Federal Signal Corporation Atkinson Dynamics AD-26 Manual

2561494
Rev. H2 620
Printed in U.S.A.
© 2020 Federal Signal Corporation
AD-26, AD-27, AD-56, and AD-57
Atkinson Dynamics Wall Mount Intercoms
Installation and Maintenance Manual
2645 Federal Signal Drive
University Park, IL 60484-3167
www.fedsig.com

2
INSTALLATION AND SERVICE INSTRUCTIONS FOR ATKINSON DYNAMICS
HEAVY-DUTY INTERCOMS
SAFETY MESSAGE TO INSTALLERS, USERS AND MAINTENANCE PERSONNEL
It is important to follow all instructions shipped with this product. This device is to be
installed by a trained electrician who is thoroughly familiar with the National Electrical
Code and will follow NEC Guidelines as well as local codes. Marine installations shall be in
accordance with Title 46, CFR, Parts 110‑113.
The selection of the mounting location for the device, its controls and the routing on the
wiring is to be accomplished under the direction of the facilities engineer and the safety
engineer. In addition, listed below are some other important safety instructions and
precautions you should follow:
• This is not a listed safety device and is not intended to be used as such.
• Read and understand all instructions before installing or operating this equipment.
• Disconnect power before connecting or doing any maintenance on this intercom.
• All effective warning speakers produce loud sounds which may cause in certain
situations, permanent hearing loss. You should take appropriate precautions such as
wearing hearing protection.
• After testing is complete, provide a copy of this instruction sheet to all operating
personnel.
• Establish a procedure to routinely check the intercom installation for integrity and proper
operation. Any maintenance must be performed by a trained electrician in accordance
with NEC guidelines and local codes.
Failure to follow all safety precautions and instructions may result in property damage,
serious injury, or death to you or others.
A. General Features.
The Atkinson Dynamics intercom is a heavy‑duty, 2‑way, communications device
designed for industrial applications. There are four basic models: AD‑26, 12VDC;
AD‑56, 24VDC; AD‑27, 120VAC 50/60 Hz; and AD‑57, 240VAC 50/60 Hz. The AC line
is fused with a 1/2 A, 250 V GMC fuse in the 120/240VAC units. A description of the
available models follows.
Basic Model Specifications
Model AD-26 AD-56 AD-27 AD-57
Supply Voltage 12VDC 24VDC 120VAC,
50/60 Hz
240VAC,
50/60 Hz
Audio Power Output
(Max.) 8.0 W 11.7 W 11.3 W 11.3 W
Power Consumption
(Max.) 20.0 W 39.6 W 28.8 W 30.5 W
Operating Current
(Nominal) 1.47 A 1.65 A 0.240 A 0.127 A
Operating Temperature ‑31 °F to
150 °F
‑31 °F to
150 °F
‑31 °F to
150 °F
‑31 °F to
150 °F
Shipping Weight 10 lb 10 lb 10 lb 11 oz 10 lb 11 oz
Dimensions See Figure 20 on page 26
Ratings UL, cUL, Marine‑Listed, CE (Model AD‑27)
NEMA‑Type 4X (excluding microphone models)
Table 1

