Open Museum Archive

PABX3 Telephone Exchange
Object ID2617
Date0000-00-00
Works No
Accession NoIF:2008:560
StatusIn service
Category Telephone
Collection IDTelecommunications
Made ByGEC Telecommunications Ltd
Made InCoventry, England
DescriptionTwo rack PABX3 from Luton Town Hall - ex Nene Valley Railway, Peterborough
Location
ConditionWorking with faults
History
2007-11-10

Originally installed in Luton Town Hall.

The exchange was removed to the Nene Valley Railway in the 1980s where it remained In Service until 2008 before moving to the museum.

Conservation/ Maintenance History
Commissioning
2009-04-18

Exchange commissioned with two final and two 1st group selectors enabling two simultaneous calls.

Multiple faults found.
One ringer OOS
3 faulty final selectors
3 faulty 1st group selectors
OG Relay set not working
Speaking clock N/A


General Maintenance
2011-09-16

Work carried out by D. Williams.

1) F/S D6 off normal - wipers bent - adjusted
2) F/S D6 Not stepping vertical - heat coil blown - replaced
3) Fuse alarm lamp not working - bulb failure - bulb replaced
4) Fuse alarm lamp sometimes not working - fuse alarm fuse loose - fuse screw tightened
5) G/S E1 dropping out level 2 - wiper cord detached at wiper - re-soldered & bank cleaned
6) intermittent no dial tone - G/S start circuit U-points dirty on unused G/S positions - cleaned all spare U-points (U21-23)
7) Ext 290 not ringing from F/S C6 - wipers adjusted and bank cleaned.

Engineer Comments -

The G/Ss D3,4,&5 were not tested as they were not used by the 3 phones on display. I later discovered another phone under the counter that did use these G/Ss and the G/S D3 seemed to work OK but I did not test D4 or D5.

The very bright fluorescent light behind the rack makes it difficult to see the front of the equipment. I would suggest moving this light in front of the equipment and just having a small light behind for maintenance purposes.


Maintenance
2012-10-02

Work carried out by D. Williams

1) F/S C6 (1st choice F/S) - Basic maintenance ? adjusted wipers and oiled mechanism
2) F/S D2 (2nd choice F/S) - Basic maintenance ? adjusted wipers, oiled mechanism and cleaned bank
3) 1st G/S D1 - Basic maintenance ? adjusted wipers, cleaned banks and oiled mechanism
4) 1st G/S C3 - Basic maintenance ? adjusted wipers, cleaned banks and oiled mechanism
5) 1st G/S C1 ? Cleaned U-points, bank, wipers, relay contacts, cleaned oiled and adjusted mechanism as required
6) 1st G/S C2 ? Cleaned U-points, bank, wipers, relay contacts, cleaned oiled and adjusted mechanism as required
7) 1st G/S C4 ? Cleaned U-points, bank, wipers, relay contacts, cleaned oiled and adjusted mechanism as required
8) 1st G/S C5 ? Cleaned U-points, bank, wipers, relay contacts, cleaned oiled and adjusted mechanism as required
9) 1st G/S D2 ? Cleaned U-points, bank, wipers, relay contacts, cleaned oiled and adjusted mechanism as required
10) 1st G/S D3 ? Cleaned U-points, bank, wipers, relay contacts, cleaned oiled and adjusted mechanism as required
11) 1st G/S D4 ? Cleaned U-points, bank, wipers, relay contacts, cleaned oiled and adjusted mechanism as required
12) 1st G/S D5 ? Cleaned U-points, bank, wipers, relay contacts, cleaned oiled and adjusted mechanism as required
13) I/C G/S C10 ? Cleaned U-points, bank, wipers, relay contacts, cleaned oiled and adjusted mechanism as required
14) 1st C2 O/G JCT R/S Cleaned U-points, and relay contacts
15) Installed cabling from PABX3 to UAX13 for level 9 access to the UAX13 and DDI access to the PABX 3
16) I/C G/S C10 ? Modified the H wire battery from 250 ohms to ~150ohms with a 300ohm resistor in parallel
17) The 2 spare 2000 type G/Ss E7 & E8(not in service) had shafts that had siezed up ? these are now released.


