USACE / NAVFAC / AFCESA / NASA UFGS-27 21 00.00 40 (November 2008)
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Preparing Activity: NASA (NEW)
UNIFIED FACILITIES GUIDE SPECIFICATIONS
References are in agreement with UMRL dated January 2009
SECTION 27 21 00.00 40
INTERCOMMUNICATION SYSTEM
11/08
NOTE: This guide specification covers the requirements for five different types
of intercommunication systems one of which shall be selected for the project.
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).
NOTE: (For brig facilities, Type 1 shall be selected for the station to station
intercommunications and Type 5 shall be selected for the public address and
monitoring function for the project.) The various types are as follows:
1. Type 1: Direct connected, keyed system: This type of system is applicable
for relatively small systems (maximum quantity of remote stations approximately
30) and generally when only a small number of master stations (usually 1 or
2) are required. However, if there is a requirement for annunciation at more
than one location or a requirement for multiple conversation paths the use of
this system with more than 1 or 2 master stations or with many more than 30
remote stations may be justified or required.
2. Type 2: Single conversation path, central control system: This type of
system is applicable to relatively large systems (more than approximately 30
stations) where only one conversation path is required and usually only one
master station. This type of system is applicable to BEQs.
3. Type 3: Multiple conversation paths, central control system: This type
of system is applicable to various size systems where a large portion of the
total quantity of stations are master stations. A limited quantity of conversation
paths may be specified as required.
4. Type 4: Paging system: This type of system provides one-way communications,
using conventional public address system components. By proper inclusion of
radio components it applies to radio paging.
5. Type 5: Public address and monitoring system (for brigs): This type of
system provides two-way paging and monitoring communications, using conventional
public address system components.
NOTE: Require shop drawings to supplement or clarify contract drawings. Contract
drawings should clearly indicate approximate locations of all stations, conduit,
and junction boxes. State precisely in the project specifications what is to
be shown in detail drawings. If contract drawings do not show the locations
of master stations, remote stations, junction boxes, and other system components,
then the number and type of stations, junction boxes, and the distance between
them shall be included as a part of the contract specifications.
The guide specification covers intercommunication system and lists desirable
features of electronic systems; however, not all manufacturers produce products
with all the listed features. Manufacturers catalogs should be consulted for
the features required. Where intercommunication systems are to be used with
other communication devices, consideration must be given to the electromagnetic
capability of the intercommunication system. This intercommunication system
guide specification does not include all features and design parameters which
are available. However, specifying equipment configuration or design parameters
which are unnecessarily restrictive to competition should be avoided.
PART 1 GENERAL
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.
[ACOUSTICAL SOCIETY OF AMERICA (ASA)ASA S3.2(1989; R 1999) Method for Measuring the Intelligibility of Speech Over Communication Systems (ASA 85)][INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS (IEEE)IEEE C62.41.1(2002) IEEE Guide on the Surges Environment in Low-Voltage (1000 V and Less) AC Power CircuitsIEEE C62.41.2(2002) IEEE Recommended Practice on Characterization of Surges in Low-Voltage (1000 V and Less) AC Power Circuits][NATIONAL FIRE PROTECTION ASSOCIATION (NFPA)NFPA 70(2007; AMD 1 2008) National Electrical Code - 2008 Edition][UNDERWRITERS LABORATORIES (UL)UL 50(2007) Standard for Enclosures for Electrical EquipmentUL 6(2007) Standard for Electrical Rigid Metal Conduit-SteelUL 797(2007) Standard for Electrical Metallic Tubing -- Steel]1.2 RELATED REQUIREMENTS
Section 26 00 00.00 20 BASIC ELECTRICAL MATERIALS AND METHODS, applies to this section, with the additions and
modifications specified herein.
1.3 SYSTEM DESCRIPTION
NOTE: Delete paragraph and subparagraph if Type 4 or 5 is specified.
1.3.1 Performance Requirement for Type [1] [2] [3] System
Solid state, modular in design, and shall be of the [wired] [and] [wireless] type with [all master stations]
[a single master with remote stations] [master and remote stations intermixed]. [Station shall have capacity
for later expansion to [[_____] master] [and] [[____] remote] stations [with [_____] handset] without sacrificing
any equipment or feature performance]. [When both wired and wireless circuitry is used, do not reduce such interface
function or quality].
