USACE / NAVFAC / AFCESA / NASA UFGS-26 05 48.00 10 (October 2006)
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Preparing Activity: USACE Superseding
UFGS-26 05 48.00 10 (April 2006)
UNIFIED FACILITIES GUIDE SPECIFICATIONS
References are in agreement with UMRL dated January 2009
SECTION 26 05 48.00 10
SEISMIC PROTECTION FOR ELECTRICAL EQUIPMENT
10/07
NOTE: This guide specification covers the requirements for seismic protection
of electrical equipment, conduit, and exterior utilities..
Edit this guide specification for project specific requirements by adding, deleting,
or revising text. For bracketed items, choose applicable items(s) or insert
appropriate information.
Remove information and requirements not required in respective project, whether
or not brackets are present.
Comments and suggestions on this guide specification are welcome and should
be directed to the technical proponent of the specification. A listing of technical
proponents, including their organization designation and telephone number, is
on the Internet.
Recommended changes to a UFGS should be submitted as a Criteria Change Request
(CCR).
PART 1 GENERAL
NOTE: The intent of this specification is to provide for adequate resistance
to lateral forces induced by earthquakes for electrical equipment and systems
described herein. The design seismic lateral forces are in addition to the
"normal" gravity forces (weight) acting on the components of a system. This
guide specification will be used in conjunction with Section 13 48 00 SEISMIC
PROTECTION FOR MISCELLANEOUS EQUIPMENT
Equipment in the following seismic design categories do not require protection
from seismic events (refer to UFC 3-310-04 for definition of categories A through
F).
a. Equipment in Seismic Design Categories A and B.
b. Equipment in Seismic Design Category C when the importance factor is equal
to 1.0.
c. Equipment in Seismic Design Categories D, E, and F that are mounted at
1.2 m (4 feet) or less above a floor level and weigh 1780 N (400 lbs) or less
and are not critical to the continued operation of the structure.
d. Equipment in Seismic Design Categories C, D, E, and F weighing 95 N (20
lbs) or less or distribution systems weighing 7 N/m (5 lb/ft) or less.
This section can be used for bracing details of medical equipment by editing
the specification accordingly.
1.1 REFERENCES
NOTE: This paragraph is used to list the publications cited in the text of
the guide specification. The publications are referred to in the text by basic
designation only and listed in this paragraph by organization, designation,
date, and title.
Use the Reference Wizard's Check Reference feature when you add a RID outside
of the Section's Reference Article to automatically place the reference in the
Reference Article. Also use the Reference Wizard's Check Reference feature
to update the issue dates.
References not used in the text will automatically be deleted from this section
of the project specification when you choose to reconcile references in the
publish print process.
The publications listed below form a part of this specification to the extent referenced. The publications are
referred to within the text by the basic designation only.
[AMERICAN INSTITUTE OF STEEL CONSTRUCTION (AISC)AISC 325(2005) Manual of Steel Construction][ASTM INTERNATIONAL (ASTM)ASTM E 580/E 580M(2008a) Application of Ceiling Suspension Systems for Acoustical Tile and Lay-In Panels in Areas Requiring Moderate Seismic Restraint][U.S. DEPARTMENT OF DEFENSE (DOD)UFC 3-310-04(2007) Seismic Design for Buildings][UNDERWRITERS LABORATORIES (UL)UL 1598(2008; Rev thru Nov 2008) Luminaires]1.2 SYSTEM DESCRIPTION
1.2.1 General Requirements
NOTE: Designer should verify that specified details do not interfere with the
performance of the cathodic protection system (when used) or of the vibration
isolation systems.
For systems and equipment in buildings that have a performance objective higher
than life-safety, the designer should show a "GA" classification for the items
under SD-02 Shop Drawings in the SUBMITTALS paragraph. The Engineer of Record
(EOR) should review the details of these essential systems and assess their
impact on the structural supporting system of the essential building.
The requirements for seismic protection measures described in this section shall be applied to the electrical
equipment and systems listed below. Structural requirements shall be in accordance with Section 13 48 00 SEISMIC
PROTECTION FOR MISCELLANEOUS EQUIPMENT.
1.2.2 Electrical Equipment
NOTE: The designer must ensure that the list below includes all electrical
items to be braced. Delete the items which are not part of the project and
add items which are not included in the list.
For equipment and systems in buildings with a performance objective greater
than life-safety, the designer should provide two separate lists of equipment
and systems: 1) Items that are essential to the higher level of post-earthquake
performance, and 2) Items that are not essential but are necessary to provide
a life-safety level of earthquake protection.
