Atkinson Dynamics AD-28LD-MV Quick guide

INSTALLATION AND SERVICE INSTRUCTIONS
MODEL AD-28LD-MV
CALL
WARNING: DISCONNECT POWER BEFORE REMOVING COVER
TALK
LISTEN
290A3077B
2562445A
REV. A 1108
Printed in U.S.A.
UNIVERSITY PARK, IL USA

-2-
INSTALLATION AND SERVICE INSTRUCTIONS
FOR
MODEL AD-28LD-MV
SAFETY MESSAGE TO INSTALLERS, USERS AND
MAINTENANCE PERSONNEL
It is important to follow all instructions shipped with this prod-
uct. 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.
The selection of the mounting location for the device, its controls
and the routing of the wiring is to be accomplished under the direc-
tion of the facilities engineer and the safety engineer. In addition,
listed below are some other important safety instructions and precau-
tions 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mainte-
nance 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main-
tenance must be performed by a trained electrician in
accordance with NEC guidelines and local codes.
Failure to follow all safety precautions and instructions may re-
sult in property damage, serious injury, or death to you or others.

Figure 1.
-3-
A. GENERAL FEATURES.
 TheAD-28LD-MVintercomisa2-waycommunicationsdevice
designed for light duty industrial applications. Nominal operating
voltagesinclude120/240Vac,50/60Hzand24Vdc.Voltagechanges
forthe120/240VACareinternallyswitchselectableandtheACline
isfusedwitha1/2amp250volttypeGMCfuse.Theunitalsooffers
internally selectable balanced or unbalanced line operation, trans-
formerisolatedaudioinputsandinternallyselectableMasterorSlave
modecongurations.Acallbuttonwithremotecalldrycontactsis
alsofactorysuppliedintheunit.TheAD-28LD-MVhasaType1en-
closureandisaULListedsignalappliance.
MASTERMODE:
 EachintercomcanbeconguredasaMasterunit(Push-to-Talk)
oraSlaveunit(Push-to-Listen)bychangingtheMAS/SLAjumper
(J3)ontheprintedcircuitboard(seegure1).Theintercomcomes
fromthefactorysetintheMaster(MAS)mode.
 IntheMastermodetheintercomactsasanamplier,constantly
broadcastingoveritsspeakeranysignalthatitreceivesonthesignal
lines.HoldingdowntheListen/Talkswitchchangestheunitfroma
speakertoamicrophone(seegure2).Theintercomwillnowtrans-
mitoverthesignallinestoadditionalintercom(s)alsosetinthe
R6
C11
REPLACE
CM
TYPE
J2
240VAC
ONLY
SAME
SW1
FUSE
WITH
GMC-1/2
1/2A
CR1
+
J1
T3
120VAC
1
C2
C1
R1
CR2
P
K1
C5 C9
C4 C8
C7
R18 24VDC
CALL
IN/OUT
CONTROL
GROUND
CONTACT
SPEAKER
2001290 A
K2
R19
EXT
REMOTE
REMOTE
-
+
IC3
C21
T2
CR7
CR6
CR5
CR4
C13
J4
>BAL
>UNB
J5 R17
R16
Q3
CR3
R15
C14
>MAS
>SLA
J3
R12
R13
R14
S
J6
R11
R10
R3
R2
C10
Q2
R8
R9
R7
C20
C19
C18
C17
R34
J7
C22 O
CR8
R33
R31
R32
R30
R29
R28
R27
R26
R25
R21
R22
R24
R23
T1
C3 C6
Q1 IC1
C12 R5
R4
C16
IC2
C15
R20
V
L
W
I
T
C
H
S
K
R
250V
F1
H1
H2
TO SPEAKER
FUSE
CLASS I WIRING
120VAC/240VAC
SWITCH
TO SWITCH
MASTER/SLAVE
JUMPER
VOLUME
CONTROL
CLASS II WIRING
BAL/UNBAL
JUMPER(2)
290A3076

