AUTELDAC 3

AUTELDAC 3 

HAZARDOUS AREA TELEPHONE 

Operating and Technical Manual 

Document Ref: 502-MN-0026 Issue 6 / June 2002

PAGE 1 

AUTELDAC 3 

HAZARDOUS AREA TELEPHONE 

AUTELDAC 3 - CURLY CORD VERSION 

TYPE 212-02-0005-001 

AUTELDAC 3 - STAINLESS STEEL CORD VERSION 

TYPE 212 02-0005-002 

CONFIDENTIAL 

The contents of this publication are confidential and are the property of GAI-Tronics and 

may not be reproduced, wholly or in part, without their written permission. 

POLICY 

The policy of GAI-Tronics is one of continual development and improvement of products 

and we reserve the right therefore to alter specifications without notice. 

GAI-Tronics Ltd 

Brunel Drive 

Stretton Park 

BURTON-UPON-TRENT 

Staffordshire 

England 

DE13 0BZ 

Tel. : +44 (0)1283 500500 

Fax.: +44 (0)1283 500400 

COPY NO.__________ 

Controlled/Uncontrolled 

Registered holders of Controlled copies will automatically 

receive revisions and reissues as they are produced - see within 

Auteldac 3, Hazardous Area Telephone, 


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IMPORTANT NOTICE 

This manual is devoted to the AUTELDAC 3 HAZARDOUS AREA TELEPHONE 

The AUTELDAC 520 is developed directly from the AUTELDAC 3 and differs ONLY in the 

following criteria: 

1. Case is moulded in light grey glass filled polyester DMC. 

2. External labels referenced to BASEEFA are omitted. 

Type Nos are: 

AUTELDAC 520 COILED CORD 024-02-1020-001 

AUTELDAC 520 STAINLESS STEEL CORD 024-02-1020-002 

SPECIAL NOTE ON SAFETY REQUIREMENTS 

The enclosure, cable glands and cables must meet the requirements of IP54, or better, in 

order to satisfy 'Increased Safety' ('e'-type) requirements. 

Only 'e'-type glands and suitable cables should be used and must be fitted correctly in 

order to maintain IP54. The enclosure lid, cables and cable glands must NOT be removed 

unless ALL supplies to the telephone - i.e., in-coming telephone wires and the supply for 

an external ringer - have been isolated OUTSIDE the hazardous area. Terminals for 

incoming cables are 'e'-type and should be carefully used to make an 'e'-type cable 

termination. 

The Code of Practice for 'e'-type enclosures is BS 5345 Parts 1 and 6. 

The user should be familiar with the relevant sections of these documents. 



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TECHNICAL PUBLICATION REVISION SERVICE 

As product developments and modifications occur from time to time revisions to this 

publication will be produced and will be sent automatically to registered holders of 

Controlled copies. 

If you want to be registered, please complete the Registration Form below by either, 

photocopying it or cutting it out, and returning it to GAI-Tronics, Technical Publications. 

Also strike out the word "Uncontrolled" on the title page of this publication. 

If you do not want to be registered, please strike out the word "Controlled" on the title 

page of this publication (for the advice of other users). 

REVISION SERVICE REGISTRATION FORM 

USE BLOCK CAPITALS PLEASE 

Title of Publication 

Tech. Pub. Number (bottom of title page) 

Copy No. (from the title page) 

Name of holder 

Job title 

Full address to which revisions should be sent :- 

Complete and return to : 

GAI-Tronics Ltd 

Technical Publications 

Brunel Drive 

Stretton Park 

BURTON-UPON-TRENT 

Staffordshire 

England 

DE13 0BZ 



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502-MN-0026 Issue 6 / June 2002

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REVISION RECORD 

This is a blank sample of the Revision Record Sheet which will accompany each revision 

package and which will list details of the contents of the package. 

Please retain these Record Sheets with the up-dated copy of the publication in order to 

maintain control of its status. 

Date Issue No. Details of Revision 



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CONTENTS 

TECHNICAL PUBLICATION REVISION SERVICE...................................................3 

REVISION RECORD .................................................................................................4 

CONTENTS ...............................................................................................................5 

ILLUSTRATIONS.......................................................................................................8 

1.0. TECHNICAL AND APPLICATION DATA...........................................................9 

1.1. General Description ...............................................................................9 

1.2. Performance Data..................................................................................11 

1.3. Physical Data .........................................................................................12 

1.3.1. Enclosure Materials.................................................................12 

1.3.2. Overall Dimensions: ................................................................12 

1.3.3. Weight .....................................................................................13 

1.4. Standards, Regulations, approvals ........................................................14 

1.4.1. Standards and Regulations.....................................................14 

1.4.2. Approvals ................................................................................15 

1.5. Drawings and Documents......................................................................15 

2.0. HANDLING, TRANSPORT AND STORAGE.....................................................16 

2.1. Handling.................................................................................................16 

2.2. Transportation........................................................................................16 

2.3. Storage ..................................................................................................16 

3.0. INSTALLATION INSTRUCTIONS .....................................................................17 

3.1. Installation..............................................................................................17 

3.1.1. Preparation..............................................................................17 

3.1.2. LD or MF dialling .....................................................................18 

3.1.3. TB or ETH recall......................................................................18 

3.1.4. Ringer loudness ......................................................................18 

3.1.5. Cable entries ...........................................................................18 



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3.1.6. Direct or Bracketed wall mounting ..........................................18 

3.1.7. Earth Bonding Stud (optional) .................................................19 

3.2. Reassembly ...........................................................................................20 

3.2.1. Wall mounting .........................................................................20 

3.2.2. Desk-top operation..................................................................20 

3.3. Wall Mounting ........................................................................................20 

3.3.1. Direct wall mounting................................................................20 

3.3 2. Bracketed wall mounting .........................................................21 

3.3.3. Cabling ....................................................................................21 

4.0. OPERATING INSTRUCTIONS..........................................................................26 

4.1. Operation ...............................................................................................26 

4.1.1. Incoming Call ..........................................................................26 

4.1.2. Outgoing Call ..........................................................................26 

4.1.3. Microphone Muting..................................................................27 

4.1.4. Exchange Recall .....................................................................27 

4.1.5. Last Number Redial ................................................................27 

5.0. MAINTENANCE IN THE WORKING ENVIRONMENT......................................28 

5.1. Technical Description.............................................................................28 

5.1.1. Introduction .............................................................................28 

5.2. Terminal Board ......................................................................................29 

5.2.1. On-hook quiescent condition...................................................29 

5.2.2. Received Ring Current............................................................30 

5.2.3. Installation of Encapsulated Fuse Assembly...........................30 

5.2.4. Handset Off-hook ....................................................................32 

5.2.5. Loop Disconnect (LD) dialling .................................................33 

5.2.6. Dual Tone Multi-frequency (MF) dialling .................................33 

5.2.7. Earth Recall.............................................................................33 

5.3. I.S. Board ...............................................................................................33 

5.3.1. On-hook quiescent condition...................................................33 

5.3.2. Received Ring.........................................................................35 

5.3.3. Handset Off Hook....................................................................35 

5.3.4. Dialling ....................................................................................36 

5.3.5. Conversation ...........................................................................37 

5.3.6. Recall ......................................................................................37 

5.3.7. Last Number Redial (LR) ........................................................38 

5.3.8. Line Length Compensation .....................................................38 



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5.4. Keypad Board ........................................................................................38 