3
PRIMARY UNITS:
The “C” models default to Primary, or speaker, mode. In Primary mode, the unit acts as
a speaker and broadcasts audio signals generated elsewhere in the intercom system.
Depressing the Talk switch turns the unit into a microphone and enables the user to
broadcast to all other intercoms in the system. Releasing the switch returns the unit to
Primary mode. Figure 4 on page 10 illustrates a Primary/Secondary intercom system.
SECONDARY UNITS:
The “D” models default to Secondary, or microphone, mode. In Secondary mode, the
unit is designed to serve as a hands‑free microphone with transmission to all Primary
units in the intercom system. The Secondary unit will act as a speaker and broadcast
audio transmissions only when the Talk switch of any Primary unit in the intercom
system is depressed. Figure 4 on page 10 illustrates a Primary/ Secondary intercom
system.
CALL BUTTON:
The “A” models are equipped with a Call switch. Depressing the call switch transmits an
890 Hz tone to all units in the intercom system.
The call signal is louder than normal voice messages being carried on the line.
Do not depress the call switch while carrying on a conversation with someone on the
system. This will subject the listener to very loud sound levels.
The volume of the call signal is affected by the volume control on the receiving unit, so if
volume is turned all the way down at a receiving station, the call signal will not be heard.
MICROPHONE:
The “‑7” Hand‑Held Noise Cancelling Microphones are recommended for use in
environments with high levels of ambient noise. Keying the microphone overrides the
default mode of the intercom and enables audio transmission to all Primary units in
the intercom system. Figure 2 on page 8 illustrates a common intercom system where
hand‑held microphones are used.
Additional Model Information
Letter Group Function/Feature
“A” Call button
“C” Primary mode
“D” Secondary mode
Number Group
“‑1” Remote power
“‑2” Provisions for external talk/listen switch (foot pedal ready)
“‑3” External call contacts for auxiliary signal
“‑4” Extreme temperature use (‑50 °F to 150 °F)
“‑6” Designed for use in a zoned system
“‑7” Provisions for hand‑held noise canceling microphone
“‑8” Additional pre‑amp for use with remote Secondary speaker
Miscellaneous
“‑M22” Equipped with remote monitor switch
“‑M34” Provisions for headset microphone with belt switch
“‑M44” Remote speaker volume control
Table 2

4
HEADSET MICROPHONE WITH-BELT-SWITCH:
The “M34” Headset Microphones and Belt Switches are an additional option for
environments with a high level of ambient noise. Keying the belt switch overrides the
default mode of the intercom and enables audio transmission to all Primary units in the
intercom system. Figure 5 on page 11 illustrates a common intercom system where a
headset microphone and belt switch are used.
REMOTE POWER:
The “‑1” models are designed to provide power to “‑1” remote intercom units. The
AC‑powered main unit provides 12 Volts DC‑power and audio in the same cable to the
remote unit. The A “‑1” unit can provide power to just one remote unit. Figure 3 on page
9 illustrates this configuration.
PRE-AMPLIFIER:
The “‑8” models are equipped with a pre‑amplifier and are designed for use with
Secondary speaker units such as the AD‑SV‑25 Remote Speaker with Volume Control.
The “‑M44” option equips the “‑8” Primary unit with a knob for controlling the volume of
remote speakers such as the AD‑SF‑25 Flush Mount Speaker or the AD‑SS‑25 Swivel
Mount Speaker. Figures 6 on page 12 and 7 on page 13 illustrate intercom systems with
the “‑8” and “‑M44” options.
EXTERNAL-POWER-SOURCE:
The use of an external power source allows the user to configure intercom systems
made up of “‑1” DC‑powered Primary and Secondary units. Figure 8 on page 14
illustrates such a system.
SURGE PROTECTION:
Metal Oxide Varistor (MOV) devices are used to protect the audio lines. The intercom
must have Earth or Chassis Ground terminated to it to ensure surge protection.
The output amplifier of the Atkinson Dynamics intercom offers full short circuit
protection and overheat protection on AC models only.
FOOT PEDAL READY:
Models with the “‑2” option are designed for hands‑free activation of the Talk/Listen
switch. Figures 9 and 10 on pages 16 and 17, and 17 on page 23 show examples of
intercoms with this option. A heavy‑duty foot pedal (Model ADFP) is available through
Atkinson Dynamics.
AUXILIARY SIGNAL:
Models with the “‑3” option are equipped with a call button that provides a contact
closure for an attention‑getting auxiliary device, e.g., a strobe light. Figure 13 on page
19 demonstrates an intercom system with this option. Atkinson Dynamics offers a low
profile strobe light that is available with an amber or red lens, pipe or surface mount
configuration, and in three voltage variations.
ZONED SYSTEM REMOTE:
Models with the “‑6” option are designed for use in a zoned system. Figure 11 on page
17 illustrates a zoned intercom system. A Primary intercom can select (via a switch box)
to talk to any one or more remotes in a system. Each remote unit is equipped with a
Talk/Listen switch that enables communication to the Primary intercom, even when that
zone is not selected. Atkinson Dynamics offers 6‑zone and 12‑zone switch boxes.
MONITOR SWITCH:
Models with the “‑M22” option are equipped with a monitor on/off toggle switch. When
the monitor switch is in the on position, the remote unit becomes a Secondary and
defaults to talk mode. Figures 14 and 15 (pages 20 and 21) illustrate systems with this
feature.