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Figure 2.
mastermode.Whentheswitchisreleaseditwilldefaultbacktothe
ListenorSpeakermode,allowingtheusertoreceiveanymessages
transmittedbacktoit.Theoutputamplieroffersfullshortcircuit
protection and over heat protection.
SLAVEMODE:
 Someapplicationsmayrequirethattheintercomconstantly
transmit(i.e.,actasamicrophone)asopposedtoconstantlyreceive
(i.e.,actasaspeaker).Toaccomplishthistheintercommustbe
switchedintotheSlave(Push-to-Listen)mode.
WARNING
Disconnectpowertotheintercombeforeanyinstallation,
maintenance, or configuration changes are performed.
 MovetheJ3jumperblockontheP.C.boardfromtheMAStoSLA
position(seegure1).Thiscanbedoneusinglongnosepliers,pull-
ingtheblockoffthe“MAS”andcenterpositionandplacingitonthe
“SLA”andcenterposition.
 WhenhookedtoaMasterunititmaybenecessarytooverride
theSlaveunitinorderfortheMasterunittobeabletotransmit.The
remotecontrolandgroundlinesmustbeconnectedbetweentheMas-
terandtheSlaveunit.ParagraphG.WIRINGDIAGRAMScontains
wiring diagrams of typical intercom configurations.
CALL
WARNING: DISCONNECT POWER BEFORE REMOVING COVER
TALK
LISTEN
290A3077B
UNIVERSITY PARK, IL USA

-5-
REMOTECONTROL:
 Remotecontrolisusedtochangetheoperationmodeofaremote
intercomfromlistentotalkorfromtalktolistenuponactivationof
alocalintercom.ThewiringdiagramsectionillustratesMaster/Slave
InstallationandUsingFootSwitchesDiagrams.(Seegures5and6.)
 NormallyopenfootswitchescanalsobeconnectedtotheRemote
Controllineandgroundinordertoallow“handsfree”operationofthe
listen/talkfunctions.
CALLBUTTONANDCALLDRYCONTACTSTOEXTERNALDE-
VICE:
 Depressingthecallbuttonsendsa1kHztoneontothesignal
lines.Allunitslisteningtothelinewillthenbroadcastthissignalas
acall.Depressingthecallbuttonalsoclosesanormallyopendrycon-
tactratedat0.4amps@125Vacor1.25amps@24Vdc.Thiscontact
can be used to trigger a remote sounder or light in order to accent the
call feature. The wiring diagram illustrates how an external light or
horncanbewiredintoaugmentthecalltone.(Seegure7.)
CAUTION
The call signal is substantially louder than normal voice mes-
sages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.
24Vdc:
 TheAD-28LD-MViscapableofsendingDCpowertoanotherunit
thatismountedinaremotelocationwithoutlocalpower.24Vdcis
availablefrompositions6and7ofterminalblockJ7.Itcanberun
alongwiththesignallinestoanintercominaremotelocation.Only
one unit should share the power supply of another unit in any instal-
lation.Figure8inthewiringdiagramssectionshowshowtwointer-
comscanbehookedupifnoremotepowerisavailable.
CAUTION
Ifanintercomisintendedtoberunoffofaseparate24Vdc
supply,theoutputmustbelimitedto24Vdc,760mAoutput.

-6-
Figure 3.
ISOLATEDBALANCED/UNBALANCEDLINES:
The audio signals are transmitted over a wire pair using balanced
line technology. This means each wire carries a signal that is opposite
inpolarityoftheother.Attheinputoftheintercomisanisolated
balanced line transformer. This transformer subtracts the two signals
from each other providing an output free of noise generated onto the
wires by some other noise source such as a motor or light fixture near
the wires.
The isolation provided by the transformer means that the grounds
of the units are not connected by the audio lines. Therefore, ground
loops and other problems caused by non-isolated systems are avoided.
The polarity of the audio lines between the + and - signal terminals
need not be maintained.
 Ashieldedcablecanbeusedininstallationswhereextreme
problems from interference are suspected. The shield should always
be connected to the ground of only one of the intercoms. Connecting
the shield to ground at both ends will cause ground currents to travel
through the shield which could cause hum in the system.
 Thereareseveraldiagramsinthebackofthemanualtoaidin
wiring intercoms together. The wiring diagram section illustrates bal-
anced and unbalanced line interconnection along with how a shielded
audiocablecanbeused.(Seegures5through12.)Italsoillustrates
290A3078
24VDC IN/OUT
GROUND
GROUND
CLASS I WIRING CLASS II WIRING
REMOTE CONTROL
REMOTE SPEAKER
EXT CALL
CONTACT
+
-
COMMON
J2
J7
PHASE