5.4.1. Keypad Connections ...............................................................38 

6.0. SERVICING AND REPAIR ................................................................................40 

6.1. Servicing ................................................................................................41 

6.2. Repair ....................................................................................................42 

6.2.1. Terminal Board replacement...................................................42 

6.2.2. I.S. Board replacement ...........................................................42 

6.2.3. Keypad Board replacement.....................................................43 

6.2.4. Handset replacement ..............................................................43 

6.2.5. Hookswitch (Switchboard Relay) Board replacement .............45 

APPENDICES............................................................................................................47 

CONTENTS ...................................................................................................47 

APPENDIX A .............................................................................................................49 

REPLACEABLE PARTS ................................................................................49 

APPENDIX B .............................................................................................................51 

COPY OF BASEEFA CERTIFICATES OF APPROVAL ................................51 



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ILLUSTRATIONS 

Fig 1.1. - Auteldac 3 / Auteldac 5 General View........................................................ 9 

Fig 1.2. - Overall and Fixing Dimensions................................................................... 13 

Fig 1.3. - Internal Layout............................................................................................ 14 

Fig 3.1. - PCB Switches............................................................................................. 17 

Fig 3.2. - Earth Bonding Kit........................................................................................ 19 

Fig 3.3. - Cable Plans - Part 1 ................................................................................... 24 

Fig 3.4. - Cable Plans - Part 2 ................................................................................... 25 

Fig 4.1. - Front Panel Layout - Armoured Cord ......................................................... 26 

Fig 5.1. - Internal Layout with Paxolin Protection Removed ...................................... 28 

Fig 5.2 - Terminal Board Simplified Block Diagram ................................................... 29 

Fig 5.3. - Refitting the Earthing Plate......................................................................... 31 

Fig 5.4. - Connection the Terminal Blocks................................................................. 32 

Fig 5.5. - I.S. Board Simplified Block Diagram........................................................... 34 

Fig 5.6. - Keypad Board Circuit.................................................................................. 39 

Fig 6.1. - Handset Cord Assembly............................................................................. 44 

Fig 6.2. - Layout Details............................................................................................. 44 



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1.0. TECHNICAL AND APPLICATION DATA 

Fig 1.1. - Auteldac 3 / Auteldac 5 General View 

1.1. GENERAL DESCRIPTION 

• The Auteldac 3 telephone combines the latest technology with 

traditional safety features. 

• Certified for use in Zones 1 and 2 Group IIC T5 (T amb =50 o C) 

Hazardous Areas, as defined in: 

• EN50.014 

EN50.019 

EN50.020 

EN50.028 

• The telephone is rugged and weatherproof (to IP66). 

• Auteldac 3's dual-purpose design allows wall mounting or desk-top 

use. It is fully electronic and is internally switchable for LD or MF 

dialling and its recall facility is also switchable for Timed Break or 

Earth recall systems. 



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• Speech quality conforms to BS 6317 Class A standard. 

• The telephone features Last Number Redial and a Silence button 

(microphone mute switch) and has a built-in ring detector contact, 

rated at 250V 5A 300W, for switching an external mains-powered 

audible device or beacon. 

• Its own ring tone is a penetrating shrill warble (78 dBA @ 1m) 

typical. 

• It can operate in temperatures of -20 o C to +50 o C. 

• Auteldac 3 is compatible with Class A and Class B impedances, as 

defined in BS6305, and is therefore suitable for use with any 

approved PABX or PMBX. It is available with either a conventional 

curly handset cord or a heavy-duty stainless steel spiral cord. 

• Lines to the telephone would normally be SWA or wire-braided 

types. 

NOTE 

• Auteldac 3 is approved by the Office of Telecommunications 

(OFTEL), under Approval No. S/1363/3/J/453189, for connection to 

a Public Switched Telephone Network (PSTN) or a Private Branch 

Exchange (PBX), either via a line jack plug or a tool connection 

A Line Jack Plug connection in a hazardous area would NOT be 

approvable to BASEEFA requirements. 


The enclosure, cable glands and cables must meet the requirements of 

IP54, or better, in order to satisfy 'Increased Safety' ('e'-type) 

requirements. 

Only 'e'-type glands and suitable cables should be used and must be 

fitted correctly in order to maintain IP54. The enclosure lid, cables and 

cable glands must NOT be removed unless ALL supplies to the telephone 

- i.e., in-coming telephone wires and the supply for an external 

ringer - have been isolated OUTSIDE the hazardous area. Terminals for 

incoming cables are 'e'-type and should be carefully used to make an 

'e'-type cable termination. 


The user should be familiar with the relevant sections of these 

documents. 



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1.2. PERFORMANCE DATA 

Speech: 

Ringing Tone: 

Transmission to BS 6317:1982, part 13, Class A 

Impedance Class A and B (BS 6305:1982) 

Shrill warble tone (2.0 kHz to 2.8 kHz, 8 Hz 

sweep rate) 

The tone output level is switchable: 

Full volume: 78 dBA @ 1 metre typical 

Reduced volume: 68 dBA @ 1 metre typical 

Off: 

Zero 

NOTE 

REN (Ringer Equiv. No.): 1 (one) 

For reliable ring detector performance, no more than two telephones 

may be connected in parallel 

In-built Secondary ) Contact Rating, AC: 250V @ 5A 

Ringer Unit ) DC: 30V @ 5A 

(External Audio/Visual ) (Single contact) 

device controller, RLA) ) 

Hook Switch: 

Dialling system: 

Reed switch, mounted internally on pcb. 