1.3.1.1 Sound Reproduction
The intercommunication system shall reproduce at all receiving stations a 30 dB dynamic range of a 40 dB minimum
input signal referenced to sound pressure level (SPL) over the frequency range of [300] [_____] to [3300] [_____]
Hz. Unless otherwise specified, SPL shall be 20 micro Pascal (0.00002 Newtons per square meter). The root-mean
square (rms) extraneous noise (e.g. hum) level introduced by the intercommunication system shall be at least
[30] [_____] dB below the nominal signal level. Distortion, including envelope delay, intermodulation, cross
talk, and other nonlinear source, shall not exceed 5 percent.
1.3.1.2 System Performance
Provide system with normally acceptable speech intelligibility, defined as a score of at least 75 percent obtained
utilizing the phonetically balanced monosyllabic work intelligibility test in accordance with ASA S3.2.
1.3.1.3 System Operation and Service Features
a. Provide the system with a power switch and an associated pilot light for ON and OFF operations.
Include a volume switch at each station to regulate listening volume. Unless otherwise specified,
operate the system on 120 Vac, single phase, 60 Hz source.
b. All master stations shall have a "call-in" switch to provide an audible and visual indication
of incoming calls from remote station. Individual visual indication shall identify calling
station and status, and remain actuated until a call is answered by a master station.
c. In addition to the manufacturer's standard identification plates, provide engraved laminated
phenolic identification plates for each component connection and terminal identification labels,
and shall be 3-layer black on white on black, engraved to show white letters on black background.
Warning or caution labels shall be 3-layers red on white on red, engrave to show white letters
on red background. Clearly mark control switches and knobs with their function and status.
Locate identification strips for station selector switches to clearly identify remote and master
stations and protect by transparent plastic inserts. Lettering shall be a minimum of 6.35 mm
1/4 inch high, normal block style.
d. At speaker/handset stations, lifting the handset shall automatically cut out the loudspeaker
in the station and all conversation shall be carried through handset.
NOTE: Regarding the text below, where noise does not exceed 55 dB, specify
hands-free operation from distances up to 6100 mm 20 feet. In areas where the
noise occasionally exceeds 55 dB, a talk-listen switch which overrides the hands-free
operation should be specified. Where a high noise environment exists, delete
hands-free operation and specify only a talk listen switch.
e. Provide a privacy switch at each remote station. In the ON position, the switch shall prevent
any transmission of sound from the remote station. When in the OFF position, without further
switch manipulation, the station shall respond to incoming calls upon voice activation from
anywhere within 6100 mm 20 footradius of station.
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.][for 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
Intercommunication system
Submit for overall system and for each major component. Illustrate how each item of equipment
will function in the system and include an overall system schematic indicating relationship
of intercommunication units on one diagram identifying type, size, and number of wiring, conduits
and each major component.
SD-03 Product Data
Materials and equipment for Type [1] [2] [3] system
[Paging system equipment]
[Public address and monitoring system equipment]
Cables and raceways
Surge protection
SD-10 Operation and Maintenance Data
Intercommunication system, Data Package 5
Submit in accordance with Section 01 78 23 OPERATION AND MAINTENANCE DATA.
PART 2 PRODUCTS
2.1 EQUIPMENT AND COMPONENTS
Equipment and components shall conform to applicable requirements of NFPA 70. Units of the same type of the
equipment shall be product of single manufacturer. Units to be mounted outside or subject to inclement conditions
shall be weatherproof or to be mounted in weatherproof enclosures.
[2.1.1 Type 1 System: Direct Connected Keyed Intercommunication System
NOTE: Select the appropriate paragraph and its following subparagraphs for
the features desired. Delete all paragraphs describing unwanted features.
Provide master stations and remote stations in the quantities indicated. Each master station shall selectively
communicate with any other master station and any remote station by actuating an appropriate selector switch.