5
B. Unpacking the Intercom
After unpacking the Atkinson Dynamics Intercom, examine it for damage that may
have occurred in transit. If the equipment has been damaged, do not attempt to
install or operate it, and file a claim immediately with the carrier stating the extent
of the damage. Carefully check all envelopes, shipping labels and tags before
removing or destroying them. Disposal of all shipping materials must be carried out
in accordance with national and local codes and standards. If any parts are missing,
please call Federal Signal Customer Support at +1 708‑534‑4756 or +1 877‑289‑
3246.
Before attempting to install the intercom, be sure that all parts listed in the KIT
CONTENTS LIST have been supplied.
C. Kit Contents List
Qty. Description Part Number
1 Resistor, 1K, 1W 101216
D. Mounting the Intercom
The selection of the mounting location for the device, its controls and the routing of the
wiring is to be accomplished under the direction of the facilities and the safety engineer.
NOTE
Intercoms supplied with flexible cords for connection to field wiring
are not intended for permanent mounting.
The intercom is intended to be mounted on any relatively flat and rigid surface
by the two mounting ears on the exterior of the housing. Figure 9 on page 15 is a
dimensional outline drawing showing the proper mounting configuration. The two
mounting ears are 13/32" diameter holes spaced 5.68" apart. Hardware for mounting
the intercom to the surface shall be provided by the installer.
This unit is heavy and should be mounted on a rigid surface
capable of supporting the weight of the intercom.
For shipboard applications, installations shall be in accordance with the United States
Coast Guard, Title 46 CRF, Parts 110‑113.
For units using the noise cancelling hand‑held microphone, install the supplied
microphone mounting clip on any rigid surface near the intercom. Avoid locating the
microphone where it may be exposed to excessive moisture or dust.
E. Electrical Connections
Plug each intercom into a nearby power source. Connect the audio inputs in parallel.
Audio wires should be sized properly by your licensed installation electrician for your
specified application.

6
Optional: A 1K, 1W resistor is included in a kit with each intercom. Installing the
resistor across the audio lines helps to reduce noise in certain environments. Only
one resistor needs to be installed on the lines for any system installation.
See Figures 1 through 19 starting on page 7 for typical intercom connections and
wiring information.
F. Service
Federal Signal will service your equipment or provide technical assistance with any
problems that cannot be handled locally.
Any units returned to Atkinson Dynamics for service, inspection, or repair must be
accompanied by a Return Material Authorization. This R.M.A can be obtained only
from the factory by calling (708) 534‑4756 or (877) 289‑3246.
Please give a brief explanation of the service requested or the nature of the
malfunction.
Address all communications and shipments to:
ATKINSON DYNAMICS
Service Department
2645 Federal Signal Drive
University Park, IL 60484‑3167
2. Replacement Parts.
Replace fuse with GMC‑1/2 only. DO NOT substitute.
Description Part Number
Cover plate gasket K8590013B
Knob, volume control K141A129A
Microphone assembly K137144A
PC Board, 12V, AD‑26 K2001878B
PC Board, 12V, AD‑26‑8‑M44 K2001896B
PC Board, 240VAC K2001875‑01
PC Board, 120 Vac, ‑1 models K2001885B
PC Board, 240 Vac, ‑1 models K2001885B‑01
Kit, potentiometer with on/off switch K8590236A
Kit, push button switch (12/24 V models) K8590242A
Kit, push button switch (120/240 V models) K8590241A
Resistor, 1K, 1W K101216A
Rubber boot, push button switch K288697A
Rubber boot, toggle switch K288696
Rubber boot, volume control K288A542A
Kit, potentiometer, 10K ohm K8590237A
Kit, toggle switch, 3PDT
(AD‑27A‑M34 and AD‑27A‑4‑M34 only)
K122342A
Kit, toggle switch, 3PDT K8590239B
Kit, pushbutton switch, 3PDT K8590288A
Kit, potentiometer, 1K ohm K8590289A
Voice Coil/Diaphragm Assembly, Series C K8590181A

