TELEPHONE No. 6500


HAZARDOUS AREA TELEPHONE
TELE 6500 AR

 

SAFETY
The Hazardous Area Telephone (HAT) is available for use in industrial sites which by their very nature may be potentially hazardous. Installers must not work in hazard areas unless the area has been made safe for the duration of the working time.
HAT must be securely isolated, in a safe area (by removing fuses or operating lockable isolation switch if provided) from line and from any extension calling devices (n.b. these may be Mains powered) before any work is carried out inside HAT, or on the associated cabling.

DESCRIPTION
HAT, as supplied by BT, is a hard-wired, weather-resistant, water resistant (to I line powered, dual signalling press button telephone certified for use in certain explosive atmospheres'. It is for wall or table mounted use and offers the following facilities:-
LD or MF signalling (not switchable to MF during a call)
Earth or Timed Break recall *
Adjustable tone caller volume (high off low)
Last number redial (21 digits max)
Microphone mute (S button on keypad)
Reed-switch gravity switch (operated by magnet in handset)
Handset microphone inset used as tone caller

There is no PBX access pause with the Last Number Redial facility, when used on PBXs requiring access pause, the access digit may be keyed manually and the remaining digits sent by pressing the 'LR' button.
* Set by non user-accessible switches inside the telephone (which must be isolated before opening, see SAFETY).

Made by DAC Ltd
Shobnall Street, Burton upon Trent, Staffordshire DE14 2HD
Telephone 0283 500500

APPROVAL STATUS
Approved under approval number S/1363/3/J/453189 for PST or hard wired connection to the network or to extensions of PBXs in categories 1 - 12 inclusive. N.B any PST connections must be in a defined safe area.

BASEEFA (British Approvals Service for Electrical Equipment in Flammable Atmospheres) Approved

Modifications which have not received BABT and BASEEFA approval must not be carried out as to do so would invalidate approval making connection to the network unlawful.

PLANNING
REN, HAT has a REN of 1 provided the internal ring detect relay is not used and may be (3-wire) connected with other HAT on the same circuit (within the limitations of REN). But should be 2-wire connected (i.e. without the 'Bell' wire to LJU 3) if used with other types of telephones (N.B HAT may then cause bell tinkle on other instruments whilst dialling out).

Although HAT is approved for 3-wire connection to PST arrangements, this is not recommended due to on-hook power requirements of HAT. The shunt effect of any parallel connected instrument or extension bell is likely to prevent the HAT from operating.

HAT effectively has a REN of 2 If approved extension bells or lamps (available separately) are to be connected via HAT internal ring detect relay, i.e. no more than 2 HAT's should be connected for correct operation of the relay.

HAT is also designed to work from -20' C to +45' C, has protection against ingress of moisture to IP 65 and is line powered requiring no additional power supply.

BASEEFA Certification. HAT is primarily intended for use in Zones 1 & 2 of hazardous areas as defined in BS 5345 (i.e. where there are 'explosion risks due to the presence of flammable gases or vapours').

Hazard Zones in BS 5345 are defined as follows :-
Zone 0 In which an explosive gas-air mixture is continuously present or present for long periods.
Zone 1 In which an explosive gas-air mixture is likely to occur in normal operation.
Zone 2 : In which an explosive gas-air mixture is not likely to occur in normal operation, and if it occurs will only exist for a short time.

The cabling to the telephone, where it passes through Zones 1 or 2 must comply with BS 5345 parts 6 & 1.
HAT (or associated cabling) is not certified for and must not be installed in Zone 0 or in areas where there are combustible dusts.

NB It is the customer's responsibility to define the types of hazards and Zones where they may be present, details of these must be obtained from, and cable routing and equipment siting must be agreed with customer's site safety representative or other authorised person before any work is started.

INSTALLATION/COMMISSIONING
HAT must be installed in accordance with the installation instructions supplied with the instrument. The signalling, recall and tone ringer loudness switches are inside the telephone and must be set on installation.
n.b. The LD/MF signalling switch must never be left in the mid position.

The telephone must be isolated from line before the telephone case is opened in the hazard areas (see 'Safety').

Cable terminations are as shown below, the cable entry holes in the case are threaded to accept standard 20mm conduit fittings or glands. Where conduit is used, the ends must be sealed with 'Mixture No. 2' to prevent any entry of gas from the conduit.

After installation and before commissioning HAT should be inspected as per section 3 of BS 5345 : Part 6 and cabling should be inspected as per initial inspection in Table 4 of BS 5345 : Part 1.

It is important that connection of the HAT base moulding to conduit, MI or armoured cable gland is carried out by competent persons eg approved electrical contractors.

Where the HAT base moulding is fitted separately to the rest of the telephone the following precautions must be taken to retain warranty and BASEEFA certification :-
i. The base moulding must be suitably protected whilst it is open and the sealing lip must be free of any damage.
ii. The telephone 'top half' and line termination circuit board must be suitably protected whilst separated from the 'base moulding'.
iii. The insulating washers must be placed on the middle pair of support pillars to prevent termination board tracks short circuiting on the pillars.

A Leg (5)
B Leg (2)
Recall(4)
Earth
Connection arrangements for HAT (and extension HATS)

n.b. * A wire link must be fitted between terminals S2 & C3 on first or single HAT only, to connect the ringer circuit capacitor.

