Scope
These instructions cover the installation, operation and mainte-
nance of Siemens type GM metal-clad switchgear assemblies,
using vacuum horizontal drawout circuit breakers. The equipment
designs described in this manual include indoor, Shelter-Clad
walk-in aisle outdoor, and non-walk-in outdoor configurations
for application up to 15kV. A typical indoor switchgear assembly is
shown in
Figure 1
. All diagrams, descriptions and instructions
apply to all the above classes and designs unless noted otherwise.
Standard construction details of the switchgear, auxiliary
equipment and necessary accessories are given in the appropri-
ate sections. Special mechanical and electrical devices, furnished
in accordance with purchase order requirements, are covered by
supplementary instructions submitted with this instruction book.
The equipment furnished has been designed to operate in a
system having the circuit capacity specified by the purchaser.
If for any reason the equipment is later used in a different system,
or if the short-circuit capacity of the system is increased, the
momentary rating of the switchgear, the interrupting capacity
of the circuit breakers and the bus capacity must be checked.
Failure on the part of the user to receive approval of intended
changes from Siemens may cause voiding the warranty.
General Description
The switchgear described in this manual is of the metal-clad
type, as defined in ANSI C37.20.2. All parts are completely
enclosed within grounded metal barriers. Secondary control
devices and primary circuits are isolated from each other by
shutters or barriers. Primary bus and joints are completely
encased with insulation materials to suit the voltage class of
the equipment.
Siemens switchgear carries a type designation, or class, as
shown in
Table 1
. These designations may appear on draw-
ings and familiarity with them will simplify communications
with the factory.
Indoor equipment is arranged with upper and lower compart-
ments in the front of the equipment. Generally, either or both
compartments may contain a drawout circuit breaker, located
behind a front panel which is used for relays, instruments, and
similar devices. The front panel may be opened to provide
access to the circuit breaker or interior auxiliary equipment,
such as voltage transformers, or control power transformers.
Typical indoor switchgear is shown in
Figure 1
.
Table 1.
Switchgear Designation
Shelter-Clad outdoor equipment consists of indoor equipment
enclosed in a weather resistant housing complete with an illumi-
nated, walk-in aisle. Circuit breakers can be moved inside the
aisle and control devices checked without exposure to the ele-
ments.
Non-Walk-In outdoor switchgear consists of indoor equipment
enclosed in a weather resistant housing complete with a gas-
keted outer door over the inner front panels. Circuit breakers
can be moved outside of the cubicles with the use of a lift
truck or similar handling device. Non-Walk-In outdoor equip-
ment is used where it is felt that an enclosed service aisle is
unnecessary, or space does not permit its use.
General Description
4
DESIGN
TYPE
Indoor
GM
Shelter-Clad Single Aisle Outdoor
SGM
Shelter-Clad Common Aisle Outdoor
SGM
Non-Walk-In Outdoor
OGM