7
G. Warranty.
Atkinson Dynamics guarantees their intercoms to be free of defects at the time of
delivery. If damage is found to be a factory defect, Atkinson Dynamics will warrant
all labor charges for repair for one full year, and all replacement parts for two full
years.

8
290A3693
BLK
WHT
BLK
WHT
AUDIO LINE TO OTHER INTERCOMS
1K
1WATT
AUDIO CABLE
REMOTE A REMOTE B
AUDIO CABLE
1
3
2
1
32
4
BLK
WHT
GRN
*
SEE POWER
CONNECTIONS
*
BLK
WHT
GRN
*
Reminders:
• Before installing remote intercoms, precautions should be taken to prevent feedback
between two or more remotes in close proximity and acoustically reflective areas.
• 16–20 gauge low voltage audio cable. Twisted pair not required.
• Shielded audio cable not required unless operating in high electromagnetic fields.
Ground one end of the shield to earth ground.
• Type of power cable depends on intercom model.
• 7 foot provided for audio and power.
Operating Principle:
• When one talks, all intercoms will hear.
• To talk to other stations, press the talk/listen
switch and speak into the speaker/micro‑
phone.
Release talk switch to listen.
NOTES:
1. Speaker/Microphone
2. Off/On/Speaker Volume Control
3. Talk/Listen Switch
4. “Call” Tone Switch
Power Remote A Remote B
12–18VDC AD‑26 AD‑26A
120V 50/60 Hz AD‑27 AD‑27A
22‑30VDC AD‑56 AD‑56A
240V 50/60 Hz AD‑57 AD‑57A
POWER CONNECTIONS:
BLK +DC Power 12/24V models
HOT 120/240V
WHT Common 12/24V models
Neutral 120/240V models
GRN Earth Ground 120/240V models only
1

9
BLK
WHT
GRN
*
290A3694
BLK
WHT
BLK
WHT
AUDIO
COMMON
REMOTE A REMOTE B
TO OTHER
REMOTES
1K
1WATT
1
3
5
2
1
32
4
BLK
WHT
GRN
*
SEE POWER
CONNECTIONS
*
Operating Principle:
• When one talks, all remotes will hear.
• To talk, press talk switch and speak into speaker/
microphone. Release talk switch to listen.
• To talk into hand‑held microphone, press talk
switch on microphone and speak into microphone
element.
NOTES:
1. Speaker/Microphone
2. Off/On/Speaker volume control
3. Talk/Listen switch
4. “Call” Tone push button switch
5. #137144 hand‑held, noise cancelling microphone
with push‑to‑talk switch
Power Remote A Remote B
12–18VDC AD‑26‑7 AD‑26A‑7
120V 50/60 Hz AD‑27‑7 AD‑27A‑7
22‑30VDC AD‑56‑7 AD‑56A‑7
240V 50/60 Hz AD‑57‑7 AD‑57A‑7
POWER CONNECTIONS:
BLK +DC Power 12/24V models
HOT 120/240V models
WHT Common 12/24V models
Neutral 120/240V models
GRN Earth Ground 120/240V models only
Reminders:
• Before installing remote intercoms, precautions should be taken to prevent feedback
between two or more remotes in close proximity and acoustically reflective areas.
• 16–20 gauge low voltage audio cable. Twisted pair not required.
• Shielded audio cable not required unless operating in high electromagnetic fields.
Ground one end of the shield to earth ground.
• Type of power cable depends on intercom model.
• 7 foot (2 meter) cable provided for audio and power.
2