HAT has a conductive case which must be earthed by connection to metal conduit, metal sheath of mineral insulated cable or by use of approved metal gland to sheath of armoured cable. The threads of conduit bushes/ cable glands where they couple up to the threaded cable entry holes in the instrument case must be sealed to prevent ingress of explosive vapours, they must also make good metallic contact with the case of the instrument to maintain earth continuity, if this is not possible then the HAT earth bonding kit (available extra) must be used.

Suitable approved extension calling devices (bells, lamps, hooters etc) should be connected to HAT. The relay contact switching limits are 250VAC at 5 Amps or 30V DC at 5 Amps, the 'Live' supply must be connected to the 'Ring detector contact'.
Calling device wiring must be kept away from telephone cabling, HAT must be isolated from Line and external power before HAT case is opened (See SAFETY).

MAINTENANCE
Maintenance of HAT is restricted to functional testing, visual inspection of case and cable entry seal integrity, checking the signalling, recall and tone ringer switch settings are correct or instrument changeout. There are no field replaceable parts and if the instrument appears faulty must be replaced. To avoid disturbing conduit, MI or armoured cable glands on HAT's where there is no damage to the base moulding, the base moulding may be left in place and just the 'top-half' and line termination board replaced, the faulty instrument must be re-assembled with the back moulding of the replacement HAT for return under warranty or repair.
n.b. The precautions listed under Installation must be taken.

The telephone must be isolated from line before the telephone case is opened in the hazard areas (see 'Safety').

ROUTINE MAINTENANCE
HAT and associated cabling is subject to the Periodic inspections, Testing and Maintenance requirements of BS 5345: Part 1, HAT is also subject to the Inspection, Maintenance and Testing section of BS 5345: Part 6. These recommend inspections at no greater than two yearly intervals and tests at no greater than three yearly intervals.
N.B. Testing should be carried out in consultation with the customers site safety representative (or other authorised person).

HANDLING PRECAUTIONS
Care must be taken not to damage telephone case or cable entry seals or internal components whilst working inside HAT. When table mounted, the lower case moulding is wedge shaped and may be turned round to give. a convenient working angle, it is important to turn this in a clockwise direction so that the internal linking cable stows neatly.
When wall mounting HAT , care must be taken not to strain the linking cable which joins the two halves of the instrument case.


	 PARTS
         Description				BT Item Code
	 HAT                                    87 7885
         HAT Wall mounting bracket              87 7886
         Mixture No2                            07 1638
         earth bonding kit          Manufacturer's code 100-02-0039-001
         (available direct  from DAC Ltd)

         

Fixing Screws:- For direct mounting - Pan-head screws max dia 6.5mm (max head dia 12mm) length 15mm plus depth of wall penetration (4 required). For use with wall bracket - Any suitable screws/bolts up to 1OMM dia.

N.B. Screws or other fixings must be weather/ corrosion resistant and suitable for use in the particular environment.

Cable Glands
(when single wire armoured or braided cable used) - Any suitable type approved by BASEEFA to 'EX e', they must be the correct size for the cable sheath diameter and fitted by competent persons.

TOOLS/TESTERS/CARRYING CASES
Normal hand tools including Screwdriver Instrument No.1 (for cable terminations), Screwdriver Cabinet 5" (for direct wall mounting), Hexagonal Wrenches ('Allen' Keys) of the following sizes:-
5mm (e.g. Wrench Ball ended 5mm Item Code 14 1761) to open the telephone.
10mm (local purchase) to remove additional conduit entry plug (if required).
2.5mm (local purchase) to remove internal earth bonding plate (it required).

Tools as necessary to connect conduit bushes/ cable glands to cable entry in telephone case (for use by competent persons only).

Site approved insulation and earth-loop impedance testers.

N.B. All Tools and test equipment are subject to approval by customers site safety representative or other responsible person.

LINE TESTING
Idle - Normal capacitor loop, additionally HAT draws on-hook current (typically 21 ma) to maintain stored/last number memory. This may give apparent 'Low Loop' line test conditions.

Seized - Normal press button telephone loop. The electronic keypad and transmission circuitry may give 'high resistance' tele-loop line test conditions as with other press button telephones.

ADDITIONAL INFORMATION
HAT may be used as direct replacements for existing Flameproof telephones. When used to replace these instruments, cabling through zones 1 & 2 must be checked and if necessary modified so that it conforms to BS 5345 Part 1. This may require re-cabling in conduit through hazard areas. After any changes or alterations, the complete system should be inspected as per Installation/Commissioning.
A local record must be kept of inspections and test results.

The Tone caller volume switch should normally be left in the loud position on installation unless the customer requests otherwise (the 'quiet' position is very quiet). Customer requests for louder or extension bells should be referred to sales for consideration of approved additional bells/ lamp signalling systems.
Signalling details;
MF tone applied for as long as keypad button pressed, with a minimum tone burst 100 milli Seconds.
Earth recall is via a solid state switch which will only operate when correct line conditions are present, hence HAT is not suitable for use as an Earth calling, power fail terminal' on earth calling PBXS.

 
 
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Last revised: May 30, 2010

FM