Electrical equipment shall include the following items to the extent required on the drawings or in other sections
of these specifications:
Control Panels Air Handling Units
Pumps with Motors Switchgear
Light Fixtures Unit Substations
Motor Control Centers Transformers
Switchboards (Floor Mounted) Storage Racks
[_____] Solar Heating Units
1.2.3 Electrical Systems
NOTE: The designer must list below all electrical systems which are to be installed
or modified.
The following electrical systems shall be installed as required on the drawings and other sections of these specifications
and shall be seismically protected in accordance with this specification: [_____]
1.2.4 Contractor Designed Bracing
NOTE: Retain this paragraph when the Contractor will design the bracing. The
designer will refer and/or modify the listings above or will list below the
equipment and systems to receive seismic bracing. Delete this paragraph when
all bracing details and locations are indicated on the drawings.
The Contractor shall design the bracing in accordance with UFC 3-310-04 and additional data furnished by the
Contracting Officer. Resistance to lateral forces induced by earthquakes shall be accomplished without consideration
of friction resulting from gravity loads. UFC 3-310-04 uses parameters for the building, not for the equipment
in the building; therefore, corresponding adjustments to the formulas shall be required. Loadings determined
using UFC 3-310-04 are based on strength design; therefore, AISC 325 shall be used for the design. The bracing
for the following electrical equipment and systems shall be developed by the Contractor: [_____].
1.2.5 Conduits Requiring No Special Seismic Restraints
NOTE: Retain only those items found in the project for this list of conduits
that do not require seismic restraints. For facilities designated as critical,
hazardous, or essential, delete or make exceptions for conduits which will require
seismic restraint.
Seismic restraints may be omitted from electrical conduit less than 64 mm 2-1/2 inches trade size and [_____].
All other interior conduit, shall be seismically protected as specified.
1.3 EQUIPMENT REQUIREMENTS
NOTE: Seismic control does not guarantee that the equipment itself is rugged
enough to survive earthquake shaking. When a piece of equipment is required
to remain operational after an earthquake, the manufacturer should be consulted
regarding the capabilities of the equipment to withstand seismic loading.
1.3.1 Rigidly Mounted Equipment
NOTE: Rigidly mounted equipment is defined as having a period of vibration
of 0.06 seconds or less for the equipment plus its mounting. Equipment with
a fundamental period greater than 0.06 seconds should be assumed to be flexibly
mounted or nonrigid and designed in accordance with the next paragraph below.
List items that may require additional reinforcements (internally) to prevent
permanent deformation, dislocations, separation of components, or other damage,
which would render the equipment inoperative for significant periods of time
following a seismic event and to meet the specified requirements (such as engine-driven
generators, etc., which consist of a number of individual components built into
an assembly by the manufacturers). For emergency generators include auxiliary
items required for the generator to operate, such as battery racks and day tanks.
The following specific items of equipment: [_____] to be furnished under this contract shall be constructed
and assembled to withstand the seismic forces specified in UFC 3-310-04. Each item of rigid electrical equipment
shall be entirely located and rigidly attached on one side only of a building expansion joint. Piping, electrical
conduit, etc., which cross the expansion joint shall be provided with flexible joints that are capable of accommodating
displacements equal to the full width of the joint in both orthogonal directions.
Engine-Generators
Substations
Transformers
Switch Boards and Switch Gears
Motor Control Centers
Free Standing Electric Motors
[_____]
1.3.2 Nonrigid or Flexibly-Mounted Equipment
NOTE: The appropriate lateral force coefficient, based on the guidelines in
Section 13 48 00 SEISMIC PROTECTION FOR MISCELLANEOUS EQUIPMENT for nonrigid
or flexibly-mounted equipment, should be calculated and inserted in the second
bracketed blank space.
The following specific items of equipment to be furnished: [_____] shall be constructed and assembled to resist
a horizontal lateral force of [_____] times the operating weight of the equipment at the vertical center of gravity
of the equipment.
1.4 SUBMITTALS
NOTE: Review submittal description (SD) definitions in Section 01 33 00 SUBMITTAL
PROCEDURES and edit the following list to reflect only the submittals required
for the project. Submittals should be kept to the minimum required for adequate
quality control.
A “G” following a submittal item indicates that the submittal requires Government
approval. Some submittals are already marked with a “G”. Only delete an existing
“G” if the submittal item is not complex and can be reviewed through the Contractor’s
Quality Control system. Only add a “G” if the submittal is sufficiently important
or complex in context of the project.