10
290A3695
GRN
BLK
WHT
GRN
BLK
WHT
1K
1WATT
AUDIO
COMMON
(+) DC POWER
3/16-20 AWG
REMOTE A REMOTE B
1
3
2
1
32
BLK
WHT
GRN
*
SEE POWER
CONNECTIONS
*
Operating Principle:
• When one talks, the other stations will hear.
• To talk into the intercom, press the talk switch and
speak into the speaker/microphone. Release to
listen.
NOTES:
1. Speaker/Microphone
2. Off/On/Speaker volume control
3. Talk/Listen Switch
Power Remote A Remote B
Not applicable AD‑26‑1
120V 50/60 Hz AD‑27‑1
240V 50/60 Hz AD‑57‑1
POWER CONNECTIONS:
BLK +DC Power 12/24V models
HOT 120/240V models
WHT Common 12/24V models
Neutral 120/240V models
GRN Earth Ground 120/240V models only
3

11
GRN
BLK
WHT
GRN 1
BLK 3
WHT 2
GRN 1
BLK 3
WHT 2
AUDIO
COMMON
CONTROL
290A3696
PRIMARY "A" PRIMARY "B" SECONDARY
1
3
4
5
2
1
1
3
2
2
1K
1
WATT
SEE POWER
CONNECTIONS
BLK
WHT
GRN
*
*
BLK
WHT
GRN
*
BLK
WHT
GRN
*
Operating Principle:
• Primary normally listen to
Secondary.
• Secondary talks to Primary hands‑
free, without having to press a talk
switch.
• When any Primary talks, Secondary
hears. Other Primary will hear.
• To talk into Primary, press talk
switch and speak into speaker/
microphone. Release talk switch to
listen.
• To talk into hand‑held microphone,
press talk switch on microphone
and speak into microphone
element.
NOTES:
1. Speaker/Microphone
2. Off/On/Speaker volume control
3. Press‑to‑talk Switch
4. #137144 hand‑held, noise
cancelling microphone
5. 3‑conductor/16–22 gauge cable.
Use shielded cable in electrically
noisy areas. Ground one end of the
shield to “earth” ground. Ground
chassis of DC unit to ground.
Before installing remote intercoms, precautions should be taken to prevent feedback between
two or more remotes in close proximity and acoustically reflective areas.
Power Primary A Primary B Secondary
12–18VDC AD‑26C‑7 AD‑26C AD‑26D
120V 50/60 Hz AD‑27C‑7 AD‑27C AD‑27D
22‑30VDC AD‑56C‑7 AD‑56C AD‑56D
240V 50/60 Hz AD‑57C‑7 AD‑57C AD‑57D
POWER CONNECTIONS:
BLK +DC Power 12/24V models
HOT 120/240V models
WHT Common 12/24V models
Neutral 120/240V models
GRN Earth Ground 120/240V models only
4

12
290A3702B
BLK
WHT
BLK
WHT
AUDIO
COMMON
REMOTE
TO OTHER
INTERCOMS
1
3 6
5
2
4
SEE POWER
CONNECTIONS
BLK
WHT
GRN
*
*
BLK
WHT
GRN
*
1K
1
WATT
Operating Principle:
• When one talks, all remotes will hear.
• To talk into remote, press talk switch and
talk into speaker/microphone. Release
talk switch to listen. (The headset speaker
selector switch must be in “speaker”
position to hear received audio signal on
speaker.)
• To talk into headset, press belt “talk”
switch and talk into headset microphone.
Release belt switch to listen. (The selector
switch must be in “headset” position.)
NOTES:
1. Speaker/Microphone
2. Off/On/Speaker volume control
3. Talk/Listen switch
4. Headset/Speaker selector switch
5. “Call” push button switch
6. #137145 Headset with noise cancelling
microphone
Before installing remote intercoms, precautions should be taken to prevent feedback
between two or more remotes in close proximity and acoustically reflective areas.
Power Remote A
12–18VDC AD‑26A‑M34
120V 50/60 Hz AD‑27A‑M34
22‑30VDC AD‑56A‑M34
240V 50/60 Hz AD‑57A‑M34
POWER CONNECTIONS:
BLK +DC Power 12/24 V models
HOT 120/240 V models
WHT Common 12/24 V models
Neutral 120/240 V models
GRN Earth Ground 120/240 V models only
5