Operated magnetically through casing 

LD and MF (switchable) 

Dialling Data: 

LD: to BS 6305:1982, part 4.4.2 

Impulse rate: 

10 ips 

Break/Make Ratio: 2:1 

MF: to BS 6305:1982, part 4.4.3 

MF Impedance: Class A and B 

MF transient voltage: Class A 

Dialling tones meet international standards requirements 

NOTE 

Recall Button: 

Switchable for Earth Recall and Timed Break Recall 

TBR duration is between 53 and 103 milliseconds) 

Relative Humidity: 

Operating Temperature: 

Power Supply: 

up to 95% (non-condensing) 

-20 o C to +50 o C 

Drawn from telephone line 



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1.3. PHYSICAL DATA 

See 

Fig 1.2. - Overall and Fixing dimensions 

Fig 1.3. - Internal Layout 

1.3.1. ENCLOSURE MATERIALS 

Enclosure Material: 

Surface Resistivity: 

Degree of Protection: 

Handset Material: 

Handset Inserts: 

Dial: 

Handset Cord: 

Carbon-fibre loaded glass-filled polyester SMC 

10 9 ohms maximum 

IP66 

Polycarbonate 

Sealed to IP66 

Weather sealed tactile digital keypad 

Curly cord or stainless steel spiral cord 

(specified when ordering) 

1.3.2. OVERALL DIMENSIONS: 

a. Configured for direct wall mounting: 

Width: 

Height: 

Depth: 

181 mm approx. 



Fixing Centres: 

(four M6 pan head or cap screws) 

Horizontal spacing: 145 mm 

Vertical spacing: 270 mm 

b. Configured for bracketed wall mounting: 

Width: 

Height: 

Depth: 




Fixing Centres: 

(four M10 bolts or screws and washers) 

Horizontal spacing: 211 mm 

Vertical spacing: 270 mm 



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c. Configured for desk-top operation: 

Width: 

Height: 

Depth: 




1.3.3. WEIGHT 

(Standing on four pvc feet) 

Weight: 

3.1 Kg approx. 

Fig 1.2. - Overall and Fixing Dimensions 



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Fig 1.3. - Internal Layout 

1.4. STANDARDS, REGULATIONS, APPROVALS 

1.4.1. STANDARDS AND REGULATIONS 

Health and Safety at Work Act, 1974 

BS 6317 : 1982 

BS 6305 : 1982 

BS 6301 

BS 5501 

(Telephone Performance) 

(Telephone Performance) 

(Telecom Safety) 

(Hazardous Gas Safety) 

parts 1, 6, 7 and 8 



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PAGE 15 

EN50.014 

EN50.019 

EN50.020 

EN50.028 

BSEN60529 : 1992 

BS 5750 : 1979 

BS 5345 

BS 5490 : 1977 

(General) 

'e' 

'i' 

'm' 

(Ingress Protection) 

(Quality Systems) 

(Selection, Installation and Maintenance of 

parts 1 and 6 Equipment) 

(Sealing Specification) 

1.4.2. APPROVALS 

NOTE: 

BASEEFA Certification No. : Ex 88Y2311 

Ex 92C2415 

Approved type : EEx e m ib IIC T5 (T amb = 50 o C) 

A copy of the BASEEFA Certificate of Assurance is at Appendix B. 

OFTEL Approval No. : 

S/1363/3/J/453189 

1.5. DRAWINGS AND DOCUMENTS 

Unit Assembly Drawings GAI-Tronics Drawing Number 

Auteldac 3 Hazardous Area 

Weatherproof Telephone 212-03-0005 sheets 1 and 2 

PCB Assembly Drawings 

Terminal Board 999-03-0481 

I. S. Board 999-03-0482 

Keypad Board 999-03-0450 

Handset Assembly Drawings 

Steel Cord and 

Curly Cord versions 032-03-0016 



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2.0. HANDLING, TRANSPORT AND STORAGE 

2.1. HANDLING 

The compact and robust nature of the construction of the Auteldac 3 

Hazardous Area Weatherproof Telephone, together with a maximum 

unit weight of about 3.1 kg, means that there is no need for special 

handling techniques, especially if the unit is kept in its delivery carton 

when not in use. 

2.2. TRANSPORTATION 

For overland transportation, the Auteldac 3 telephone should remain in 

its delivery carton and it is necessary only to ensure that it cannot slide 

or bounce during transit. 

If the delivery carton has been mislaid, it would be advisable to wrap the 

unit in sacking, corrugated cardboard, or similar material, to avoid the 

risk of scratching the body work. 

2.3. STORAGE 

For long-term storage purposes, it is recommended that the units are 

sealed into plastic bags containing silica-gel crystals. 

Ambient temperature should be maintained below 60 o C. 

If the units are unprotected, they should be stored in as dust-free, 

corrosion-free, and dry an atmosphere as possible. Ensure that the 

gland entry blanking plugs, where fitted, are firmly in place and that 

unplugged holes are securely taped over. 



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3.0. INSTALLATION INSTRUCTIONS 

3.1. INSTALLATION 

3.1.1. PREPARATION 

IMPORTANT 

Prior to installation, the telephone must be configured for - 

1. Loop Disconnect (LD) or Dual Tone Multi-frequency (MF) dialling 

2. Timed Break (TB) or Earth (ETH) recall 

3. Ringer loudness 

4. Cable entries 

5. Direct or Bracketed wall mounting 

6. Earth Bonding Stud (optional) 

METHOD 

1. Release the telephone base by slackening incrementally, in turn, the 

four captive M6 cap head socket screws, recessed one at each 

corner on the front of the telephone body (5mm hex socket driver 

required). 

2. Remove the body from the base, noting that complete separation is 

prevented by a cable linking the body and the base. It is not 

necessary to disconnect the cable for installation purposes, but 

should this be desired it is more easily disconnected from the base 

end than from the body end. 

3. Lay the body of the telephone face down and see Fig 3.1 to identify 

the configuring switches. 

Fig 3.1. - PCB Switches 

In the following, interpret 'left' and 'right' as illustrated in Fig 3.1. 



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3.1.2. LD OR MF DIALLING 

1. Move the Dialling selector switch firmly to the left for LD dialling. 

2. Move it firmly to the right for MF dialling. 

NEVER leave this switch in the centre 'off' position. 

3.1.3. TB OR ETH RECALL 

1. Move the Recall selector switch firmly to the left for TB recall. 

2. Move it firmly to the right for ETH recall. 

If the Recall facility is not required, the switch can remain in the centre 

'off' position. 

3.1.4. RINGER LOUDNESS 

1. Move the Tone Ringer loudness selector switch firmly to the right for 

maximum Ringer volume. 

2. Move it firmly to the left for reduced volume. 

To mute the Ringer, leave the switch in the centre 'off' position. 

3.1.5. CABLE ENTRIES 

One or two 20mm Ex 'e' Cable Glands, as required, suitable for the 

selected cable, may be installed at this time, or later, immediately prior 

to cabling the telephone. 

Two cable entry holes are provided in the bottom wall of the telephone 

base, one of which is closed off with a blanking plug. 

If only one entry is required, fit a 20mm Ex'e' Cable Gland in the open 

hole, leaving the blanking plug in situ. If two entries are required 

(connection to a parallel telephone or a Remote Ringer or Beacon), 

remove the blanking plug and fit a second 20mm Ex 'e' Cable Gland. 