[Each master station shall be capable of initiating a message to all other master stations and all remote stations
simultaneously or in groups of not less than ten stations per group.]
2.1.1.1 Master Station
[Desk] [surface wall] [recessed wall] [rack]-mounted master stations shall as a minimum conform to the following
specifications:
a. Capacity: Accommodate [_____] stations
b. Speaker sensitivity: Minimum 40 dB
2.1.1.2 Intercommunication Amplifier
Intercommunication amplifier shall as a minimum conform to the following specifications:
a. Output power: [2] [_____] watts rms or greater
b. Total harmonic distortion: Less than 5 percent at rated power with a load equivalent to
one station connected to output terminals
c. Signal-to-noise ratio: 60 dB or greater at rated output
d. Frequency response ratio: Plus or minus 2 dB from 200 Hz to 10,000 Hz
2.1.1.3 Remote Station
[Desk] [surface wall] [recessed wall] [rack]-mounted remote station shall have [stainless] [anodized aluminum]
faceplate with temper proof mounting screws and [galvanized steel] [aluminum] backbox [with "station call-in"
capabilities]. Remote station shall provide a speaker with a minimum sensitivity of 40 dB for speakers less
than 200 mm 8 inches in diameter and 45 dB for speakers 200 mm 8 inches or greater. Remote station shall have
a call announcement monitor lamp [and recurring momentary tone].
2.1.1.4 All-Call Amplifier
NOTE: Include only when it is determined that an all-call feature is an operational
requirement.
All-call amplifier shall as a minimum conform to the following specifications:
a. Output power: Minimum of [0.5] [_____] watts for each station
b. Total harmonic distortion: Less than 5 percent at rated power with a load equivalent to
the quantity of stations connected to it in all-call mode of operation
c. Signal-to-noise ratio: 60 dB or greater at rated output
d. Frequency response ratio: Plus or minus 2 dB from 200 Hz to 10,000 Hz
][2.1.2 Type 2 System
NOTE: Select the appropriate paragraph and its following subparagraphs for
the features desired. Delete paragraphs describing the features not required.
Provide single conversation path, central control intercommunication system with a master station, automatic
switching equipment, remote stations and [an annunciator panel] and all amplifiers. Master station shall selectively
communicate with any remote station by actuating the [two] [three] digit number assigned to that remote station.
[Design master station to communicate with all remote stations simultaneously or in groups of not less than 10
stations by actuating an assigned "all-call" number.] Only the selected remote station shall be able to listen
or talk to the master station. A nonselected remote station shall not be able to hear or interfere with any
portion of conversation between master station and selected remote station. Hanging up master station handset
shall reset system for next call. Quantity and location of remote stations shall be as indicated.
2.1.2.1 Master Station
Provide [desk-top] [rack]-mounted type master station equipped with a handset with a switch for private conversations
[with permanently coiled cord, approximately 1525 mm 5 feet long extended]. Master station shall have molded
shock-resistant plastic handset and housing. Mount housing on a steel base plate with a station selector with
ten-digit, silent operating touch key mechanism.
2.1.2.2 Remote Station
Provide [desk-top] [surface wall] [recessed wall] [rack]-mounted remote stations with [stainless steel] [anodized
aluminum] face plates with temperproof mounting screws and [galvanized steel] [aluminum] backbox. [Provide a
"call-in" switch mounted on a faceplate to provide selective call-in to master station as an integral part of
the remote station.] Remote stations shall provide a speaker with a minimum sensitivity of 40 dB for speakers
less than 200 mm 8 inches in diameter and at least 45 dB for speakers 200 mm 8 inches or greater. Remote stations
shall have a call announcement monitor lamp [and recurring momentary tone].