13
BLK WHT
BLK 1 WHT 2
AUDIO
200 FT. MAX.
COMMON
290A3742B
PRIMARY
REMOTE
SECONDARY
STATION
1
3
2
1
2
1K
1WATT
SEE POWER
CONNECTIONS
BLK
WHT
GRN
*
*
POWER CONNECTIONS:
BLK +DC Power 12/24V models
HOT 120/240V models
WHT Common 12/24V models
Neutral 120/240V models
GRN Earth Ground 120/240V models only
NOTES
1. Speaker/Microphone
2. Off/On Speaker Volume
Control
3. Talk/Listen Switch
4. Remote Secondary Station
Model AD‑SV‑25
Operating Principle:
1. Secondary station is both a
speaker and a microphone.
2. Primary is normally in “Listen”
mode until the talk button is
pressed to talk to remote.
3. Volume controls are for received
signal volume only. They do not
control transmitted signals.
POWER PRIMARY
12‑18VDC AD‑26‑8
22‑32VDC AD‑56‑8
120V 50/60 Hz AD‑27‑8
6

14
BLK WHT
BLK 1 WHT 2
AUDIO
200 FT. MAX.
COMMON
290A3743B
PRIMARY
SPEAKER
1
3
2
5
4
SEE POWER
CONNECTIONS
BLK
WHT
GRN
1K
1WATT
*
*
NOTES:
1. Speaker/Microphone
2. Off/On/Speaker volume control
3. Talk/Listen switch
4. Outgoing Volume Control
5. Speaker Model AD‑SS‑25 with
swivel mounting bracket or
Speaker Model AD‑SF‑25 with
holes in outer flange for flush
mounting
Operating Principle:
1. Secondary station is both a speaker and a microphone.
2. Primary is normally in “Listen” mode until the talk button is pressed to talk to remote.
3. Outgoing and incoming volumes are controlled by separate controls on Primary.
POWER CONNECTIONS:
BLK +DC Power 12/24 V models
HOT 120/240 V models
WHT Common 12/24V models
Neutral 120/240V models
GRN Earth Ground 120/240V models only
POWER PRIMARY
12‑18VDC AD‑26‑8‑M44
22‑32VDC AD‑56‑8‑M44
120V 50/60 Hz AD‑27‑8‑M44
240V 50/60 Hz AD‑57‑8‑M44
7

15
GRN
RED
WHT
BLK
GRN 1
RED 3
WHT 4
BLK 2
GRN 1
RED 3
WHT 4
BLK 2
AUDIO
+ DC POWER
COMMON
CONTROL
290A3744
PRIMARY "A" PRIMARY "B" SECONDARY
1
3
4
5
2
1
1
3
2
2
POWER
(+)
(
-
)
1K
1WATT
Operating Principle:
1. Primary normally listen to
Secondary.
2. Secondary talks to primary
“hands‑free”, without having
to press a talk switch.
3. When any Primary talks,
Secondary hears. Other
Primary will hear.
4. To talk into Primary, press
talk switch and speak into
speaker/ microphone.
Release talk switch to listen.
5. To talk into hand‑held
microphone, press talk switch
on microphone and speak
into microphone element.
NOTES:
1. Speaker/Microphone
2. Off/On/Speaker Volume
Control
3. Press‑to‑Talk Switch
4. #137144 Hand‑held, noise‑
cancelling microphone with
push‑to‑talk switch
POWER PRIMARY A PRIMARY B SECONDARY
12‑18VDC AD‑26C‑1‑7 AD‑26C‑1 AD‑26D‑1
22‑32VDC AD‑56C‑1‑7 AD‑56C‑1 AD56D‑1
8