3.1.6. DIRECT OR BRACKETED WALL MOUNTING 

For either type of wall mounting: 

1. Remove the four p-v-c feet which are a push fit into the telephone 

base. 

Direct wall mounting: 

2. No further preparation required. 



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Bracketed wall mounting: 

Use GAI-Tronics Mounting Kit type 100-02-0040-001. 

3. Position the two brackets horizontally across the back of the 

telephone base. 

4. Secure with the four M6 x 20mm cap-head socket screws and spring 

washers supplied. (5mm hex driver required). 

NOTE: 

5. Tighten firmly. 

The mounting holes in the bracket are M10 clearance, with 211mm 

horizontal separation between centres and, when fitted, 270mm vertical. 

3.1.7. EARTH BONDING STUD (OPTIONAL) 

See Figure 3.2. - Earth Bonding Kit 

Use GAI-Tronics Earth Bonding Stud Kit type 100-02-0039-001. 

1. Remove the securing screws of the internal earth bonding plate from 

the telephone base. 

NOTE: 

2. Fit the earth bonding block and other items supplied in the kit. 

The number of spacer washers required varies according to the size of 

the earth cable used. For cables up to 2mm diameter, use three spacer 

washers; for 2mm to 4mm diameter, use two washers; for 4mm to 6mm 

diameter, use one washer. 

Fig 3.2. - Earth Bonding Kit 



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3.2. REASSEMBLY 

The base and body of the telephone may be reassembled in either of 

two orientations - 

1. Wall Mounting 

2. Desk-top operation 

3.2.1. WALL MOUNTING 

The two parts go back together with the cable entry holes at the bottom 

of the telephone when visualised in a vertical position. 

3.2.2. DESK-TOP OPERATION 

NOTE : 

Only the Curly Cord version, type 212-02-0005-001, is recommended for 

Desk-top operation, owing to the shorter length of the Stainless Steel 

cord. 

1. Rotate the body of the telephone "clockwise" through 180 o so that 

the cable entry holes are at the rear of the telephone when it is lying 

flat in its desk- or table-top position. 

NOTE 

Anticlockwise rotation would make stowage of the linking cable 

difficult. 

In both cases: 

2. Offer the telephone body into position on the base. 

3. Ensure that the gasket is correctly seated. 

4. Lightly tighten the four holding screws. 

5. Send the telephone to its installation site. 

3.3. WALL MOUNTING 

3.3.1. DIRECT WALL MOUNTING 

Separate the body and the base of the telephone, as described in para. 

3.1., Preparation. 



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NOTE: 

1. Mount the telephone base onto a flat vertical surface with the cable 

entries at the bottom, using the four M6-clearance holes provided. 

Screw length should be 15mm plus the wall penetration depth required 

and the maximum screw-head diameter must be 12mm. No sealing 

washers are required. DO NOT use counter-sunk screws. 

If telephone cables are not to be connected immediately: 

2. Replace the telephone body on the base. 

3. Seat the gasket correctly. 

4. Lightly tighten the four captive holding screws. 

5. Seal the gland entry. 

3.3 2. BRACKETED WALL MOUNTING 

With brackets fitted as described in para 3.1. Preparation: 

1. Secure the telephone onto a flat vertical surface with the cable 

entries at the bottom, using four M10 bolts, or screws, and washers. 

3.3.3. CABLING 

IMPORTANT 

IMPORTANT 

ISOLATE MAINS POWER AT REMOTE POINT BEFORE 

INSTALLATION OR MAINTENANCE 

For adequate operation of the internal Tone Ringer, up to four 

telephones may be connected in parallel, i.e. the REN value of the 

Auteldac 3 telephone is 1. 

However, for adequate operation of the in-built ring detector to drive a 

Remote Ringer or Beacon, no more than two telephones may be 

paralleled. If more than two are paralleled, their respective Tone Ringers 

will operate but the detector contacts will not. 

See Fig 3.3. - Cable Plans - Part 1 and Fig 3.4. - Cable Plan - Part 2. 



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Recommended cable sizes: 

Flexible cable: 0.5 - 2.5 mm 2 

Solid cable: 0.5 - 4.0 mm 2 

See 

'SPECIAL NOTE on SAFETY REQUIREMENTS' 

on page 1 of this Handbook 

IMPORTANT 

Various features of the design and construction of this equipment are 

essential to the maintenance of BASEEFA Certification requirements for 

operation in hazardous areas. Unauthorised changes of values or layout 

will invalidate certification 

METHOD 

1. Separate the body and base of the telephone, as described in 

para.3.1. Preparation. 

NOTE: 

IMPORTANT 

2. When cabling to a wall-mounted telephone, to avoid the body 

dangling on the linking cable, it can be offset to the left and 

temporarily supported on the telephone base by lightly fixing the 

right-hand pair of retaining screws into the left-hand pair of threaded 

inserts. 

No damage will result if the body is left suspended, but it is not 

recommended. 

At the time of connection to the telephone, the line must be totally 

isolated from the Telephone Exchange and must be entirely 

voltage free. 

3. Make up the cable-core ends as required for connection to the 

terminal blocks in the telephone base. 

4. Dismantle the outer parts of the 20mm Ex 'e' Cable Gland(s) and 

thread them onto the cable(s) in the correct order. 

5. Feed the cable end(s) into the telephone through the gland body (or 

bodies) and reassemble the outer gland parts. Before tightening the 

gland assembly, check that there is sufficient, but not too much, 

slack in the cable inside the telephone. 



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PAGE 23 

6. Connect cable cores to terminals as illustrated in Figs 3.3 and 3.4, 

noting that, if a Remote Ringer or Beacon is fitted, the RING DET 

contact must be made to switch the 'live' side of the mains supply 

(Fig 3.3, b and d). 

7. Run the line to the Telephone Exchange 

8. Connect to the desired extension terminals at the MDF. 

IMPORTANT 

For adequate operation of the internal Tone Ringer, up to four 

telephones may be connected in parallel, i.e. the REN value of the 

Auteldac 3 telephone is 1. 

However, for adequate operation of the in-built ring detector to drive a 

Remote Ringer or Beacon, no more than two telephones may be 

paralleled. If more than two are paralleled, their respective Tone Ringers 

will operate but the detector contacts will not. 



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PAGE 24 

IMPORTANT 



Fig 3.3. - Cable Plans - Part 1 



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PAGE 25 

IMPORTANT 



Fig 3.4. - Cable Plans - Part 2 



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4.0. OPERATING INSTRUCTIONS 

4.1. OPERATION 

Fig 4.1. - Front Panel Layout - Armoured Cord 

4.1.1. INCOMING CALL 

When the telephone rings: 

1. Pick up the receiver. 

2. Speak into the microphone. 

3. Listen at the earpiece. 

4.1.2. OUTGOING CALL 


2. Listen at the earpiece for the Exchange dial tone. 

3. Press the digits of the required number. 

4. Wait to hear the Exchange ringing out, or the 'busy' or 'unobtainable' 

tone. 