2.1.2.3 Intercommunication Amplifier
Intercommunication amplifier shall as a minimum conform to the following specifications:
a. Output power: [2] [_____] watts rms or greater
b. Total harmonic distortion: Less than 5 percent at rated output power with a load equivalent
to one station connected to output terminals
c. Signal-to-noise ratio: 60 dB or greater at rated output
d. Frequency response ratio: Plus or minus 2 dB from 200 Hz to 10,000 Hz
2.1.2.4 All-Call Amplifier
All-call amplifier shall as a minimum conform to the following specifications:
a. Output power: Minimum of [0.5] [_____] watt rms for each station
b. Total harmonic distortion: Less than 5 percent at rated output power with a load equivalent
to the quantity of stations connected to it in all-call mode of operation
c. Signal-to-noise ratio: 60 dB or greater at rated output
d. Frequency response ratio: Plus or minus 2 dB from 200 Hz to 10,000 Hz
2.1.2.5 Horn-Type Loudspeakers
NOTE: Use 57 decibels for axial sensitivity of bi-directional and compound
diffraction horns.
Provide horn-type loudspeakers with line transformers and mounting brackets and as a minimum conform to the following
specifications:
a. Frequency response: Plus or minus 3 dB from 250 Hz to 10,000 Hz
b. Power rating: [5] [_____] watts
c. Horizontal dispersion angle: [one] [1.57] [2] [_____] rad [57] [90] [115] [_____] degrees
d. Vertical dispersion angle: [one] [1.57] [2] [_____] rad [57] [90] [115] [_____] degrees
e. Axial sensitivity: Minimum of [57] [60] [_____] dB
f. Line transformers power rating: At least 4 watts
][2.1.3 Type 3 System
NOTE: Select the appropriate paragraph and its following subparagraphs for
the features desired. Delete all paragraphs describing features not required.
Provide multiple conversation paths, central control intercommunication system capable of communicating with
the other master stations and remote stations selectively or in any combination thereof. [Each master station
shall selectively communicate with any other master station or remote station by actuating number assigned to
initiate a message to all other master stations and all remote stations simultaneously or in groups of not less
than 10 stations.]
2.1.3.1 Master Stations
Provide [desk-top] [surface wall] [recessed wall] [rack]-mounted master stations with ten digit touch key station
selector mechanism. Master station shall have a speaker-microphone with at least 40 dB sensitivity. Master
station shall also have a push-button type reset button to cancel calls and reset system for next call.
2.1.3.2 Remote Station
Provide [desk-top] [surface wall] [recessed wall] [rack]-mounted remote stations with [stainless steel] [anodized
aluminum] face plates with temperproof mounting screws and [galvanized steel] [aluminum] backbox. [Provide a
"call-in" switch mounted on a faceplate to provide selective call-in master station as an integral part of the
remote station.] Remote station shall provide speakers with a minimum sensitivity of 40 dB for speakers less
than 200 mm 8 inches in diameter and at least 45 dB for speaker 200 mm 8 inches or greater.
2.1.3.3 Intercommunication Amplifier
Intercommunication amplifier shall as a minimum conform to the following specifications:
a. Output power: [2] [_____] watts rms or greater
b. Total harmonic distortion: Less than 5 percent at rated output power with a load equivalent
to a load equivalent to one station connected output terminals
c. Signal-to-noise ratio: 60 dB or greater at rated output
d. Frequency response ratio: Plus or minus 2 dB from 200 Hz to 10,000 Hz
2.1.3.4 All-Call Amplifier
All-call amplifier shall as a minimum conform to the following specifications:
a. Output power: Minimum of [0.5] [_____] watt rms for each station
b. Total harmonic distortion: Less than 5 percent at rated power with a load equivalent to
[_____] stations connected to output terminal all-call mode of operation
c. Signal-to-noise ratio: 60 dB or greater at rated output
d. Frequency response ratio: Plus or minus 2 dB from 50 Hz to 10,000 Hz
2.1.3.5 Horn-Type Loudspeakers
NOTE: Use 57 decibels for axial sensitivity of bi-directional and compound
diffraction horns.
Provide horn-type loudspeakers with line transformers and mounting brackets and as a minimum conform to the following
specifications:
a. Frequency response ratio: Plus or minus 3 dB from 250 Hz to 10,000 Hz
b. Power rating: [25] [_____] watts
c. Horizontal dispersion angle: [one] [1.57] [2] [_____] rad [57] [90] [115] [_____] degrees
d. Vertical dispersion angle: [one] [1.57] [2] [_____] rad [57] [90] [115] [_____] degrees
e. Axial sensitivity: Minimum of [57] [60] [_____] dB
f. Line transformers power rating: At least 4 watts
][2.1.4 Type 4 System: Paging System
NOTE: Select the appropriate paragraph and its following subparagraphs for
the features desired. Delete paragraphs describing the features not required.