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multiple intercom interconnections.
MODELAD-28LD-MV
SPECIFICATIONS
OperatingVoltage24Vdc,120Vacand240Vac50/60Hz
CurrentDraw Voltage Operating Standby
    24Vdc 120mA 60mA
    120Vac 80mA 60mA
    240Vac 40mA 30mA
CAUTION:The24Vdcinputmustbelimitedto760mAoutifrun
from a supply.
AmplierSpecications
 FrequencyResponse(–6dB)150Hzto12kHz
 InputImpedance 3400ohms
 Max.OutputVoltage
  SineWave:
   BalancedOutput 15Vrms
   UnbalancedOutput 7.5Vrms
  SquareWave:
   BalancedOutput 19Vrms
   UnbalancedOutput 9.5Vrms
SpeakerRating 2watts
SpeakerImpedance 8ohm
TemperatureRange −31°Fto+150°F
 (–35°Cto+66°C)
FuseTypeGMC-1/2 1/2A,250V
CallSwitchContactRating 400mA@125Vac
     1.25A@24Vdc
AgencyApprovals UL,Type1
Weight
 Shipping  3lb,9oz
 Net   3lb,2oz
HousingDimensions 6.87"Wx8.00"Hx3.05"D
ConduitEntrances Dual1/2"-3/4"Knockouts
HousingMaterial Aluminum
Color    Black

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B. UNPACKING.
 AfterunpackingtheModelAD-28LD-MV,examineitfordamage
that may have occurred in transit. If the equipment has been dam-
aged, do not attempt to install or operate it, 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.
 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 InstructionManual 2562445
1 Resistor,1K,1W K101216
D. MOUNTING.
CAUTION
The selection of the mounting location for the device, its con-
trols and the routing of the wiring is to be accomplished under
the direction of the facilities and the safety engineer.
The intercom is intended to be mounted on any relatively flat and
rigid surface by the four mounting holes in the interior of the housing.
Figure4isadimensionaloutlinedrawingshowingthepropermount-
ingconguration.Thefourmountingholesare0.202indiameterand
aredesignedtoaccepta#10mountingscrew.Hardwareformounting
the intercom to the surface is left up to the installer. The intercom
housinghastwocombination1/2"-3/4"knockoutsinthebottom.When
installingtheconduittotheseopenings,choosingthesizeandtypeof
connector is left up to the installer.
E. ELECTRICAL CONNECTIONS.
WARNING
Donotconnectwireswhenpowerisapplied.
The intercom has two wiring compartments, one for Class I wir-
ingandthesecondforClassIIwiring.Allwiringtotheintercomis
terminatedattwopcboardmountedterminalblocksprovided.The
ACPhaseandCommon,alongwithEarthGround,arelandedina

-9-
three-positionterminalblock(J2)intheClassIwiringcompartment.
The signal lines, remote control lines, remote power, and call dry con-
tactsarelandedinaseven-positionterminalblock(J7)intheClassII
wiring compartment. The two wiring sections are isolated by a fishpa-
per barrier.
WARNING
Disconnectpowertotheintercombeforeanyinstallation,
maintenance, or configuration changes are performed.
 TherearethreejumpersshownonthePCboardinFigure7that
may need to be moved depending on the desired operation of the
intercom.J4andJ5areforoperatingtheintercomineitherabal-
anced signal line or unbalanced signal line configuration. These must
be moved together as a pair. They are factory set in the balanced line
position.J3isforconguringtheintercomaseitheramasterorslave
device. The intercom is factory set in the master position.
There is a switch on the board, in the Class I wiring compart-
ment,toconguretheoperationoftheboardfrom120Vacto240Vac.
Theswitchisfactorysetfortheintercomtooperateon120Vac(see
gure3).
 Seegures5through12fortypicalintercomcongurations.
F. SERVICE.
CAUTION
Anymaintenancemustbeperformedbyatrainedelectrician
in accordance with NEC guidelines and local codes.
1. General.
CAUTION
The call signal is substantially louder than normal voice mes-
sages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.
  FederalSignalwillserviceyourequipmentorprovidetechni-
cal assistance with any problems that cannot be handled locally.
  AnyunitsreturnedtoFederalSignalforservice,inspection,or
repairmustbeaccompaniedbyaReturnMaterialAuthorization.
ThisR.M.AcanbeobtainedfromthelocalDistributororManufac-
turer’sRepresentative.

