Most revisions to a covered conductor order trace back to data that was missing at enquiry stage: a span that turned out longer than assumed, a crossing nobody listed, a pole type that was never checked. A short survey avoids them. Use the checklist below on each feeder section, then carry the answers into the tender specification checklist or an enquiry to APAR.
Line data
| Record | Why it matters |
|---|
| Nominal voltage and system earthing | Decides the voltage class. APAR covered conductor is offered at 11, 22, 33, 66, 110 and 132 kV. |
| Existing conductor type and size | Sets the starting point for the replacement size, within the 100 to 400 mm² range offered. |
| Span lengths, longest and typical | Drives the choice of conductor core and the sag check. |
| Pole type, strength rating and condition | The covering adds weight compared with a bare conductor of the same size. |
| Cross-arm and insulator type | Covered conductor is designed to be installed without changing poles, cross-arms or insulators in the same span, which holds only if these are sound. |
| Number of circuits and phase arrangement | Affects accessories and clearance checks. |
Route and crossings
| Record | Why it matters |
|---|
| Vegetation type and height beside the line | Tree and creeper contact is the usual reason to move to covered conductor. See tree contact on 11 kV and 33 kV feeders. |
| Forest, wildlife or plantation sections | Marks where animal and bird contact is likely. |
| Road, rail, river and canal crossings | Each crossing has its own clearance and approval requirements from the owner of the asset. |
| Dense housing or built-up sections | Marks where narrow corridors and public safety weigh most. |
Environment
| Record | Why it matters |
|---|
| Distance from the coast, industrial emissions, dust | Salt and pollution affect the covering surface and the choice of core. |
| Wind exposure and storm history | Conductor clashing is a wind-driven fault. |
| Flood or waterlogging risk | Affects drum storage and pole base checks. |
Fault and load history
| Record | Why it matters |
|---|
| Trip log for the last two years, split into transient and permanent | Shows which spans cause the outages. Transient trips that clear on reclosure often point to contact faults. |
| Weather on the day of each trip | Separates wind-driven and storm faults from the rest. |
| Peak load current and ambient temperature | Checked against the covered conductor operating temperature of up to 95°C, or 105°C for AL59 ACS. |
| Fault level at the source end | Needed for the protection and arc protection design. |
Constraints on the work
Note the permitted outage windows, access for drum delivery and stringing equipment, and any section that cannot be shut down. Delivery planning is covered in the drum handling and site receipt checklist.
Sending the survey to APAR
Share the completed checklist with the enquiry on the covered conductor page. Technical particulars, test certificates and samples are available on request.