System capacity should include future expansion requirements.
Provide paging system including amplifier, preamplifier, control panel, speakers, microphone, and interconnecting
cables. Operate all speakers from a [70] [25] volt distribution system. System shall be solid state, and integrated
design of a single supplier.
2.1.4.1 Preamplifier/Mixer
Provide preamplifier/mixer either separately or as an integral part of power amplifier. If separate, it shall
be completely self-contained, requiring only a 120 Vac power source. Provide controls which are front panel
mounted, and include ON/OFF switch with power on visual indicator. Preamplifier shall employee only solid state
devices and shall be as a minimum conform to the following specifications:
a. Inputs: Microphone: Low impedance, 150 ohms nominal
Auxiliary: High impedance, 500,000 ohms or greater
b. Signal-to-noise ratio: 60 dB or greater at rated output
c. Frequency response ratio: Plus or minus 2 dB from 20 Hz to 20,000 Hz
d. Total harmonic distortion: Less than 3 percent at rated output power
e. Output: Shall be sufficient to drive power amplifier to rated output
2.1.4.2 Power Amplifier
Power amplifier shall employ only solid state devices and as a minimum conform to the following specifications:
NOTE: To specify proper power rating of amplifier, allow 1 watt for each cone
type speaker and 1.5 watts for each horn type. Special circumstances may dictate
greater power requirements.
Provide controls which are front panel mounted, and include ON/OFF switch
with power-on visual indicator. Power amplifier shall employ only solid state devices. Performance characteristics:
a. Power output: [_____] watts or greater
b. Signal-to-noise ratio: 60 dB or greater at rated output
c. Frequency response ratio: Plus or minus 3 dB from 100 Hz 10,000 Hz
d. Total harmonic distortion: Less than 3 percent at rated output
e. Power requirements: 120 Vac, 60 Hz
2.1.4.3 Cone Speaker
Provide [ceiling] [wall] [pendant]-mounted cone type speakers. Include rust-proof back boxes of acoustically
damped construction, minimum 20 gage steel or aluminum; provide for relief of back pressure. Include suitable
recessed mounted speaker grille, made of 20 gage minimum steel or aluminum. Speaker assembly shall as a minimum
conform to the following specifications:
a. Sensitivity (sound pressure level): Minimum of 92 dB, measured at 1 watt input, 1200 mm
4 feet on axis
b. Frequency response ratio: Plus or minus 3 dB from 80 Hz to 12,000 Hz
c. Dispersion angle: 1.57 rad 90 degrees
d. Transformer with 4 level taps: [1/4] [1/2] [1] [2] [5] [10] [15] [_____] watts
e. Voice coils: 25 mm one inch
2.1.4.4 Horn-Type Loudspeakers
NOTE: Ensure mounting height is indicated on the drawings.
Provide horn-type loudspeakers with line transformers, mounting brackets and all hardware, mount at heights indicated
on drawings, and as a minimum conform to the following specifications:
a. Power rating: [15] [20] watts
b. Frequency response ratio: Plus or minus 3 dB from 250 Hz to 10,000 Hz
c. Horizontal dispersion angle: [one] [1.57] [2] [_____] rad [57] [90] [115] [_____] degrees
d. Vertical dispersion angle: [one] [1.57] [2] [_____] rad [57] [90] [115] [_____] degrees
e. Sensitivity (sound pressure level): Minimum of 97 dB measured at 1 watt input, 1200 mm
4 feet on axis
f. Power taps: [1/2] [1] [2] [4] [5] [10] [15] [20] [25] [_____] watts
2.1.4.5 Microphone
Provide dynamic omni-directional microphones, [wall-mounted] [desk-mounted with desk stand and touch-to-talk
bar]. Include zone selector switches [with indicating lights]. Microphones shall as a minimum conform to the
following specifications:
a. Frequency response ratio: Plus or minus 3 dB from 60 Hz to 10,000 Hz
b. Impedance: Low impedance, 150 ohms nominal
c. Output level: 58 dB minimum
][2.1.5 Type 5 System: Public Address and Monitoring System for Brigs
NOTE: Choose the appropriate paragraph and its following subparagraphs for
the features desired. Delete paragraphs describing features not required.