Figure 4.
-10-
  Atthistimeabriefexplanationoftheservicerequestedorthe
nature of the malfunction, should be given.
  Addressallcommunicationsandshipmentsto:
  ServiceDept.
  AtkinsonDynamics
  FederalSignalCorp.
  2645FederalSignalDr.
  UniversityPark,IL60466-3195
 2. Replacement Parts.
WARNING
ReplacefusewithGMC-1/2only.DONOTsubstitute.
Description  PartNumber
Resistor,1K,1W K101216
Fuse,GMC-1/2 K148A155
Mini-jumpers  K139A209
PCBA    K2001290
Switch    K122283
Speaker   K132141
8.00
FRONT BACK
BOTTOM
CLASS I WIRE
ENTRY
CLASS II WIRE ENTRY
6.87
3.50
COMBINATION 1/2"-3/4" KNOCK-OUT
3.05
1.40
7.125
5.50
290A3079B
4 x .202
CALL
WARNING: DISCONNECT POWER BEFORE REMOVING COVER
TALK
LISTEN
UNIVERSITY PARK, IL USA

-11-
Figure 5.
290A3080B
24 VDC
GROUND
REMOTE
AUDIO +
AUDIO -
DRY CONTACT
DRY CONTACT
24 VDC
GROUND
REMOTE
AUDIO +
AUDIO -
DRY CONTACT
DRY CONTACT
NEUTRAL
HOT
EARTH GND.
NEUTRAL
HOT
EARTH GND.
INTERCOM I
AD-28LD-MV MASTER
J7
J2 J2
J7
INTERCOM II
AD-28LD-MV SLAVE
MASTER/SLAVE INSTALLATION
1K
1 WATT
7
6
5
4
3
2
1
3
2
1
3
2
1
7
6
5
4
3
2
1
AC AC
Master Slave Installation
 Inthisinstallation,theMasterisconstantlybroadcastingaudiofromthe
 Slave.Pushingthelisten/talkswitchoneitherunitforcestheSlaveinto
 thelistenmodeandtheMasterintothetalkmode.TheMAS/SLAjumper
 mustbeplacedintheSLAmodeforthisoperationontheslaveunit.
Using Foot Switches
 Usingnormallyopen,simplecontactclosurefootswitches(customer
 supplied)allowsfortotalhandsfreeoperationofthelisten/talkfunctions.
Figure 6.
290A3081B
24 VDC
GROUND
REMOTE
AUDIO +
AUDIO -
DRY CONTACT
DRY CONTACT
24 VDC
GROUND
REMOTE
AUDIO +
AUDIO -
DRY CONTACT
DRY CONTACT
NEUTRAL
HOT
EARTH GND.
NEUTRAL
HOT
EARTH GND.
INTERCOM I
AD-28LD-MV MASTER
J7
J2 J2
J7
INTERCOM II
AD-28LD-MV SLAVE
USING FOOT SWITCHES
1K
1 WATT
7
6
5
4
3
2
1
3
2
1
3
2
1
7
6
5
4
3
2
1
AC AC
FOOT SWITCH
N.O.
FOOT SWITCH
N.O.
G. WIRING DIAGRAMS.

-12-
Using Call Dry Contacts with AC
The dry contacts can be used to switch devices such as an auxiliary sound
or light when call is depressed. The maximum ratings for the dry contacts
 are.4amps@125VACand1.25amps@24VDC.Thismethodassuresa
call is received even when the volume on one of the intercoms is turned all
the way down.
Figure 7.
290A3082B
24 VDC
GROUND
REMOTE
AUDIO +
AUDIO -
DRY CONTACT
DRY CONTACT
24 VDC
GROUND
REMOTE
AUDIO +
AUDIO -
DRY CONTACT
DRY CONTACT
NEUTRAL
HOT
EARTH GND.
NEUTRAL
HOT
EARTH GND.
INTERCOM I
AD-28LD-MV MASTER
J7
J2 J2
J7
INTERCOM II
AD-28LD-MV SLAVE
USING CALL DRY
CONTACTS WITH AC
1K
1 WATT
7
6
5
4
3
2
1
3
2
1
3
2
1
7
6
5
4
3
2
1
POWER POWER
AC AC
No Remote Power Available
 IntercomIsuppliestheDCpowertothesecondintercom.Earthground
must be wired on the second unit.
Figure 8.
290A3083B
24 VDC
GROUND
REMOTE
AUDIO +
AUDIO -
DRY CONTACT
DRY CONTACT
24 VDC
GROUND
REMOTE
AUDIO +
AUDIO -
DRY CONTACT
DRY CONTACT
NEUTRAL
HOT
EARTH GND.
NEUTRAL
HOT
EARTH GND.
INTERCOM I
AD-28LD-MV MASTER
J7
J2 J2
J7
INTERCOM II
AD-28LD-MV SLAVE
NO REMOTE POWER
AVAILABLE
1K
1 WATT
7
6
5
4
3
2
1
3
2
1
3
2
1
7
6
5
4
3
2
1
AC

