MAINTENANCE OF INSULATED AERIAL DEVICES AND OTHER EQUIPMENT USED FOR LINE MAINTENANCE

We provide a maintenance service for Insulated Aerial Devices for Live-Line Maintenance

Insulated Aerial Device Maintenance

In line with its policy of providing the most comprehensive solution to its clients, in 2018 Kolab added insulated aerial device maintenance to its range of services, in addition to dielectric testing of aerial devices, which it already provided. In charge of Kolab’s aerial device maintenance service is a line equipment repair and maintenance specialist with over 14 years’ experience. Soon our clients started to request maintenance of other equipment with hydraulic components, such as cable drum jacks, line stringing equipment, and power tools, suck as chainsaws or hotstick-mounted hydraulic cutters.

What is an Insulated Aerial Device and what purpose does it serve during live line maintenance?

An insulated aerial device consists of a fibreglass platform (bucket) mounted on an insulated lifting boom, itself mounted on a truck.

The upper boom consists of a fibreglass tube which provides the required level of insulation. Along its interior run hydraulic hoses filled with dielectric (insulating) oil, which enable boom and bucket movements, and levelling rods, which ensure that the bucket remains horizontal regardless of the boom position. The lower boom has an insulating fibreglass insert, designed to protect workers on the ground in the event of accidental contact of the boom elbow with a phase conductor or other energised part.

An aerial device is an elevating platform that allows linemen to approach the energised line conductors they will be working on. Its insulation provides a second layer of protection, in addition to the insulating gloves (for rubber glove work) or conductive suit (for barehand work) worn by the linemen.

Aerial devices are mounted on a truck of suitable size and features, allowing them to access the work locations. These trucks have outriggers which prevent overturning during lateral extension of the boom.

Why is regular maintenance of insulated aerial devices important?

It is an essential requirement for any industrial equipment to keep it in perfect operating condition to ensure its serviceability, as well as the safety of the workers.

For live line work, maintenance becomes critical, since any malfunction preventing linemen from moving away from an energised line, or any damage compromising the aerial device’s dielectric integrity, would represent a serious risk for the workers.

What are the main maintenance activities and at what intervals should they be performed?

Cleaning boom exterior and proper maintenance of boom outer surface. Repairing any damage (grooves, scratches, pitting, buffs, etc.) where contamination and moisture (a potentially conductive combination) may accumulate. Frequency: as and when required.
Hydraulic oil and filter replacement. Only dielectric oil must be used, to ensure the insulation of the aerial device. Frequency: once a year.
Check mechanical elements for play. Frequency: once a year.
Check leakage current cables and connections. This allows us to verify the aerial device’s insulating capability. Frequency: once a year.

Check proper performance of all aerial device functions, including boom lifting and lowering, rotation and bucket levelling, together with the various safety features. Frequency: once a year.
Lubricate all points specified by the manufacturer. Frequency: once a year.
Visually inspect and check tension of bucket levelling chains. Re-tension and clean, if required. Frequency: once every 5 years or according to manufacturer’s specifications.
Remove levelling chains, clean and check for excessive play. Frequency: once every 10 years or according to manufacturer’s specifications.

What are the main repair tasks?

Replacing deteriorated dielectric hoses
Repairing or replacing platform joystick (multi-functional lever)
Correcting play in mechanical elements
Repairing fibreglass surfaces (booms, covers and buckets) with epoxy filler and applying a coat of dielectric paint
Repairing leaks in cylinders, valves, etc.