For submittals requiring Government approval on Army projects, a code of up
to three characters within the submittal tags may be used following the "G"
designation to indicate the approving authority. Codes for Army projects using
the Resident Management System (RMS) are: "AE" for Architect-Engineer; "DO"
for District Office (Engineering Division or other organization in the District
Office); "AO" for Area Office; "RO" for Resident Office; and "PO" for Project
Office. Codes following the "G" typically are not used for Navy, Air Force,
and NASA projects.
Choose the first bracketed item for Navy, Air Force and NASA projects, or choose
the second bracketed item for Army projects.
Government approval is required for submittals with a "G" designation; submittals not having a "G" designation
are for [Contractor Quality Control approval.] [information only. When used, a designation following the "G"
designation identifies the office that will review the submittal for the Government.] Submit the following in
accordance with Section 01 33 00 SUBMITTAL PROCEDURES:
SD-02 Shop Drawings
Lighting Fixtures in Buildings
Equipment Requirements
Detail drawings along with catalog cuts, templates, and erection and installation details,
as appropriate, for the items listed. Submittals shall be complete in detail; shall indicate
thickness, type, grade, class of metal, and dimensions; and shall show construction details,
reinforcement, anchorage, and installation with relation to the building construction.
SD-03 Product Data
Lighting Fixtures in Buildings[; G][; G, [_____]]
Equipment Requirements[; G][; G, [_____]]
Copies of the design calculations with the detail drawings. Calculations shall be stamped
by a registered engineer and shall verify the capability of structural members to which bracing
is attached for carrying the load from the brace.
Contractor Designed Bracing[; G][; G, [_____]]
Copies of the Design Calculations with the Drawings. Calculations shall be approved, certified,
stamped and signed by a Registered Professional Engineer. Calculations shall verify the capability
of structural members to which bracing is attached for carrying the load from the brace.
PART 2 PRODUCTS
NOTE: Appropriate materials for structural supports must be used in corrosive
environments. Dissimilar metals must be isolated.
2.1 LIGHTING FIXTURE SUPPORTS
Lighting fixtures and supports shall conform to UL 1598.
2.2 SWAY BRACING MATERIALS
Sway bracing materials (e.g. rods, plates, rope, angles, etc.) shall be as specified in Section 13 48 00 SEISMIC
PROTECTION FOR MISCELLANEOUS EQUIPMENT.
PART 3 EXECUTION
3.1 SWAY BRACES FOR CONDUIT
Conduit shall be braced as for an equivalent weight pipe in accordance with Section 13 48 00.00 10 SEISMIC PROTECTION
FOR MECHANICAL EQUIPMENT.
3.2 LIGHTING FIXTURES IN BUILDINGS
Lighting fixtures and supports shall conform to the following:
3.2.1 Pendant Fixtures
Pendant fixtures shall conform to the requirements of UFC 3-310-04.
3.2.2 Ceiling Attached Fixtures
3.2.2.1 Recessed Fluorescent Fixtures
Recessed fluorescent individual or continuous-row mounted fixtures shall be supported by a seismic-resistant
suspended ceiling support system built in accordance with [ASTM E 580/E 580M][Section 09 51 00 ACOUSTICAL CEILINGS].
Seismic protection for the fixtures shall conform to the requirements of UFC 3-310-04. Recessed lighting fixtures
not over 25 kg 56 pounds in weight may be supported by and attached directly to the ceiling system runners using
screws or bolts, number and size as required by the seismic design. Fixture accessories, including louvers,
diffusers, and lenses shall have lock or screw attachments.
3.2.2.2 Surface-Mounted Fluorescent Fixtures
Surface-mounted fluorescent individual or continuous-row fixtures shall be attached to a seismic-resistant ceiling
support system built in accordance with [ASTM E 580/E 580M][Section 09 51 00 ACOUSTICAL CEILINGS]. Seismic protection
for the fixtures shall conform to the requirements of UFC 3-310-04.
3.2.3 Assembly Mounted on Outlet Box
A supporting assembly, that is intended to be mounted on an outlet box, shall be designed to accommodate mounting
features on [100] [75] mm [4] [3] inch boxes, plaster rings, and fixture studs.
3.2.4 Wall-Mounted Emergency Light Unit
Attachments for wall-mounted emergency light units shall be designed and secured for the worst expected seismic
disturbance at the site.
3.2.5 Lateral Force
Structural requirements for light fixture bracing shall be in accordance with Section 13 48 00 SEISMIC PROTECTION
FOR MISCELLANIOUS EQUIPMENT.