-13-
Basic Balanced Line System
This is a simple system with only two conductors connected between the
 units.ACpowerisutilizedatbothsites.TheUnitisfactorycongured
 forbalancedlineoperation.(NOTE:bothjumpersinBALposition.)
Figure 9.
290A3084B
24 VDC
GROUND
REMOTE
AUDIO +
AUDIO -
DRY CONTACT
DRY CONTACT
24 VDC
GROUND
REMOTE
AUDIO +
AUDIO -
DRY CONTACT
DRY CONTACT
NEUTRAL
HOT
EARTH GND.
NEUTRAL
HOT
EARTH GND.
INTERCOM I
AD-28LD-MV MASTER
J7
J2 J2
J7
INTERCOM II
AD-28LD-MV SLAVE
BASIC BALANCED
LINE SYSTEM
1K
1 WATT
7
6
5
4
3
2
1
3
2
1
3
2
1
7
6
5
4
3
2
1
AC AC
Shielded Balanced Line System
This system offers maximum isolation from noise over long runs. The
 shieldshouldonlybegroundedatoneside.ACpowerisutilizedatboth
 sites.Theunitisfactoryconguredforbalancedlineoperation.(NOTE:
 bothjumpersinBALposition.)
Figure 10.
290A3085B
24 VDC
GROUND
REMOTE
AUDIO +
AUDIO -
DRY CONTACT
DRY CONTACT
24 VDC
GROUND
REMOTE
AUDIO +
AUDIO -
DRY CONTACT
DRY CONTACT
NEUTRAL
HOT
EARTH GND.
NEUTRAL
HOT
EARTH GND.
INTERCOM I
AD-28LD-MV MASTER
J7
J2
J7
INTERCOM II
AD-28LD-MV SLAVE
SHIELDED BALANCED
LINE SYSTEM
1K
1 WATT
7
6
5
4
3
2
1
3
2
1
3
2
1
7
6
5
4
3
2
1
J2
AC AC

-14-
Basic Unbalanced Line System
 Thiscongurationisusedwhenhookingtootherproductsonthemarket.
This system does not offer the same level of noise isolation as a balanced
 linesystemandshouldonlybeusedwhenhookingtoexistingdevices.The
 neighboringjumpersonthecircuitboardmustbechangedfromtheBAL
 positiontotheUNBpositionfortheseinstallations(seegure1).
290A3086B
24 VDC
GROUND
REMOTE
AUDIO +
AUDIO -
DRY CONTACT
DRY CONTACT
NEUTRAL
HOT
EARTH GND.
INTERCOM I
AD-28LD-MV MASTER
J7
J2
BASIC UNBALANCED
LINE SYSTEM
1K
1 WATT
7
6
5
4
3
2
1
3
2
1
AC
AUDIO
GROUND
CABLE
AC
Figure 11.

Multiple Intercoms
 Multipleintercomscanbetiedtooneline.Depressingtalkonanyunit
 willbroadcastaudiooverallotherunits.(NOTE:onlyonelineresistor
 needstobeinstalledonthelineforanyinstallation.)
290A3087B
24 VDC
GROUND
REMOTE
AUDIO +
AUDIO -
DRY CONTACT
DRY CONTACT
24 VDC
GROUND
REMOTE
AUDIO +
AUDIO -
DRY CONTACT
DRY CONTACT
NEUTRAL
HOT
EARTH GND.
NEUTRAL
HOT
EARTH GND.
INTERCOM I
AD-28LD-MV MASTER
J7
J2 J2
J7
INTERCOM 2
AD-28LD-MV SLAVE
MULTIPLE INTERCOMS
1K
1 WATT
7
6
5
4
3
2
1
3
2
1
3
2
1
7
6
5
4
3
2
1
AC
AC AC
DRY CONTACT
DRY CONTACT
AUDIO -
AUDIO +
REMOTE
GROUND
24 VDC
NEUTRAL
HOT
EARTH GND.
DRY CONTACT
DRY CONTACT
AUDIO -
AUDIO +
REMOTE
GROUND
24 VDC
NEUTRAL
HOT
EARTH GND.
INTERCOM 3
310-MV MASTER
INTERCOM 4
310X-MV SLAVE
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
AC
-15-
Figure 12.