Most damage to a covered conductor happens before stringing starts. A drum dropped from a truck, rolled the wrong way across rough ground or left unsealed in the rain can damage the covering or let moisture into the conductor, and the defect may not show until the line is in service. The covering is what the utility is paying for, so the drum deserves the same care as the conductor on it.
Site receipt checklist
| Check | Accept when |
|---|---|
| Drum identification | Drum number, conductor type, size, voltage grade and length match the delivery note and purchase order |
| Test documents | Routine test certificates are received for each drum, cross-referenced by drum number |
| Drum structure | Flanges unbroken, battens or lagging intact, spindle holes clear |
| Conductor ends | Both ends sealed with end caps and secured to the drum |
| Outer layers | No visible cuts, crushing or nail damage on the outermost turns |
| Marking | Printed marking on the covering is legible and matches the order |
Record any damage on the delivery note before signing, with photographs, and keep the drum aside until it has been assessed.
Unloading
Drums should be lifted with a crane or forklift using a spindle through the centre hole, or lowered down a ramp under control. They should never be dropped from the vehicle onto the ground or onto tyres. A forklift should lift under both flanges, never against the conductor or lagging.
Rolling and storage
- Roll a drum only in the direction of the arrow painted on the flange, so the turns do not loosen.
- Store drums standing on their flanges on firm, level, well-drained ground, chocked so they cannot roll. Do not lay them flat.
- Keep end caps in place throughout storage. Replace any cap removed for inspection, and reseal a cut end the same day.
- Store away from fire risk, chemical spillage and vehicle traffic, and keep enough space between drums for lifting equipment.
- Use stock in delivery order, and keep the test certificates with the drum records.
At the stringing site
Mount the drum on a stand with a brake so the conductor pays out under controlled back-tension and does not touch the ground. Inspect each section as it leaves the drum. Stringing practices, clamps and connectors that protect the covering are covered in the MVCC accessories and installation guide, and the clauses to include in a purchase specification are in the covered conductor tender checklist.
APAR’s covered conductors for 11 kV to 132 kV, in AAAC, ACSR, ACSS and AL59 ACS, are listed on the covered conductor product page.