16
9
290A4065
BLK
WHT
BLK
GRN
RED
WHT
1K
1WATT
AUDIO
COMMON
REMOTE A REMOTE B
1
3
2
BLK
WHT
GRN
*
SEE POWER
CONNECTIONS
TO OTHER
INTERCOMS
*
1
3
4
2
BLK
WHT
GRN
*
Operating Principle:
• When one talks, all intercoms will hear.
• To talk to other stations, press the talk/listen switch
and speak into the speaker/microphone. Release talk
switch to listen.
• To use external talk switch, close switch and speak into
the speaker/microphone.
NOTES:
1. Speaker/Microphone
2. Off/On/Speaker Volume Control
3. Talk/Listen Switch
4. Customer‑Supplied External Normally‑Open Talk/Listen
Switch, Momentary (e.g., foot switch)
Power Remote A Remote B
12‑18VDC AD‑26 AD‑26‑2
120V 50/60Hz AD‑27 AD‑27‑2
22‑30VDC AD‑56 AD‑56‑2
240V 50/60Hz AD‑57 AD‑57‑2
POWER CONNECTIONS:
BLK +DC Power 12/24V models
HOT 120/240V models
WHT Common 12/24V models
Neutral 120/240V models
GRN Earth Ground 120/240V models only

17
GRN
WHT
BLK
GRN
WHT
BLK
GRN
WHT
BLK
AUDIO
CONTROL
COMMON
290A4066
PRIMARY "A" PRIMARY "B" SECONDARY
3
4
2
1
3
2
2
1K
1
WATT
SEE POWER
CONNECTIONS
BLK
WHT
GRN
*
*
BLK
WHT
GRN
*
BLK
WHT
GRN
*
RED
BLU
1
Power Primary A Primary B Secondary
12‑18VDC AD‑26C‑2 AD‑26C AD‑26D
120V 50/60Hz AD‑27C‑2 AD‑27C AD‑27D
22‑30VDC AD‑56C‑2 AD‑56C AD‑56D
240V 50/60 Hz AD‑57C‑2 AD‑57C AD‑57D
Operating Principle:
• Primary normally listen to Secondary.
• Secondary talks to Primary hands‑free, without
having to press a talk switch.
• When any Primary talks, Secondary hears.
Other primary will hear.
• To talk into Primary, press talk switch and
speak into speaker/microphone. Release talk
switch to listen.
• Primary “A” can talk by pressing either the talk
switch or external switch (customer supplied).
NOTES:
1. Speaker/Microphone
2. Off/On/Speaker Volume Control
3. Press‑To‑Talk Switch
4. Customer‑Supplied External Normally‑Open
Press‑To‑Talk Switch, Momentary (e.g., foot
switch)
10
POWER CONNECTIONS:
BLK +DC Power 12/24 V models
HOT 120/240 V models
WHT Common 12/24 V models
Neutral 120/240 V models
GRN Earth Ground 120/240 V models only