System capacity should include future expansion requirements.
NOTE: Use these paragraph and its subparagraphs for brig facilities only.
Not all manufacturers produce all the listed features. Therefore, manufacturers
catalogs may be consulted as to the features required. Avoid specifying equipment
configuration or design parameters which are unnecessarily restrictive to competition.
Provide amplifier, preamplifier, control panel, speakers, microphone, and interconnecting cables. Operate speakers
from a [70] [25] volt distribution system.
2.1.5.1 Detection of Central Public Address System Trouble
Central public address system shall be continuously supervised for detection of system trouble such as opens,
shorts, grounds, mechanical damage, power loss in all amplifiers (signal generators), external wiring and speakers
including voice controls and cones. Rack-mount system supervisory equipment.
2.1.5.2 Speakers
Speaker shall be two-way speaker/microphone type for use as audio monitoring devices as well as public address
speakers. Each speaker installation shall be complete including, where applicable, drivers, matching transformers,
mounting brackets, acoustically treated back boxes, and baffles selected with audio characteristics and physical
construction that are compatible with the total system.
a. Speaker installed in inmate housing groups shall be [dual] reentrant horn suitable for voice
announcements and area monitoring in areas of high ambient noise level. Speakers shall be suitable
for indoor [and outdoor] use and shall conform to not less than the following:
Continuous [15] [30] [30] [30]
Power Rating
(Watts)
Frequency [275-14,000] [225-14,000] [250-14,000] [225-14,000]
Response (Hz)
Dispersion [1.74 rad] [1.74 rad] [2.09 by 1.04 rad] [1.74 rad] Dispersion [100 degrees] [100 degrees]
[120 by 60 degrees] [100 degrees]
Sound Pressure at
1200 mm 4 Feet
on Axis with
Rated Inputs
(Decibels): [121] [125] [123] [121]
Impendance
Range (Ohms)
[45 to 5000] [45 to 2400] [45 to 2500] [45 to 2500]
Mounting: [Universal [Universal [Universal [Universal
3 way ad- 3 way ad- 3 way ad- 3 way ad-
justable] justable] justable] justable]
Area Use: [Indoor/ [Indoor/ [Indoor/ [Indoor/
Outdoor] Outdoor] Outdoor] Outdoor]
b. Speakers installed for large area public address systems shall be loudspeaker reflex trumpet
of weatherproof construction conforming to not less than the following specifications:
(1) Continuous power rating with driver: [_____] watts
(2) Frequency response: [_____] Hz
(3) Dispersion angle: [85 degrees] [120 by 60 degrees] [1.48 rad] [2.09 by 1.04 rad]
(4) Sound pressure level input: [_____] dB at 1200 mm 4 feet on Axis with Rated Input
(5) Impedance range: [_____] Ohms [Manufacturer's standard for 40 watt audio power on 70 volt
system]
(6) Mounting: Universal three-way adjustable
(7) Area use: Indoor/Outdoor
c. Flush mounted speakers shall be mounted in acoustically treated backbox and provided with
high impact square plastic baffle attached to backbox with spanner head bolts. Speakers shall
conform to not less than the following:
(1) Continuous power rating: [10] [15]
(Watts)
(2) Frequency response: [80 to 12,000] [30 to 20,000]
(Hz)
(3) Speaker diameter: [Nominal 200] [Nominal 200](3) Speaker diameter
[Nominal 8] [Nominal 8]
(mm)(Inches)
2.1.5.3 Security Baffle
Provide [flush] [surface]-mounted speakers in security type enclosures. Baffle shall consist of high tensile
strength 275.6 MPa 40,000 psi case aluminum alloy outer ring and stainless steel woven wire mesh speaker screen
spun over and attached to subplate mounting assembly.
