12.PUBLIC ADDRESS SYSTEM

12.00.00 PUBLIC ADDRESS SYSTEM

 

12.01.00 General Requirements

 

12.01.01 A  Public  Address  System(PAS)common  for station shall

 

         be supplied by the Bidder to cover all operational areas

 

         of the  complete plant. 

 

12.01.02 Public Address System shall consist of zones,  sub-zones

 

         and  exchanges  to  interface  all  four  zones   among

 

         themselves  and also with employer’s existing  telephone

 

         exchange.   The  major zones and sub-zones shall  be  as

 

         under.

 

(i)  Zone 1 for unit area(35 per unit/70 for both unit)

 

         (ii) Zone 2 for common plant area (20 point)

        

             

12.01.03(a)Each point shall be provided with a handset station and

 

         its  associated  loudspeaker.   The actual locations  of 

 

         the handset stations/loudspeakers  shall be as finalized

 

         during detailed engineering.

 

     (b) The  Bidder shall provide all required cables,  junction

 

         boxes,   earth  wire  and  accessories   like   standard

 

         brackets, nut-bolts, glands, lugs, conduit sleeves  etc.

 

         as   required  to  complete  the  installation   of   all

 

         equipments supplied in the PAS.

 

12.02.00 System Description

 

 

12.02.01 PAS  shall  have two modes, i.e. Paging  mode  and  Party

 

         mode.  Each of the two modes shall be open line,  common

 

         talking type.  Paging mode shall be used for locating  a 

 

         person and for general instructions. Party mode shall be 

 

         used   for  conversation  between  individuals   without 

 

         broadcasting the same over the  loudspeaker.

 

12.02.02 Whenever  the `Press to Page’ push button is pressed  on

 

         any  of the handset stations, a pleasant chime shall  be 

 

         broadcast  over  all  the  loudspeaker  except  the  one

 

         associated   with  that  handset  station   to   attract

 

         attention.  Conversation, in paging mode shall be  heard

 

         over all loudspeakers except the loudspeaker  associated

 

         with  the  handset station whose  `Press to  Page’  push

 

         button is being held in pressed condition.  When  `Press

 

         to Page’ push button is released the associated  handset

 

         shall  return to party mode. When a handset  station  is

 

         being  used  for party mode its  associated  loudspeaker

 

         shall be free top receive all paging calls. However, the

 

         operator   shall  have  the  option  of  silencing   the

 

         associated   loudspeaker   by   pressing    `Loudspeaker

 

         mute’  push  button, should be find  it  disturbing  his

 

         conversation  on  party  mode.   The  loudspeaker  shall

 

         return  to  normal  operation  automatically  when   the 

 

         `loudspeaker    mute’   push   button    is    released. 

 

         Simultaneous operation on both modes, i.e. some handsets

 

         on  party  channel and some handsets on  paging  channel,

 

         shall be possible without any cross talk between the  two

 

         channels.  Further, suitable indication of `Power supply

 

         On’  and `party channel busy’ shall be provided on  hand

 

         set stations.

 

12.02.03 Portable  type  handsets with multipin  plugs  shall  be 

 

         used at certain locations where operational personnel are

 

         not  present normally. Necessary sockets, wiring,  etc.,

 

         shall  be  provided  at  these  locations.  Quantity  of

 

         handsets shall be 5 Nos. for unit area & 5 Nos. for common

 

         area.  No.of sockets shall be 10 Nos. for unit area,  10

 

         Nos.for  CHP , 5 Nos. for common area and 5 for AHP  area. 

 

         The  location, details  shall  be  finalised   during  

 

         detailed  engineering  stage  &  shall be  subject  to 

 

         MPPGCL’s  approval.

 

12.02.04 Inter Zone Communication

 

         Each  of  the  zones, i.e.unit  common  plant  and  coal

 

         handling  plant  are  shall be connected  to  a  central

 

         exchange.   It shall be possible from a station  in  one

 

         zone  to be connected to another station of a  different

 

         zone  through a master control units, to be  located  in

 

         unit  control  desk.  Another master  control  unit,  in

 

         parallel with the earlier one shall be located in  shift

 

         in  change  room.   Further,  suitable  interface   with

 

         telephone  exchange (existing)shall be provided so  that

 

         it shall be possible to communicate with any station  in

 

         any  zone through master control unit from a  telephone. 