18
POWER CONNECTIONS:
BLK +DC POWER 12/24 V models
HOT 120/240 V models
WHT Common 12/24 V models
Neutral 120/240 V models
GRN Earth Ground 120/240 V models only
Power Remote RA Remote RB Remote RC
12 VDC AD‑26‑6 AD‑26A‑6 AD‑26T‑6
120V 50/60Hz AD‑27‑6 AD‑27A‑6 AD‑27T‑6
240V 50/60Hz AD‑57‑6 AD‑57A‑6 AD‑57T‑6
** Refer to remote model number as an example for Primary.
290A4067B
REMOTE RB
PRIMARY DESK SET
PRIMARY WALL MOUNT
INTERCOM
4
5
7
SEE POWER
CONNECTIONS
BLK
WHT
GRN
*
*
*
**
**
REMOTE RA
4
8
6
3
5
BLK
WHT
GRN
BLK
WHT
GRN
REMOTE RC DESK SET
BLK
WHT
GRN
TO OTHER REMOTES
4
65
BLK
WHT
GRN
*
*
*
WHT
GRN
RED
BLK
BLK
RED
GRN
WHT
TALK COM.
TALK
LISTEN
LISTEN COM.
TALK COM.
TALK
LISTEN
LISTEN COM.
TALK COM.
TALK
LISTEN
LISTEN COM.
TALK COM.
TALK
LISTEN
LISTEN COM.
BLK
RED
GRN
WHT
BLK
RED
RC
RB
RA
GRN
WHT 2
3
2
9
9
1
1
6
NOTES:
1. Desk Set speaker (microphone is mounted on handset)
2. Desk Set speaker volume control
3. Handset earpiece volume control (mounted on back of case)
4. Speaker/Microphone
5. Off/On/Speaker volume control
6. Talk/Listen switch
7. “Call” Tone Switch
8. Primary switch box (customer supplied)
9. DPDT selector (toggle) switch (customer supplied)
Operating Principle:
1. Primary can select (via Primary switch box) to talk to any one or more remotes.
2. Any remote can initiate a call to Primary regardless of selector switch being on or
off. Remote must specify its location. Remotes cannot talk to other remotes.
3. To talk into intercom, press talk switch and speak into speaker/microphone.
Release talk switch to listen.
4. For Primary to talk to remote, select desired remote via selector switch, press talk
switch on handset microphone and talk into handset microphone.
11

19
NOTES:
1. Speaker/Microphone
2. Off/On/Speaker volume control
3. Outgoing Volume Control
4. Speaker Model AD‑SS‑25 with swivel
mounting bracket or Speaker Model
AD‑SF‑25 with holes in outer flange for
flush mounting
5. PTT (press‑to‑talk) switch
(customer supplied)
OPERATING PRINCIPLE:
1. Primary station is both a speaker and a microphone.
2. Primary is normally in “Listen” mode until the PTT (press‑to‑talk) switch is pressed to
talk to Secondary.
3. Outgoing and incoming volumes are controlled by separate controls on Secondary.
4. Secondary talks to Primary hands‑free, without having to press a talk switch.
POWER CONNECTIONS:
BLK +DC Power 12/24 V Models
WHT Common 12/24 V Models
POWER SECONDARY
12‑18VDC AD‑26D‑8‑M44
GRN WHT
RED BLK
GRN 1 WHT 2
AUDIO
CONTROL
200 FT. MAX.
COMMON
290A4068
SECONDARY
PRIMARY SPEAKER
1
2
4
3
SEE POWER
CONNECTIONS
BLK
WHT
1K
1WATT
*
*
5
PRIMARY
SPEAKER
12

20
Operating Principle:
• When one talks, all intercoms will hear.
• To talk to other stations, press the talk/listen switch
and speak into the speaker/microphone. Release talk
switch tolisten.
• Pressing the call button on remote A provides a
contact closure for an attention‑getting auxiliary
signaling device, e.g. a strobe light.
NOTES:
1. Speaker/Microphone
2. Off/On/Speaker Volume Control
3. Listen/Talk Switch
4. “Call” Switch
5. Customer‑Supplied Auxiliary Signaling Device
(e.g., strobe light)
Power Remote A Remote B
12‑18VDC AD‑26‑3 AD‑26
120V 50/60Hz AD‑27‑3 AD‑27
22‑30VDC AD‑56‑3 AD‑56
240V 50/60Hz AD‑57‑3 AD‑57
POWER CONNECTIONS:
BLK +DC Power 12/24V models
HOT 120/240V models
WHT Common 12/24V models
Neutral 120/240V models
GRN Earth Ground 120/240V models only
BLK
AUDIO CABLE AUDIO CABLE
TO OTHER
INTERCOMS
AUDIO
LINE
RED
WHT
BLK
-
POWER
+
POWER
WHT
GRN
290A4069
REMOTE "A" REMOTE "B"
AUXILLIARY
SIGNALING DEVICE
1
5
3
2
1K
1
WATT
SEE POWER
CONNECTIONS
BLK
WHT
GRN
*
*
BLK
WHT
GRN
*
1
3
2
4
13
This manual suits for next models
3
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