a. Securely attach baffle to speaker enclosure with tamperproof flush screws. Speaker enclosure
shall be acoustically treated, of the correct depth for the speaker assembly to be installed
and suitable for flush mounting in masonry [wall] [ceiling].
b. Securely mount baffle from the inside to a surface mounted 11 gage tempered, aluminum plate,
housing, rolled into cylindrical shape heliarc welded. Installation shall include an 11 gage
aluminum ring for support of speaker/baffle. Attach all components with tamperproof, flush
screws. Attach housing to mounting surface with lead shields on masonry and machine bolts on
structural steel.
NOTE: Regarding text below, coordinate speaker mounting detail on the drawings.
c. Install monitor speakers with each subsystem to have monitoring feature. Rate speaker at
not less than 5 watts output continuous with frequency response from 100 Hz to 10,000 Hz. Nominal
diameter shall not be less than 150 mm 6 inches. Where speakers are indicated to be independently
mounted, provide speakers with high impact plastic or stainless steel baffle and flush mounted
in acoustically treated back box. Provide speakers where monitor speaker is indicated to be
rack mounted with other equipment.
2.1.5.4 Amplifiers
Power amplifiers shall be [rack] [shelf]-mounted. [Where mounted in same location as other audio equipment,
mount all equipment in common rack.] Power amplifiers shall contain circuit breaker for overload protection,
high temperature automatic reset protection and electronic output protection. Power amplifiers shall as a minimum
conform to the following:
Audio Power Output: [60] [125] [250] [400]
(Watts)
Distortion (percent): [5] [5] [2] [5]
Frequency Response: [20 to 20,000] [20 to 29,000] [30 to 20,000] [20 to___]
(Hz)
Noise Level (below
raised output in dB): [75] [75] [80] [75]
Load Impedance
70 volts (ohms): [100] [50] [25] [15]
Load Impedance
25 volts (ohms): [12.5] [6.25] [3.25] [1.88]
Power Required at
Rated Output(watts): [125] [240] [600] [840]
Rack Mounting: [140] [220] [310] [355] Rack Mounting: [5 1/2]
[8 3/4] [12 1/4] [14]
mm Inches
a. Pre-amplifier shall be solid state for use with the power amplifiers specified and shall
be [rack] [shelf]-mounted. Provide pre-amplifier with power on-off switch, monitor volume control,
program volume control, and call selector switch and VU meter. Make connections between the
station selector switch panel for either "program" or "monitoring" of selected stations. Pre-amplifier
shall as minimum conform to the following:
(1) Power output: Compatible with power amplifiers
(2) Frequency response: Plus and minus [_____] dB from 20 Hz to 20,000 Hz
(3) Noise level: -50 dB
(4) Distortion: Less than 5 percent
b. Booster amplifiers shall be solid state type incorporated into total system to amplify audio
signal from central power amplifiers. Booster amplifier shall be [rack] [shelf]-mounted and
shall as minimum conform to not less than the following specifications:
(1) Power output: 15 watts
(2) Peak power output: 25 watts
(3) Frequency response: Plus and minus [_____] dB from 20 Hz to 12,000 Hz
(4) Noise level: -50 dB
(5) Distortion: Less than 5 percent
2.1.5.5 Microphone
Microphone shall be dynamic, omni-directional type with desk stand and touch-to-talk bar. Frequency range shall
be from 60 to 10,000 Hz. Construction shall be of die cast zinc alloy. Finish shall be satin chrome. Connect
microphone with portable cord and microphone plug inserted into flush mounted microphone jack.
a. Provide desk mounted telephone type handset [in the Commanding Officer's Office] [at the
location indicated] for use with public address system. Construct handset of high impact plastic
with heavy-duty coil cord. Handset shall contain a press-to-talk switch, which, when pressed,
shall automatically connect handset to "all call" mode of system.