 

         The  central exchange shall have the capacity of  future

 

         expansion in No.of  stations, zones, master control unit

 

         and exchange.

 

12.02.05 Self Diagnostic Facility shall be provided.

 

12.03.00  Handset Stations

 

         Each  handset  station shall be  capable  of  continuous

 

         satisfactory operation at ambient temperature of 55 Deg.C

 

         Handset transmitter/receiver shall be  noise  canceling

 

         type  and shall have filters to protect from dust.   All

 

         switches and push buttons on the  handset stations shall

 

         be   excapsulated  contact  type.   Desk  mounting  type

 

         (indoor) and wall mounting column type(outdoor)  handset

 

         stations  shall have a degree of protection as  per  the 

 

         requirements specified in GTR of this specification.

 

12.04.00 Amplifiers

 

         The  PAS  shall be of distributed amplifier  type,  i.e.

 

         each  loudspeaker shall have a separate power  amplifier

 

         of  its  own  which may be located  in  the  associated

 

         handset  station enclosure or in a  separate  enclosure. 

 

         Amplifiers shall be solid state, Class B push-pull type,

 

         fully  conforming to IS:1301 and IS:10426 or  equivalent

 

         international standard, with modular construction  (card

 

         type with edge connectors). Each amplifier shall have 0-

 

         100%  volume control setting, with bass cut  filter  and

 

         external   short  circuit  protection.    Electronically

 

         operated  idle power cutoff feature shall  be   provided

 

         for both pre-amplifiers and  power amplifiers.

 

12.05.00 Loudspeakers

 

         Indoor loudspeakers shall be cone type housed in  sturdy

 

         metal  cabinet  treated  with  acoustic  undercoats   to

 

         prevent resonance and shall be suitable for  wall/column

 

         mounting.  Outdoor loudspeakers shall be horn type.  The

 

         mounting brackets shall be with adjustable base suitable

 

         for vertical and horizontal orientation.  Acoustic hoods

 

         shall be provided for handset stations located in  noisy

 

         areas  like BFP, turbine firing floors, mills fans  etc. 

 

         The  design  noise  level  within  the   hood  shall  be 

 

         limited to a maximum of 60 dB S.I.L.

 

12.06.00 Power Supply & Grounding

 

         The Bidder shall provide stable, reliable and  regulated

 

         power  supply  and grounding system as required  by  the

 

         system. Grounding shall be  as per Indian Standard.

 

12.07.00  Technical Parameters

 

         PAS shall conform to the following.

 

12.07.01  For  overall installation Bandwidth (+/-3 dB  shall  be 

 

         400-6000 Hz.  

 

12.07.02  For Amplifiers Bandwidth (+/- 3 dB) shall be  200-10000

 

         Hz; Total Harmonic distribution shall be less than 1% at

 

         rated output at  1 KHz; Signal/Noise ratio shall be   60

 

         dB.

 

12.07.03 For  Microphone Bandwidth (+/- 3 dB) shall  be  200-7000

 

         Hz; Type shall be noise canceling type.

 

12.07.04 For  outdoor wall/column mounted horn type  loudspeakers

 

         capacity  and bandwidth (+/- 3 dB)shall be  15  W  (RMS)

 

         and 200-7000 Hz respectively.

 

12.07.05 For  indoor wall/column mounted cone type  loudspeakers

 

         capacity  and bandwidth (+/- 3 dB)shall be  4 W  (RMS)

        

         and 200-7000 Hz respectively.

 

12.08.00 Signal Loop Length

 

         Signal Loop Length (Cable) shall be as per requirement.

 

12.09.00 Cables, Junction Boxes & Other Accessories

 

         The  bidder shall supply all cables, junction boxes  and

 

         other accessories required for PAS.  All cables shall be 

 

         standard copper conductors, PVC insulated, extruded  PVC

 

         inner  sheathed, overall PVC sheathed &  shielded.   All

 

         junction  boxes  and  accessories  shall  meet  all  the 

 

         specification  requirements  as  specified  at  relevant

 

         clause of this specification.

 

12.10.00 Testing, Calibration & Maintenance Equipment

 

      (a) Digital Multimeters     -  4

      (b) Megger                  -  1

      (c) Stand Tool Box (with    -  2

          Multipurpose tool box,

          Screw drivers, spanners,

          Allen key, nose plier,

          Files etc.