General Maintenance
2013-10-21

Maintenance work carried out by David Williams 17/09/2013 - 23/09/2013

1) Fault - 1st D2 Heat coil blown - repaired
2) Fault - 1st D4 Heat coil blown - repaired
3) Fault - 1st E4 hunt fail - FT adjustment screw loose - relay readjusted
4) Fault - FS1 C6 no restore - heat coil dirty - cleaned
5) Fault - 1st D shelf no dial tone - No red link in D5 broke start chain
6) 1st selector rack - no heat coil alarm - rewired
7) 1st selector rack - no fuse alarm - rewired
8) All covers cleaned
9) Clock power feed rewired
10) 1st D1-5 and E1-5 cleaned adjusted and LEDs added
11) Ringer control panel installed
12) F/S C1-5 graded in, cleaned, adjusted, and LEDs added
13) F/S C5 A relay coil changed
14) F/S D8 B relay coil open circuit - awaiting new 1300 ohm relay coil
15) 1st D6 and D7 are tested spare group selectors if required
16) 1ST G/S D7-9 and E7-10 are untested and should not be used
17) F/S C6 & C7 are tested spare final selectors if required
18) F/S D6-8 and E1-8 are untested and should not be used
19) Old grading cable removed and all old contacts cleaned up
20) Pulse generator not running when group selector seized - rewired & overhauled
21) Filled all empty equipment positions and cleaned covers
22) Strapped subs IDF so all lines ending in 8 are spare (NU tone) and all other lines are in service
23) 1ST C3 O/G JCT R/S - Wired onto LEV 8 and connected on the bn/w wires across to the UAX13
24) Rear covers installed - One cover missing from 1st A shelf and on the F/S rack 2 covers are too long


Routine Maintenance
2014-04-27

Ringing machines

Tested all spare ringers plus one new one and labelled them with their status
2 working on rack
2 working spare
3 faulty

All 1st selectors

FT relay adjusted and tested (should resolve L/F hunting problem)

Final Selectors

C4 & C5 banks cleaned

Trimphone installed

Maintenance carried out by D. Williams


2017 Exchange Maintenance Visit - David
2017-04-16

PABX3 1st AD5 under-stepping vertically – detent sticking – oiled and adjusted 1st AD53 under stepping vertically – detent sticking – oiled and adjusted 1st AE5 shaft sticking – oiled and adjusted 1st AE1 under-stepping vertically – detent sticking – oiled and adjusted 1st AE3 under-stepping vertically – detent sticking – oiled and adjusted 1st AE2 no vertical stepping – fuse loose in linefinder Re-configured the O/G junctions so that there are now 2 junctions, both on level 9 Air blasted all banks No release or fuse alarms on G/S rack - rewired alarm wiring to lamps

Related Objects
PABX3 Telephone Exchange - Generate printable document for all related objects

PABX3 Telephone Exchange

PABX3 Ringing Machine

PABX3 Ringing Machine

PABX3 Ringing Machine

PABX3 Ringing Machine

PABX3 Ringing Machine

AT5422 Tester

PABX3 Pulse Distribution Relayset

PABX3 Faultsman Ringback Relayset

PABX3 Manual Alarms Relayset

PABX3 Route Discriminator Relayset

PABX3 Route Discriminator Relayset

PABX3 Route Discriminator Relayset

PABX3 Route Discriminator Relayset

PABX3 Route Discriminator Relayset

PABX3 Ringing Common Relayset

PABX3 Ringing Control Relayset

PABX3 Ringing Control Relayset

PABX3 Outgoing E & M Relayset

PABX3 Outgoing E & M Relayset

PABX3 Exchange Line Relayset

PABX3 Exchange Line Relayset

PABX3 DDI Jct Relayset

PABX3 Final Selector

PABX3 Final Selector

PABX3 Final Selector

PABX3 Final Selector

PABX3 Final Selector

PABX3 Final Selector

PABX3 Final Selector

PABX3 Final Selector

PABX3 Final Selector

PABX3 Final Selector

PABX3 Final Selector

PABX3 Final Selector

PABX3 Final Selector

PABX3 Final Selector

PABX3 Final Selector

PABX3 Final Selector

PABX3 Group Selector

PABX3 Group Selector

PABX3 Group Selector

PABX3 Group Selector

PABX3 Group Selector

PABX3 Group Selector

PABX3 Group Selector

PABX3 Group Selector

PABX3 Group Selector

PABX3 Group Selector

PABX3 Group Selector

PABX3 Group Selector

PABX3 Group Selector

PABX3 Group Selector

PABX3 Group Selector

PABX3 Group Selector

PABX3 Group Selector

PABX3 Group Selector

PABX3 Group Selector

PABX3 MDF

AT5422 Tester