2.1.5.6 Station Selector Switch Panel
Incorporate station selector switch panels into each public address and monitoring subsystem and into the central
public address system. Selector switch panels shall be rack mounted type containing not less than twenty-five
switch positions. Switch positions not required may be blanked, or if switches are provided, clearly identify
unused switches.
a. Subsystem selector switch panels shall contain [four] [_____] station control switches with
double pole, three position for "MONITOR", "OFF", and "INTERCOM". Provide one additional switch
for "ALL CALL" of subsystems stations.
b. Central system selector switch panel shall contain [_____] station control switches with
double pole, two position lever type switch with "OFF" and "PUBLIC ADDRESS" positions. Provide
one additional switch for "ALL CALL" to all subsystems.
c. Provide switches with self-wiping, precious metal contacts, and means of switch identification.
2.1.5.7 Supervision Module
Provide supervision module for the central public address system with audible and visual alarms to signify that
a component of the supervised systems is malfunctioning. Panel shall contain a silencing switch to deenergize
audible signal and pilot lamps to remain activated until system fault has been corrected. Panel shall be [rack-mounted
with central amplification equipment] [mounted with preamplifier at central operation location].
]2.2 CABLES AND RACEWAYS
Cable and raceways shall conform to UL 6 and UL 797. Cabinets and boxes shall conform to UL 50. Cables for use
in air plenums shall be UL classified low smoke and low flame in accordance with NFPA 70.
2.2.1 Speaker Cable
Basic cables shall be single twisted pair shielded cables, 22 gage, stranded tinned copper with vinyl insulation
aluminum polyester shield, stranded tinned copper wire with overall vinyl jacket. Multi-conductor shielded pair
cables conforming to basic speaker cable specifications are acceptable.
2.2.2 Microphone Cable
Cable shall be single conductor shielded cable stranded copper No. [25] [_____] AWG rubber insulated, tinned
copper shield and rubber overall jacket.
2.3 TERMINALS
Terminals shall be [solderless, tool-crimped pressure] [or] [_____] type.
2.4 SURGE PROTECTION
Major components of the system such as master stations, amplifiers, and remote stations, shall have a device,
either internal or external, which shall provide protection against voltage spikes and current surges conforming
to IEEE C62.41.1 and IEEE C62.41.2.
2.5 SPEAKER ENCLOSURES
Speaker enclosures shall be compatible with the speakers specified and shall comply with UL 50.
PART 3 EXECUTION
3.1 INSTALLATION
3.1.1 General
Install all system components and appurtenances in accordance with the manufacturer's instructions and as specified
herein.
3.1.2 Wiring
Install wiring in rigid metal conduit, intermediate metal conduit, cable tray, or electric metallic tubing as
specified in Section 26 20 00 INTERIOR DISTRIBUTION SYSTEM. Wiring for signal circuits shall terminate on identified
terminal blocks in cabinets and master station enclosures. Terminate audio circuits on identified terminal blocks
in cabinets and master stations. Ground cable shield at all points of termination.
3.1.2.1 Signal Wiring and Control Wiring
Install signal and control circuits in accordance with NFPA 70. Provide type of signal and control wires and
number of conductors as recommended by the intercommunication system manufacturer, and as necessary to provide
a complete and operable system.
3.1.3 Grounding
NFPA 70. Ground and distribution ground buses shall be solid copper wire with insulating covering.
3.2 FIELD QUALITY CONTROL
3.2.1 Acceptance Tests
After installation has been completed, Contractor shall conduct an acceptance test in the presence of the Contracting
Officer or its representative, to demonstrate that the equipment operates in accordance with specification requirements.
Contractor shall notify the Contracting Officer [2 weeks] [_____] prior to performance of tests. The acceptance
tests shall include originating and accepting messages at specified stations, at proper volume levels, without
cross-talk or noise from other links or non-designated units. Test shall utilize the phonetically balanced monosyllabic
work intelligibility test in accordance with ASA S3.2. In order to be acceptable a score of at least 75 percent
must be obtained for each system test.
3.2.2 Retesting
Rectify deficiencies indicated by tests and completely retest work affected by such deficiencies at Contractor's
expense.
3.3 INSPECTION
Make observations to verify that units and controls are properly labeled, and interconnecting wires and terminals
identified.