Procedures
Fitting covers, shrouds and caps: four procedures and one removal
A wrap profile closes with a roller tool. A silicone cover closes by hand at 0 °C. A moulded shroud closes on the fasteners it came with. A heat-recovered cap closes at 125 °C.
What is published below, and what this site reconstructed
One of these five sequences is the manufacturer's own: the torch procedure, printed step by step on the Polecap and Dock Pile Cap installation sheets and reproduced without addition. The other four are assembled from single lines scattered across the product sheets, and every step that is our reasoning rather than the manufacturer's instruction says so. Where a part ships with its own leaflet, that leaflet governs.
The closure tells you which procedure you are running
A moulded PVC shroud over a 12 kV bolted joint is 2.00 mm thick and arrives complete with its own fasteners. That is one of exactly four closures in this catalogue, and the closure — not the voltage, not the material, not the shape of the metal underneath — is what fixes the method.
Nothing in the first three procedures below uses heat, and nothing in the fourth uses a fastener. The fifth is removal, which no sheet in the pack writes out. It gets its own section because whether a cover survives coming off decides what a covered connection costs over twenty years, far more than the price of the part does.
Procedure 1 · Wrap-around polyolefin cover (GOC), with the split tube tool
Non-tracking cross-linked polyolefin, five sizes, 30 metre rolls. 20 kV/mm (min., ASTM D149), −45 to +105 °C (IEC 216), no tracking, erosion or flame failure up to 3.25 kV for 20 min (ASTM D2303).
Take the code from the measured diameter
GOC 1 accepts up to 10 mm across the strands, GOC 1A up to 15 mm, GOC 2 up to 22 mm, GOC 3 up to 28 mm, GOC 4 up to 38 mm. Every size ships 30 metres to a roll, so the run length is a roll count. The profile in detail.
Anchor the tool once and work the cover past it
The manufacturer's wording is that the Split Insulation Tube Tool remains stationary at a single location. Read that as an access constraint: one set-up serves one run, and plant, anchor and crew get placed around that point. The sheet names no alternative to the tool.
Check whether your size closes onto mastic
GOC is supplied with mastic for high-voltage applications, and the GOC 4 section is drawn with sealing mastic already in its receptacle. On that size the closure is a bedded joint — latch it the full length and treat it as a one-way fit, not a clip.
What the GOC sheet leaves out
No installation temperature is published. The −45 to +105 °C figure is continuous service (IEC 216), not a working range for a roller head on a cold morning. The silicone sheet publishes a low-temperature line; this one does not. Winter work is a written question.
Procedure 2 · Self-locking silicone and trimmed cover-ups, both by hand
GSOC self-locking covers, GSIOC interlocking covers, and the GPFIC pre-formed connection covers. No tool anywhere in this group, and two of the three are meant to be opened again.
Fix the class, then fit the cover where it stands
GSOC-M runs to 12 kV at a 2.0 mm wall, GSOC-H to 36 kV at 2.7 mm, GSOC-H3 to 36 kV at 3.0 mm, GSOC-EH to 765 kV at 5.0 mm. Wall is the only variable that moves; the conductor bands repeat unchanged, 15 metres to a roll. GSIOC interlocks, to 33 kV. Both ranges.
Cold fitting is stated, with one qualification
The GSOC table carries a row reading Low Temp. Install at 0 °C, value installable without difficulty. The test-method column against that one row is a dash while every other row names an ASTM method. Quote it as a manufacturer's statement, not a test result.
Trim the cover-up at ground level
GPFIC covers are trimmed at the entry and exit holes to the dimensions the job needs. GPS 1099 comes with a 100 mm bottom opening, GPS 1178 with 40 mm left and bottom, GPS 1167 with 90 mm left and right plus 100 mm bottom, GPS 1158 with 50 × 10 mm on the busbar side, GPS 1165 with no opening at all. Cut below, carry up a part that fits. The GPS codes.
Tape is an addition, not a rescue
Self-fusing silicone tape, 63.5 mm wide and 0.76 mm thick, is published as an option over the cover, quantity depending on conductor size. Our rule, not the manufacturer's: it goes over a cover that already fits and closes no gap left by the wrong size.
Procedure 3 · Moulded shrouds, caps and covers, closed on their own fasteners
Mouldings for an assembled connection — joints, tees, elbows, crimped tabs. Supplied complete with fasteners and stated to install, remove or replace in minutes.
Wall thickness answers to the class and nothing else
The PVC shroud is recommended at 1.25 mm for 3.3 kV, 2.00 mm for 12 kV, 2.50 mm for 18 kV, 3.00 mm for 24 kV, 4.50 mm for 38 kV — 16 kV/mm (min., ASTM D149), −20 to +115 °C (IEC 216), UL 94-V0, UL File E335936, tested to ANSI C37.20.2 to 36 kV. A thin part on a high class is a purchasing error. Shrouds by class.
Close it so the overlap is still an overlap
The sheet credits the shroud's extra flash-over margin to an overlapping design, and the supplied fastener line holds that lap shut. Our reasoning for not substituting a tie: closing at one point rotates the lap open further along, and the claimed margin goes with it.
