does arbitrate is a physical question you can settle by looking at the part: does it come off again, and what has to happen to the circuit first. Sort the six words on that and they stop overlapping — which also means an enquiry saying shroud and one saying sleeve should never come back with the same quotation.
The six words, one part each
- Shroud
- A moulded shell fitted over an already-assembled connection — a bolted joint, a tee, an elbow, a bushing stalk. It is sized by the geometry of the connection, not by one diameter, and it arrives complete with its fasteners. Wall thickness is the figure that tracks voltage on the PVC range: 1.25 mm at 3.3 kV, 2.00 mm at 12 kV, 2.50 mm at 18 kV, 3.00 mm at 24 kV and 4.50 mm at 38 kV, at 16 kV/mm min. (ASTM D149).
- Boot
- The same object named from the interface it is pulled onto rather than the connection it hides — a bushing, a separable connector, a termination stalk. North American switchgear practice and every harness shop use boot for all of it, which is why a boot search returns aerospace parts next to medium-voltage ones. Ask whether it is moulded rubber or heat-shrunk; that one question decides re-entry.
- Cover-up
- The North American utility word for the outdoor part — what a crew installs over a conductor, a jumper, a cutout or a bushing to take a clearance problem off a feeder. The bus and bushing covers here (GPFIC) are the cover-up half: UV-stable, track-resistant, field-trimmed at the entry and exit holes, re-enterable at the next maintenance visit.
- Cap
- A cap closes a cut end; it does not cover a middle. BUSCAP goes over the end of a live bar from GBC1 (15 × 5 mm) to GBC18 (200 × 12 mm) at 12 kV/mm min. (ASTM D149). Termicap closes a crimped cable terminal across TCV 12 to TCV 3251, and Termicover does the flat-tab version in GTIC-1 to GTIC-3. If the metal carries on past the part, it is not a cap.
- Sleeve
- Continuous tube that recovers onto the bar and then stays there. Sleeving is ordered on recovered internal diameter rather than bar width, and removal is destructive — a knife, then a new length. It is the one word of the six carrying no re-entry, which is why this site does not publish it and busbarsleeves.com does.
- Guard
- Wildlife-specific, and almost entirely North American: animal guard, bird guard, squirrel guard, raptor guard. It names the hazard rather than the part, so one moulded PVC shell is a shroud on a panel drawing and a guard on a distribution asset register. Insulshroud is the guard-shaped end of the range.
Which word means which part
The middle column is the one that actually sorts them. Everything else is dialect.
| Word | Goes over | Comes off again | Where you will hear it |
|---|---|---|---|
| Shroud | An assembled connection: joint, tee, elbow, bushing stalk | Yes — undo the fasteners | UK, India, Gulf; switchgear and panel work |
| Boot | The bushing or termination interface it is pulled onto | Rubber yes, heat-shrunk no | North America, aerospace, cable jointing |
| Cover-up | A conductor, jumper, cutout or bushing on a live outdoor asset | Yes — that is the point of it | North American utility and line crews |
| Cap | A cut end: bar end, crimped terminal, cable end | Yes on a push-on PVC cap | Everywhere; the least ambiguous of the six |
| Sleeve | A continuous run of bar or conductor | No — cut it off, fit a new one | Panel builders and switchgear OEMs |
| Guard | Whatever the animal is standing on or landing across | Yes | North American distribution asset teams |
Type the word your region uses, then translate
A reader searching one dialect will not find the part under the other.
- UK, Indian and Gulf specifications say shroud for the part inside the panel and line cover for the part on the pole, often on one drawing.
- North American utilities say cover-up for that outdoor part, and switch to animal guard or wildlife guard the moment a bird or a squirrel is the reason for fitting it. The part number does not change; the asset register field does.
- European bushing practice uses neither word. EN 50180 and EN 50181 govern the bushing and its plug-in mating part, so the drawing says bushing and plug-in connector, and whatever goes over the top of them stays unnamed.
- Aerospace and defence harness work says boot for the lot, sized against a military insulation-sleeving specification rather than a switchgear one — which is why a boot search mixes airframe parts with 36 kV parts.
"Gland shroud" is the same word doing a different job
A cable gland shroud is none of the six above. It is a cover over the body of an assembled gland where the cable passes into an enclosure, and what it is fighting is weather, dust and corrosion at the entry — not phase-to-earth clearance across a connection.
This site does not publish that part, its sizes or its datasheet, and will not pretend to. The heat-shrinkable entry gland, its three-part construction and its full selection chart sit on anodecap.com, which holds the source document.
"Shrouding" is a job; a "shroud" is a part
The gerund and the noun are typed by two different people wanting two different answers. Someone searching shroud wants a part, a size and a code. Someone searching shrouding wants a method: which connections inside a switchboard get covered, in what order, how many parts that comes to for one cubicle, and whether the board has to be dead throughout.
The second is a scope of work, answered on shrouding a switchgear panel or a transformer terminal box rather than here.
What the colours are for
Insulshroud is held in standard sizes in grey, red and black. Termicap, Termicover, BUSCAP and the moulded shrouds are all offered in custom colours, with new design moulds quoted inside a week.
None of those colours is a voltage rating. Colour here is phase and circuit identification, chosen by the panel's own scheme so an engineer can tell one circuit from the next through a cubicle door. A red shroud on an 11 kV connection is red because a drawing said red, not because red means 11 kV anywhere. The figure that genuinely moves with voltage is wall thickness.
None of the six makes a live part safe to touch
Every part on this page belongs to what the manufacturer itself calls insulation enhancement, and enhancement is doing honest work there. What the datasheets publish is a material property measured on a specimen — 16 kV/mm min. (ASTM D149) on the PVC busbar shroud, 20 kV/mm min. (ASTM D149) on the polyolefin line cover, no tracking or erosion up to 3.25 kV for 20 min (ASTM D2303). That is not a touch-protection class, and none of these parts is specified with one. Fit them so a bird, a branch, a tool or a rodent cannot bridge a gap — never so a person can work closer, and never in place of isolation and earthing.
If you came here for the part, not the word
Six words, and four of these sit on other properties because the source document does.
- Insulating shrouds over an assembled connectionGeometry, fasteners, thickness by voltage, and what re-entry costs.
- Terminal caps and terminal coversTermicap TCV and Termicover GTIC over crimped tabs and flat terminals.
- Insulator covers and bus connection cover-upsGPFIC covers, field-trimmed at the entry and exit holes.
- Animal, bird and wildlife guardsThe guard half, and which asset each one goes on.
- "Cable shroud" and "wire insulation cover"The other vocabulary page: four parts under two search terms.
- Reading a cover datasheetWhich printed numbers decide anything, and which are decoration.
- Busbar sleeving and the BUSBOOT shroud — busbarsleeves.comSleeves sized in millimetres, plus the BUSBOOT shroud range.
- Bushing boots and reusable insulating boots — cablebreakoutboots.comThe rubber boots that come off and go back on.
- Heat shrink tubing — shrink-tube.comIf it recovers onto the metal and stays, it is tubing, not a cover.
Send the connection, not the word
A photograph of the joint with a rule laid across it, the bar or conductor dimensions, the voltage class, and one line on whether it has to come off again for inspection.