General description
Type A bushings are designed for application on transformers.
Porcelain is used as the major insulation, and the single-piece
porcelain is bottom end connected to the apparatus to insulate
the conductor from the grounded mounting surface.
Type A bushings are available with voltage ratings from 1.2 to
34.5 kV. Bushings rated 600 amperes and lower have draw-
lead conductors which allow the bushings to be removed
without disturbing connections inside the transformer. Fixed
conductor bushings are available in current ratings through
18,000 amperes.
The fixed conductor bushings are center clamped with spring
washers or multiple spring mechanisms at the bottom end.
This construction provides a pressure tight seal and develops
maximum strength in the porcelain.
Safety information
Keep this document available to those responsible for the
installation, operating, and maintenance of the bushing.
The installation, operation, and maintenance of a bushing
present numerous unsafe conditions, including, but not limited
to, the following:
– High pressures
– Lethal voltages
– Moving machinery
– Heavy components
Specialized procedures and instructions are required and must
be adhered to when working on power transformers. Failure to
follow instructions could result in severe personal injury, death,
and/or product or property damage.
Additionally, all applicable safety procedures such as OSHA
requirements, regional and local safety requirements, safe
working practices, and good judgment must be used by
personnel when installing, operating, and/or maintaining such
equipment.
Safety, as defined in this document, involves two conditions:
– Personal injury or death
– Product or property damage (includes damage to the
bushing or other property, and reduced bushing life.)
Safety notations are intended to alert personnel of possible
personal injury, death or property damage. They have been
inserted in the instructional text prior to the step in which the
condition is cited. The safety notations are headed by one of
three hazard intensity levels which are defined as follows:
– Danger - immediate hazard which will result in severe
personal injury, death, or property damage.
– Warning - hazard or unsafe practice which could result in
severe personal injury, death, or property damage.
– Caution - hazard or unsafe practice which could result in
minor personal injury, or property damage.
This document contains general
procedures to be followed from the time
bushings are received until they are put
into operation.
Receiving and unpacking
When a bushing is received, examine any damage incurred
during shipment. Inspect the surface of the porcelain for small
breaks or cracks. If damage or rough handling is evident, file a
claim with the transportation company and immediately notify
ABB.
Exercise care in opening the shipping container to prevent
damage to the porcelain insulators. As each bushing is
Transformer components
Type A bushings
Instructions for installation, maintenance, and storage