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4.1.3. MICROPHONE MUTING 

During conversation, in loud ambient noise conditions, to prevent 

background noise being transmitted to the far end: 

1. Hold the 'S' button pressed when listening - release when speaking. 

4.1.4. EXCHANGE RECALL 

If your local Exchange is suitably equipped: 

1. Recall by momentarily pressing the 'R' button. 

4.1.5. LAST NUMBER REDIAL 

To redial the last number dialled: 

1. Replace the receiver. 


3. Listen for the Exchange dial tone. 

4. Momentarily press the 'LR' button. 

5. Wait to hear the Exchange ringing out, or the 'busy' or 'unobtainable' 

tone. 

NOTE 

For successful 'redial', the number must be one of "not more than" 21 

digits. 



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5.0. MAINTENANCE IN THE WORKING ENVIRONMENT 

5.1. TECHNICAL DESCRIPTION 

5.1.1. INTRODUCTION 

Fig 5.1. - Internal Layout with Paxolin Protection Removed 

IMPORTANT 

Various features of the design and construction of this equipment are 

essential to the maintenance of BASEEFA Certification requirements for 

operation in hazardous areas. Unauthorised changes of values or layout 

will invalidate certification 

"See 'SPECIAL NOTE on SAFETY REQUIREMENTS' on page 2 of 

this Handbook." 



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5.2. TERMINAL BOARD 

Fig 5.2 - Terminal Board Simplified Block Diagram 

5.2.1. ON-HOOK QUIESCENT CONDITION 

With an Exchange line connected to the B (negative) and A (positive) 

terminals (and, optionally, the E (earth) terminal) and a link between the 

C and S terminals, the Terminal Board presents two bridge rectifier 

circuits and a high-resistance d.c. path to the Exchange, as follows :- 

a. For the detection of Ring current from the Exchange, the path is 

from the B terminal via capacitor C3, the C to S terminals link and 

the bridge rectifier D4-D7, to the A terminal. 



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The 'Ring pulses' output from the rectifier connects to a Ring Tone 

generator on the I.S. Board through SK1 pins 1 (positive) and 2 

(negative), via the coil of relay RLA and a 100 mA HRC fuse. 

b. To provide the d.c. loop for dialling and speech, the path is from 

the B terminal via the switched bridge rectifier consisting of D2, D3, 

G2, G3, D5 and D7, and the I.S. Board circuitry, to the A terminal. 

The output of this rectifier (when switched on) energises the 

dialling and speech circuits on the I.S. Board, again via SK1 pins 

1(+) and 2(-). 

c. Whenever the rectifier in item b. is switched off, depriving the I.S. 

Board of power, a very small current (about 20 micro-amps) flows 

through resistor R10 and rectifier D4-D7 into the I.S. Board to 

maintain the last-number-dialled memory in its Dialler i.c. 

The lines between this board and the I.S. Board are protected by Zener 

diodes and current limiter resistors in order to establish the 

requirements of BASEEFA certification and all the circuitry on this board 

is 'potted' to maintain its integrity. 

While the handset is on-hook, the semi-conductor gates, G1 to G5, all 

remain in an 'open' (high impedance) condition so that the Exchange 

line is not looped and the telephone awaits the arrival of Ring current. 

5.2.2. RECEIVED RING CURRENT 

When Exchange Ring current is received, it is rectified by D4-D7 and 

delivered to the I.S. Board to sound the Ring Tone generator, at the 

same time energising relay RLA (because G4 is open) to control a 

remote Ringer or Beacon, if fitted. 

This action follows the pulses of Ring current as they are received from 

the Exchange and will continue for as long as the Exchange is ringing 

out and the handset remains on hook. 

5.2.3. INSTALLATION OF ENCAPSULATED FUSE ASSEMBLY 

IMPORTANT 

A 2 amp 'e' type fuse may be fitted into the Auteldac 3 and connected in 

series with the remote ringer contacts to protect the contacts against 

inadvertent connection of mains supply directly to the ringing terminals. 

Disconnect telephone from line and mains input before commencing any 

dismantling. 



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PAGE 31 

METHOD 

1. Remove back plate from telephone enclosure 

2. Disconnect mains input wires from the terminal block on the main 

PCB and the earth wire from the earthing plate connection. 

3. Remove the screws, nuts and washers securing the clamping plate 

to the enclosure and retain ensuring that the nuts and washers are 

kept with their respective screw. 

4. Refit the earthing plate, using the shortest screw positioned in the 

uppermost hole (see Fig 5.3), ensuring that the nylon sealing 

washer is on the outside of the enclosure. 

Fig 5.3. - Refitting the Earthing Plate 

5. Remove the short piece of wire from the fuse terminal block, bare 

the end and connect it to terminal 2 of the PCB terminal block (see 

Fig 5.4). 

6. Attach the fuse assembly bracket to the earthing plate at the lower 

hole using the long screw previously retained. Replace nuts and 

washers ensuring that the nylon sealing washer is on the outside of 

the enclosure (see Fig 5.4). 

7. Connect wire from terminal 2 of the PCB terminal block to Terminal 

3 of the Fuse assembly terminal block. 

8. Connect mains input wires to the PCB terminal block and the fuse 

assembly terminal block )(see Fig 5.4). 



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Fig 5.4. - Connection the Terminal Blocks 

9. Connect the earth wire to the long screw holding the fuse assembly 

bracket., 

10. Replace the back plate ensuring all seals are intact and in good 

condition. 

NOTE 

When replacing a fuse, first remove the short screw through the earthing 

plate. This will allow the fuse to be withdrawn rearwards after releasing 

the appropriate screws in the fuse assembly terminal block. 

5.2.4. HANDSET OFF-HOOK 

When the telephone handset is taken off-hook, either in response to 

incoming rings or in order to dial out, pin 4 of SK1 on the Terminal Board 

is driven high by an output from the I.S. Board (described in para.5.3.1). 



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This high is inverted by INV1 to close G1 which, in turn, closes G2 and 

G3 to activate the d.c. loop rectifier - described in para 5.2.1. b, above - 

which causes the Exchange to be looped through the I.S. Board and so 

either stop ringing out (and establish a speech circuit), or start to 

transmit a dial tone. 

INV1 output also closes G4, which shorts out the coil of relay RLA. 

These conditions remain as described for as long as the handset is off 

hook, except while Loop Disconnect (LD) dialling is in progress. 

