Benefits of withdrawable switchgear and motor control centres

Ever since electricity was first transmitted and
distributed, there has been a need for switchgear. As
distribution systems evolved, this switchgear became
available in fixed and withdrawable forms. This evolution
continues, and the emergence of new technologies and
designs means that the “optimum” solution still changes
over time.
This paper compares the benefits of fixed and
withdrawable switchgear, taking into account the function
that the switchgear has to perform. The topics covered
include:
• Safety of personnel and processes,
• Total cost of ownership, including consideration of
factors like reliability, availability, cabling, switch room
size and process control connection,
• Operator friendliness: how easy is it to work with the
switchgear, and the complexity of the switching
protocols,
• The ease with which maintenance inspections and
measurements can be performed,
• The need for switchgear to be fit for purpose and to
be sufficiently robust to suit the application,
• Ease and speed of repair and ease of housekeeping
for spare parts,
• The need for high time-to-failure and the
consequences of failures.
The aim of this paper is to provide input for the panel
discussion comparing withdrawable and fixed switchgear
and MCCs, with the focus on usage of the switchgear and
its function within the total process, also taking into
account the newest technologies in switchgear and
network architecture.
It is intended to provide answers to questions like:
• Should fixed or withdrawable or something in
between be chosen?
• When is it best to choose fixed switchgear and when
is withdrawable the better choice?
Which applications require withdrawable switchgear?
• Which form of switchgear will be preferred in future?
Index Terms:
Fixed electrical switchgear or withdrawable electrical
switchgear