Seat it on the geometry — do not let it bridge
This check is ours, not the manufacturer's. A moulded cover is drawn around a shape. Fitted so it spans high point to high point instead of following that shape, it closes an air void into the middle of the connection. Offer it up dry and look at where it touches.
Terminal parts are held by shape, not by fixings
Termicover has recesses on the tab shoulders that keep the terminal seated and a sleeve that keeps dust out of the cable end, GTIC-1 to GTIC-3, 12 kV/mm (min., ASTM D149). Termicap pushes over the crimped wire-end terminal and colour-codes it, TCV 12 to TCV 3251, 16 kV/mm. Both.
Procedure 4 · The torch, for heat-recovered parts
The manufacturer's own sequence, from the Polecap and Dock Pile Cap installation sheets. Nothing in the three procedures above recovers with heat and none of those sheets carries a torch instruction, so this applies only where the part was supplied in an expanded form.
Prepare the surface before the flame comes out
Cut the end straight and even if it is not already. Clean and de-grease every surface that will come into contact with the sealant. The sheet puts both ahead of the heat, not after it.
Set a soft blue flame with a yellow tip
Propane is the stated preference, butane is accepted. Pencil-like blue flames are to be avoided — the sheet's own wording — and the flame is kept moving continuously so the material does not scorch.
Recover above 125 °C, starting at the closed end
Supplied expanded, the part returns towards its original dimensions above 125 °C and conforms to the object underneath. Work back from the closed end; adhesive showing at the ends is the finish signal the sheet gives. The same 125 °C figure appears on the manufacturer's heat-shrink shroud sheet (IEC 216).
Let it cool before it takes any load
A properly installed part is smooth and conforms to what it covers. Allow it to cool fully before applying any mechanical strain — on the sheet, and the step that gets skipped when the next set is waiting.
Procedure 5 · Taking a cover off without destroying it
The site's own sequence. No sheet in the manufacturer's pack writes out a removal method, though three of them state plainly that the part can be removed.
Find the removal sentence before you touch anything
The PVC shroud is stated to install, remove or replace in minutes and to be easy to install or remove as often as required. The moulded insulating shroud says the same, safely and easily. The GPFIC cover is stated to be re-entered for other maintenance needs and then reused. The GOC wrap and the GSOC cover say nothing of the kind — programme those two as cut-and-replace.
Open the fastener line in the order it was closed
Record the closing order at first fit and keep it with the panel drawing. Our reason: the lap on a moulded shroud is directional, so releasing it from the wrong end drags the overlap against itself, and that is where a reusable part tears.
Cut on the trim line that already exists
A cover-up was cut to a measured entry and exit at first fit, and anything cut into it on the way off is permanent. If a hole has to be enlarged to clear a bigger lug, the part is being modified rather than removed.
Inspect it off the structure, in daylight
Two states, both our reading rather than a published criterion. The surface has tracked or eroded — the carbon path or pitting the ASTM D2303 schedule exists to predict. Or the material has cracked or taken a permanent set, so it will not seat on the geometry again. Either makes the part scrap. What each test method predicts.
Date the inside face before it goes back
A refitted cover is a different item from a new one and nothing on it records that. A date on the inside face gives the next inspection a history, and it costs one marker pen.
Not published — ask the manufacturer
Three sheets state that the part can be removed and refitted. None states how many times, what to inspect before it goes back, or the condition at which a removed cover should be discarded. There is no published reuse count and no published scrap criterion anywhere in this pack — the two scrap states above are this site's reading of the test schedule. If a reuse limit has to enter a maintenance policy, put the question to Gala Thermo Shrink Pvt. Ltd. in writing.
What this does not do
Five procedures, and not one of them is a work method.
- None of this is a live-working method statement. Every procedure above assumes the isolation, the earthing and the permit already exist. Where a cover goes onto an energised conductor the method belongs to the utility that owns the line.
- Fitting a cover does not make anything safe to touch. A retrofit cover on bare metal is insulation enhancement against momentary contact and nothing more. Read that difference first if the job is on an overhead line.
- It does not replace the leaflet in the box. Where a part is supplied with its own installation sheet, that sheet governs.
- It does not cover heat-shrink sleeving or tape on a flat bar. Different geometry, different exercise, and the datasheets sit elsewhere in the manufacturer's range.
- It does not rescue a wrongly sized part. No technique above saves a cover picked off the sq.mm column when nobody measured across the strands.
The part each procedure belongs to
- Wrap-around polyolefin line cover (GOC)Procedure 1 — five sizes and the tool that closes the profile.
- Silicone line covers, GSOC and GSIOCProcedure 2 — four classes to 765 kV, fitted with no tool.
- Insulator covers and bus connection cover-upsProcedure 2 — the GPS-coded parts that are trimmed and re-entered.
- Insulating shrouds for an assembled connectionProcedure 3 — wall by voltage class, fasteners supplied.
- Termicap and TermicoverProcedure 3 — held on by the shape of the terminal.
- How to read an insulating cover datasheetWhich rows decide a fit and which are laboratory conditions.
Send the dimension and say whether it has to come off again
Give the conductor diameter or bar section, the voltage class, the part code if there is one, and whether that point has to be re-entered for thermography or a re-torque. The last of those changes the answer more than the first three. The goods are manufactured by Gala Thermo Shrink Pvt. Ltd., Mumbai.