5.2.5. LOOP DISCONNECT (LD) DIALLING 

When a dial tone is being received from the Exchange and the user 

commences to dial out with the 'LD' dialling mode selected, each 

successive dial pulse from the I.S. Board causes SK1 pin 4 on the 

Terminal Board to be taken low for about 67 msec, causing a break in 

the Exchange loop by momentarily opening the semi-conductor gates, 

G1 to G4. 

5.2.6. DUAL TONE MULTI-FREQUENCY (MF) DIALLING 

If the MF dialling mode is selected, SK1 pin 4 remains high throughout 

the dialling process, the Exchange loop remains intact and the loop 

current is modulated by the MF tone frequencies on the I.S. Board - 

similar to normal speech transmission. (See para.5.3., I.S. Board). 

5.2.7. EARTH RECALL 

If the 'Earth Recall' facility is selected, then pressing the 'R' button on 

the keypad when the handset is off hook will cause SK1 pin 3 on the 

Terminal Board to go high for as long as the button is held pressed, 

closing semi-conductor gate, G5, for that period, connecting the 

Exchange B-wire through D3 and G2 to the earth at terminal E. 

5.3. I.S. BOARD 

See Fig 5.5. - I.S. Board Simplified Block Diagram 

5.3.1. ON-HOOK QUIESCENT CONDITION 

About 20 micro amps of line current flows into the Keypad Dialler circuit 

via the resistor across TR5, to maintain the last-number-dialled memory 

in IC2 (as described in para 5.2.1.c.). 



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PAGE 34 

Fig 5.5. - I.S. Board Simplified Block Diagram 

TR6 is 'on' (low impedance) to connect the positive line voltage (at SK1 

pin 4) to the Ring Tone Generator - but the negative line to the 

Generator is disconnected by a semiconductor switch in its input. 

All other TR devices are 'off', so the Speech circuit is not energised at 

this time and the Keypad Dialler circuit outputs are all low, keeping the 

switched rectifier bridge on the Terminal Board in the 'off' condition (see 

para 5.2.1.c.). 



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5.3.2. RECEIVED RING 

Received ring current, rectified on the Terminal Board (see para 5.2.1), 

results in a rise in the positive voltage applied through TR6 to the input 

of the Ring Tone Generator. 

This activates the semiconductor switch referred to in para 5.3.1. to 

connect the negative return line to the Generator, causing it to output 

the tone to the handset microphone - which is isolated by TR1 and acts 

as a loudspeaker for this function. 

An on-board Loudness switch, SW6, allows quieting, or complete 

muting, of the tone, as required. 

This action follows the pulses of Exchange ring current until the handset 

is taken off hook. 

5.3.3. HANDSET OFF HOOK 

Taking the handset off hook (whether in response to an incoming ring or 

in order to dial out) causes the hookswitch contact to close, putting the 

positive voltage at SK1 pin 4 into the 'gate' of TR6 and into the HSW 

input of the Keypad Dialler circuit. 

TR6 is turned off by this, stopping the Ring Tone Generator. The 

response of the Dialler i.c. to the HSW input is to drive its MASK output 

high, turning on TR3 which, in turn, turns on TR2 and TR5. 

The MASK output is also delivered to the Terminal Board, via SK1 pin 1, 

where it turns on the switched bridge rectifier, as described in 

para 5.2.1. c. 

When TR2 conducts, it energises the Speech circuit and completes a 

d.c. loop on the Exchange line between SK1 pins 4 and 2, via the 

Speech circuit. If the Exchange has been ringing out, this loop causes it 

to stop ringing and to establish a speech circuit; if it was not ringing, the 

loop causes it to output its dial tone. 

The voltage applied to the Speech circuit also turns on TR1 to connect 

the handset microphone to its input. 

When TR5 conducts (the symbol indicates its function as a current 

generator), it applies increased power for normal operation of the 

Keypad Dialler circuit. 

The circuit is now ready for dialling (if dial tone is being received) or 

conversation (if answering an incoming ring). 



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5.3.4. DIALLING 

Two types of dialling facility are available, depending upon the 

requirement of the associated Exchange and selected by an on-board 

switch, SW5. 

Both types retain the last number dialled (up to 21 digits) in a memory 

store for later single-button re-dialling, if required. 

a. Dual Tone Multi-frequency (MF) 

As the digits of the required number are inserted at the Keypad, 

they are put into an intermediate store in IC2, then transmitted as 

discrete tone pairs at the correct rate and duration. This is the MF 

TONES output. 

They are applied to an amplifier in IC1 whose output modulates the 

loop current flowing through it, so transmitting them to the 

Exchange. (The MASK output from the Dialler i.c. remains high 

throughout MF dialling to keep the switched bridge rectifier on the 

Terminal Board in the 'on' condition). 

Throughout tone transmission from IC2, its MUTE output is held 

high, which disables the microphone and quietens the earphone 

amplifiers in the Speech circuit (IC1). 

b. Loop Disconnect (LD) 

As the digits of the required number are inserted at the Keypad, 

they are put into an intermediate store in IC2. 

As the first digit button is pressed, the MASK output goes low, but 

the IMP (impulsing) output goes high. MASK going low turns off 

TR3 which, in turn, turns off TR2 to break the d.c. loop through the 

Speech circuit. But at the same time, IMP going high turns on TR4 

to maintain the loop through the Zener diode, ZD5 - and also keep 

TR5 conducting. 

Additionally, the IMP output, via SK1 pin 1, maintains the switched 

bridge rectifier on the Terminal Board in the on condition. 

The dialling pulses appear as negative-going excursions of the IMP 

output, causing breaks in the d.c. loop through ZD5 and the gates 

on the Terminal pcb, having the required break/make ratio and 

interdigit pauses. 



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PAGE 37 

At the end of dialling, IMP goes low and MASK goes high, restoring 

the loop through the Speech circuit to allow the Exchange 

response to be heard and subsequent conversation to be enabled. 

The MUTE output remains low throughout LD operation. 

5.3.5. CONVERSATION 

Speech into the handset microphone is pre-amplified, then delivered to 

the same amplifier in IC1 as are the tones during MF dialling. 

The speech frequencies similarly modulate the loop current for 

transmission to the Exchange. 

A sample of the speech waveform is also mixed with an antiphase 

version of itself, in the correct amplitude ratio to provide a comfortable 

level of side-tone in the handset earpiece. 

Received speech is developed across a small resistor in the loop and is 

amplified in IC1, with gain control from TR7/TR8, to deliver a good 

listening level at the handset earpiece. 

Reverse-connected diodes across the earpiece lines protect the ear 

against acoustic shock. 

At any time during a conversation, the keypad 'S' button can be held 

pressed to mute the handset microphone and prevent background noise 

or speech being transmitted to the distant user. 

