GE Industrial Solutions Power Equipment Buildings User Manual
Page 6
Electrical Equipment Centers
Application Considerations
Page 6
Most major switchgear suppliers offer a line of sheltered aisle in single-row or double row arrangements that typically
comply with NEMA 3R requirements for outdoor installation. Single-row installations consist of a line-up of outdoor
switchgear adjacent to a weatherproof walk-in aisle. The overall design provides weather protection and good
economy of space, but is limited in application flexibility and room of auxiliary equipment. The below table provides
a more detailed comparison of equipment center construction and application as an alternative to NEMA 3R Sheltered
Aisle Switchgear enclosures.
Table 3
Equipment Center
Sheltered Aisle Switchgear
Major electrical
Equipment
No Difference
No Difference
Sourcing
One Manufacturer is responsible;
enclosure is flexible and can
accommodate various equipment
Separate enclosure must be
sourced for each type of electrical
equipment
Design and Engineering
Complete package designed and
engineered by one manufacturer
Purchaser must design and
engineer
Foundation
Minimum foundation, i.e.,
curb type or pier type
Usually requires full slab
foundation with relatively large
stem walls and footings
Base
Self-supporting, allowing all
equipment to be factory leveled
before shipment
Purchaser provides channel base
and grouting for leveling all
equipment
Internal wiring
Factory wired complete with
wiring schematics
Job-site interconnection of
control wiring as well as major
equipment
External connections
Easily adaptable to overhead or
underground conduit systems
Slab floor mandates detailed and
exact conduit location; changes
are difficult
Testing
Unit is completely factory tested;
customer can complete many
pre-energization tests before
installation
Receiving, Handling
& Storage
Arrives in single shipment,
usually unloaded in one hour; can
be stored indefinitely as integral
unit, inherently
Equipment Center
Purchaser must provide for
receiving and storage multiple
units made at different times by
different suppliers.
Sheltered Isle Switchgear
Receiving, Handling
and Storage (Cont.)
Often times involves redundant
handling for storage, trucking to