ABB UC Series Maintenance Guide

Recommended practices
ABB recommends careful consideration of the following
factors when installing on-load tap-changers:
Before you install or commission a unit, make sure that the
personnel doing the job have read and fully understood the
installation and commissioning guide provided with the unit.
To avoid damaging the unit, never exceed the operating limits
stated in delivery documents and on rating plates.
Do not alter or modify a unit without first consulting ABB.
Follow local and international wiring regulations at all times.
Use only factory authorized replacement parts and
procedures.
Safety warnings
The following warnings and notes are used in the manual:
WARNING
WARNING indicates an imminently hazardous
situation, which if not avoided will result in death or
serious injury. This signal word is to be limited to the
most extreme situations.
WARNING also indicates a potentially hazardous
situation, which if not avoided could result in death or
serious injury.
CAUTION
CAUTION indicates a potentially hazardous situation,
which if not avoided may result in minor or moderate
injury. It may also be used to alert of unsafe practices.
CAUTION may also indicate property-damage-only
hazards.
INFO provides additional information to assist in
carrying out the work described and to provide
trouble-free operation.
Safety precautions
WARNING
The Maintenance guide should be read and
understood before any work is started, and the
procedures in this document should be followed at all
times.
WARNING
Before any work is carried out on the tap-changer:
Make sure that the transformer is disconnected and
that grounding is properly conducted. Obtain a signed
certificate from the engineer in charge.
WARNING
Before carrying out work on the tap-changer, put
the LOCAL/REMOTE switch on the motor-drive
mechanism to position 0. It is also advisable to shut
the door of the motor-drive mechanism and pad lock
it when work is carried out on the tap-changer. The
key should be kept by the operator. This is done
to avoid an unexpected start of the motor-drive
mechanism.
WARNING
Before starting any work inside the motor-drive
mechanism, the auxiliary power must be switched off.
NOTE: The motor, contactors and heating element
may be energized from separate sources.
WARNING
In no case should any person go down into the
diverter switch housing. The cleaning of the diverter
switch housing should be carried out by using
brushes and rags and by flushing with oil.
CAUTION
Approval should be given for inspection as well as for
operating the on-load tap-changer.
CAUTION
ABB recommends that only maintenance engineers
trained by ABB carry out contact replacement.

ABB UC Series Specifications

General

Brand	ABB
Model	UC Series
Category	Industrial Equipment
Language	English