5.3.6. RECALL 

Exchange Recall, if applicable, is achieved by pressing the 'R' button on 

the keypad. It is available in either of two forms, selected by an on-board 

switch, SW4. 

a. Timed Break Recall (TBR) 

When MF dialling is being used, pressing 'R' causes the MASK 

output of the Dialler circuit to go low for 100 milliseconds, so 

breaking the Exchange loop for that period. 

When LD dialling is being used, pressing 'R' causes a single dial 

pulse to be output from IMP of the Dialler circuit, so breaking the 

Exchange loop for about 67 milliseconds. 



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b. Earth Recall (ETH) 

In either dialling mode, pressing 'R' causes a high (+) potential to 

be output via SK1 pin 2 to G5 on the Terminal Board. G5 conducts 

to connect the system earth (from customer terminal TB1) to the 

negative wire from the Exchange, for as long as the button is held 

pressed. 

5.3.7. LAST NUMBER REDIAL (LR) 

When the handset is replaced on hook, the digits of the last number 

dialled are retained in memory in the Dialler i.c. (provided that the 

number comprises 21 digits or less). 

This stored number may be redialled by going off hook and pressing the 

keypad 'LR' button once. 

5.3.8. LINE LENGTH COMPENSATION 

The safety requirements of: 

a) maintaining a low surface temperature on all unpotted components 

on the I.S. Board 

b) maintaining the required voltage level on the speech circuits, 

are satisfied by the operation of the duplicated circuit including 

TR7/TR8, TR9/TR10 and associated components. 

For increasing values of line current exceeding a certain threshold, 

TR7/TR8 turn on TR9/TR10 to progressively lower values of source-todrain 

resistance in order to shunt the excess current away from the I.S. 

Board components. 

Under these conditions, which reflect the effective length of the 

telephone line, the progressively increasing potential at the collectors of 

TR7/TR8 is used as a compensating gain control on the transmit and 

receive speech amplifiers in IC1. 

5.4. KEYPAD BOARD 

See Fig 5.6. - Keypad Board Circuit 

5.4.1. KEYPAD CONNECTIONS 

The keypad on Auteldac 3 has the usual twelve digit and Exchange 

function buttons (digits 0 to 9, hash and star) plus three control buttons 

('R' : Recall; 'S' : Silence - microphone mute; 'LR' : Last number Re-dial). 



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PAGE 39 

The miniature microswitches operated by these buttons connect into the 

I.S. Board by a 13-way plug and socket, SK2 - part of which is shown on 

the Simplified Block Diagram. (The two pins shown, SK2/12 and 

SK2/13, connect between IC1, pins 11 and 10, and the 'S' button on the 

keypad). 

The full listing of the SK2 pin connections between the Dialler i.c., the 

Speech i.c., the TBR/ETH switch, SW4, and the keypad is as follows :- 

IC2 / IC1 SK2 KEYPAD 

IC2 pin 15 pin 1 column 3 



IC2 pin 16 & SW4 pin 4 row 1 

IC2 pin 17 pin 5 row 2 



IC2 pin 20 & SW4 pin 8 Redial button (LR) 

IC2 pin 17 pin 9 Redial button (LR) 

SW4 pin 10 Recall button (R) 

SW4 pin 11 Recall button (R) 

IC1 pin 11 pin 12 Mic Mute button (S) 

IC1 pin 10 pin 13 Mic Mute button (S) 

Fig 5.6. - Keypad Board Circuit 



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PAGE 40 

6.0. SERVICING AND REPAIR 

See Fig 5.1. - Internal Layout with Paxolin Protection Removed 

NOTE 

It is essential that maintenance personnel are familiar with the 

relevant portions of BS 5345 : Part 1 : 1976 and Part 6 : 1977. 

Particularly note the extract reproduced at the bottom of page 31 of this 

Handbook and "see 'SPECIAL NOTE on SAFETY REQUIREMENTS' 

below." 


The enclosure, cable glands and cables must meet the requirements of 

IP54, or better, in order to satisfy 'Increased Safety' ('e'-type) 

requirements. 

Only 'e'-type glands and suitable cables should be used and must be 

fitted correctly in order to maintain IP54. The enclosure lid, cables and 

cable glands must NOT be removed unless ALL supplies to the telephone 

- i.e., in-coming telephone wires and the supply for an external 

ringer - have been isolated OUTSIDE the hazardous area. Terminals for 

incoming cables are 'e'-type and should be carefully used so as to make 

an 'e'-type cable termination. 


The user should be familiar with the relevant sections of these 

documents. 

WARNING 

NUMEROUS COMPONENTS IN THE AUTELDAC 3 TELEPHONE 

ARE SENSITIVE TO ELECTROSTATIC 

DISCHARGE AND MAY BE IRREPARABLY DAMAGED IF THE 

STANDARD HANDLING PRECAUTIONS 

FOR SUCH DEVICES ARE NOT STRICTLY OBSERVED. 

THE UNIT SHOULD ONLY BE OPENED BY QUALIFIED AND 

EXPERIENCED PERSONNEL. 



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PAGE 41 

6.1. SERVICING 

In view of the stringency of BASEEFA Certification requirements, it is 

recommended that customer repair is limited to printed circuit board or 

handset replacement and that, for component-level repairs, a faulty unit 

should be returned to GAI-Tronics. 

All repair work must be carried out under workshop conditions and must 

not be attempted in hazardous areas. 

By the removal of four recessed, captive holding screws, the telephone 

may be separated into front and back halves, the body and base 

respectively, interconnected by a four-core cable with plug and socket 

connections at each end. 

The telephone circuitry is accommodated on four printed circuit boards 

(PCBs), as follows: 

a. A Terminal board, GAI-Tronics type 999-02-0481-001, which also 

supports the customer terminal blocks and is mounted in the 

telephone base. 

b. An I.S. board, GAI-Tronics type 999-02-0482-001, which supports 

most of the electronics and is mounted in the telephone body. 

c. A Keypad board, GAI-Tronics type 999-02-0450-001, which 

supports miniature micro-switches activated by push-buttons and is 

also mounted in the telephone body. 

d. A Hookswitch (Switchboard Relay) board, GAI-Tronics type 999- 

02-0454, which is in the telephone body adjacent to the handset 

position, and which mounts a single magnetic reed switch which 

acts as a telephone hookswitch. 

Additionally, a blank, paxolin board covers and protects the I.S. board 

from accidental contact (which may damage electrostatic-sensitive 

components). 

The interconnecting cable between body and base is sufficiently long to 

allow the two halves to lie side by side on a workbench. To completely 

separate the two, unplug the cable and release the P-clip at the 

Terminal Board in the telephone base. 



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6.2. REPAIR 

6.2.1. TERMINAL BOARD REPLACEMENT 

1. Separate the two halves of the unit, as described in para 5.2.1. 

2. Unplug the 4-pin connector on the Terminal Board in the telephone 

base. 

3. Remove the Terminal Board by the removal of six M4 button head 

socket screws and washers. 

4. Install a replacement board and reassemble the unit in the reverse 

order. 

6.2.2. I.S. BOARD REPLACEMENT 

1. Separate the two halves of the unit, as described in para.5.2.1. 

2. Unplug the 4-pin connector on the I.S. Board in the telephone 

body. 

3. Release the interconnecting cable from its 'P-clip' by the removal of 

the M3 button head socket screw and washers securing the clip. 

(Retain the clip, screw and washers). 

4. Release the I.S. Board by releasing the four M4 button head 

socket screws which are accessible through holes in the bakelite 

protective plate. The screws must be released incrementally in turn 

and will remain captive between the PCB and the plate. 

5. Carefully lift the I.S. Board part-way out of the body. 

6. Unplug the two connectors at the side and top of the board. (A 2- 

pin from the hookswitch; a 13-pin from the Keypad Board). 

7. Release the four handset wires from the screw-terminal block near 

the top of the board, taking note of the wire insulation colours for 

later reference. 

8. Install a replacement I.S. Board and Protection Plate assembly and 

reassemble the unit in the reverse order. 



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PAGE 43 

6.2.3. KEYPAD BOARD REPLACEMENT 

1. Proceed as item 5.2.2.(b) for the removal of the I.S. Board, but 

without the need to disconnect the interconnecting cable or the 

handset wires. 

2. Lay the I.S. Board to one side and remove the Keypad Board by 

the removal of six M4 button head screws and washers and two 

hexagonal pillars. 

3. Lift the Keypad Board out of the telephone body. 

4. Peel the buttons membrane off its front surface. 

5. Lay the buttons membrane back in the telephone body so that the 

switch housings are central in their front panel holes. 

6. Install a replacement Keypad Board. 

7. Reassemble the unit in the reverse order. 

6.2.4. HANDSET REPLACEMENT 


without the need to disconnect the interconnecting cable. 

2. Release the four handset wires from the screw-terminal block near 

the top of the I.S. Board, taking note of the wire insulation colours 

for later reference. 

3. Lay the I.S. Board to one side and release the handset cord anchor 

by the removal of two M4 button head socket screws and washers 

securing a steel plate at the top right corner of the Keypad Board. 

4. Refer to Fig 6.1. - Handset Cord Assembly, for the correct order of 

dismantling and reassembly. 

5. Install a replacement Handset. 




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502-MN-0026 Issue 6 / June 2002

PAGE 44 

Fig 6.1. - Handset Cord Assembly 

Fig 6.2. - Layout Details 



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502-MN-0026 Issue 6 / June 2002

PAGE 45 

6.2.5. HOOKSWITCH (SWITCHBOARD RELAY) BOARD REPLACEMENT 


without the need to disconnect the interconnecting cable or the 

handset wires. 

2. Lay the I.S. Board to one side and remove the Hookswitch Board 

(to the left of the Keypad Board) by the removal of two pan head 

slotted self-tapping screws. 

3. Install a replacement Hookswitch Board. 


EXTRACT FROM BS 5345 : PART 1 :1976 

29. Isolation of Apparatus 

For apparatus protected other than by type of protection 'i' and for noninductive 

apparatus (for which guidance is given in Parts 4 and 7 

respectively), no apparatus should be opened in a hazardous area until 

it has been disconnected from its source of supply and effective 

measures, such as the locking of the isolating switch in the open 

position or fuse removal, have been taken to prevent its being made 

alive before re-assembly. Particular attention should be paid in the case 

of an apparatus that may be live even after it has been disconnected 

from the source of supply. Where heavy rotating machinery is involved, 

the back e.m.f. of such plant should be considered and precautions will 

usually need to be taken to ensure that the apparatus, or any apparatus 

associated with it, is not opened until the rotating plant is stationary. 

Most power capacitors are fitted with discharge resistors and it should 

be noted that these take a finite time to bring the terminal voltage to a 

harmless value. 

Where for purposes of electrical testing it is essential to restore the 

supply before the apparatus is re-assembled, special dispensation 

should be authorised by the issue of a gas free certificate. 



45 

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PAGE 46 



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502-MN-0026 Issue 6 / June 2002

PAGE 47 

APPENDICES 

CONTENTS 

APPENDIX A 

APPENDIX B 

REPLACEABLE PARTS 

COPY OF BASEEFA CERTIFICATES OF 

APPROVAL 



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PAGE 48

PAGE 49 

APPENDIX A 

REPLACEABLE PARTS 

STORES NAME OF GAI-TRONICS 

IDENT. NO. PART COMPONENTS VOCAB. NO. 

Line Connect PCB/ 

Termination PCB 999-02-0481-001 

Earth Plate Internal *, Ex 501-12-0920-001 

Blanking Plug Exe, *, Ex, IP 604-09-0007-000 

Keypad Membrane *, Ex, IP 501-40-0157-001 

Keypad PCB Assembly 999-02-0450-001 

Lid Screws *, Ex (per 10) 501-99-0294-001 

Hand Stowage 501-55-0006-001 

Handset Assembly, 460 mm SS Cord(STD) 100-02-0031-005 

Handset Assembly, 1 metre SS Cord 100-02-0031-003 

Handset Assembly, 1.5 metre SS Cord 100-02-0031-002 

Handset Assembly, 2 metre SS Cord 100-02-0031-004 

SS Cord Sealing Assembly *, Ex, IP 100-02-0047-001 

Handset Assembly, 1 metre CCord (STD) 100-02-0032-005 

Handset Assembly, 1.5 metre Curly Cord 100-02-0032-002 

Handset Assembly, 3 metre Curly Cord 100-02-0032-003 

Handset Assembly, 5 metre Curly Cord 100-02-0032-004 

Curly Cord Sealing Assembly *, Ex, IP 100-02-0046-001 

Fuse for Fuse Kit (if fitted) (per 10) 299-12-0002-001 

Rubber Feet (per 10) 610-03-0039-000 

IMPORTANT 

The use and fitments of items from this spares list is not recommended without reference 

to the service manual as in many cases the correct procedure is necessary to achieve 

sealing or location to maintain the BASEEFA, sealing and/or Telecoms approved status. 

The items where special attention is required are annotated with * an Ex, IP or BT for 

BASEEFA, sealing or Telecoms approvals respectively.

PAGE 50

PAGE 51 

APPENDIX B 

COPY OF BASEEFA CERTIFICATES OF APPROVAL 

1. CERTIFICATE OF ASSURANCE Ex 88Y2311 

2. CERTIFICATE OF CONFORMITY Ex 92C2415

PAGE 52

PAGE 53

PAGE 54

PAGE 55

PAGE 56

AUTELDAC 3

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