APPROVAL No. S/1249/3/J/453305

User Guide

Sales Brochure - PHME4960

The BT Renown is a self contained switching system with one exchange line port and up to 4 extensions. Extension instruments may be any BS6317 approved telephone instruments (MF or LD signalling) with an earth recall button and/or Renown systemphones (in any combination).

The system is through-fed on Exchange Line calls hence extension telephones must be configured for MF or LD signalling according to the type of signalling supported by the line/host system.

System Facilities include:-

  • Internal and external calls.

  • Hold, Enquiry & Transfer.

  • Conference.

  • Call Shuttle.

  • Switchable call barring (outgoing access denied except extension 1).

Renown Systemphones are for table or wall mounted use and give LED indication of line status, 10 number memory, last number redial and mute. It is not essential to have Systemphones on Renown.

The CCU is completely self contained and includes a plug ended cord for connection to the network via a Master Line Jack Unit.

Connection of the extension wiring is via Insulation Displacement Connectors (IDC's) housed within the CCU. The system is powered from a 13 amp mains socket outlet via a plug top transformer.

Mark 2 versions of CCU and Systemphones were introduced in 1992, these supersede and are externally similar to the original models. The Mark 2 CCU incorporates minor changes to improve RFI immunity and ringer output, the Mark 2 Systemphone incorporates minor internal changes.

Made by Philips Ltd

Approved DEL plus PBX CAT 1, 3, 5, 7, 9 & 11.
Approved for plug in connection to the PSTN or host PBX extension. Renown is approved for DIY installation and is not subject to pre-connection inspection and approved maintainer requirements.

Renown is not approved for Off-Site external extensions that go back out via the Network.

Maximum CCU to extension cabling length is limited to 25 ohms (approx. 150 cable metres) for a Systemphone and 50 ohms (approx. 300 cable metres) for a standard telephone complying with BS6317, using cable equipment 6 wire 2503F. Extensions with Systemphones use five conductors of the extension cable extensions with BS 6317 telephones use 3 conductors of the extension cabling.

There is no provision for standby power, the exchange line is connected through to extension 1 under power fail conditions.

Due to the length of the line cord and transformer lead, Renown must be sited not more than 2 metres from a LJU or Linebox (NTE5) and a 240 Volt, 13 Amp, mains socket outlet.
The Renown CCU has a REN of 4. Due to limitations of the Renown ringing generator, each extension port effectively has an output REN of 2. Contrary to normal practice, any additional sockets on Renown extensions will need to be Master Jacks to optimise ringer output. Only one Systemphone may be connected per extension circuit.

Renown is not intended to be used as a 4 port intercom system as extension 1 will remain dead until the exchange line is powered up.

Technical information
These notes are applicable to Renown systems installed in the UK and connected to telecommunications systems run by British Telecommunications plc, Kingston Communications (Hull) plc or Mercury Communications Ltd.

1. The Renown system is suitable for use on Exchange/PBX lines which provide facilities for either Loop Disconnect (LD) or TouchTone* (MF) dialling. It can be used with either Earth Loop Recall (ELR) or Timed Break Recall (TBR).

2. The Renown system is designed to operate with a mains supply of 240V, 50Hz.

3. The Renown system is not suitable as an extension to a payphone.

4. Approval for the connection of extension instruments by the Department of Trade and Industry is only granted provided that the distance between the Renown control unit and the extension socket does not exceed 150m if connecting a Renown Systemphone, or 300m if connecting a standard telephone.

5. The control unit to Renown Systemphone line loop resistance (speech pair only) is 25 ohms maximum; the control unit to standard telephone line loop resistance (speech pair only) is 50 ohms maximum.

6. Only telephones approved to BS6317 (1982) shall be connected to the Renown system. The telephone must have the Earth Loop Recall facility.

7. The Renown is suitable for connection in subsidiary mode to most PBXS. However, satisfactory performance cannot be guaranteed with every allowable combination of host and subsidiary system.

Further information on the installation of telephone systems can be referred to in the British Standard Code of Practice, BS6701 Parts 1 and 2.

The Renown control unit and extension telephones should be installed and operated in an environment within the following specific limitations

Temperature range:
Operating - 5'C to 45'C
Storage - 20'C to 60'C

Relative humidity: <95%

Renown should be installed and commissioned in accordance with the installation instructions supplied with the CCU and also contained within the Product Manual. The Exchange line cord must be plugged into a working line (or PBX extension) and the line voltage switch set to the appropriate voltage for the CCU to initialise (otherwise extension 1 will remain 'dead'). A wired-in functional earth is not required. Where Renown is connected to the extension of an earth recall PBX, the recall earth is provided via LJU4 terminal of the CCU line cord.

Mains power must be turned off whilst any switch settings are changed as the CCU only responds to the settings on power-up.

Underneath each Renown telephone is an exchange switch.  This must be set to correspond with the dialling type expected by the local exchange.  Set to MF (tone dialling) or LD (pulse dialling)

Control Unit Switches
To the lower right of the control unit there is a bank of five switches.  The table below explains the actions of each switch.

Switch number OFF (down) ON (up)
1 25 volt exchange line 50 volt exchange line
2 Time Break Recall Earth loop Recall
3 Extn 2 Outgoing calls Allowed Extn 2 Outgoing calls Barred
4 Extn 3 Outgoing calls Allowed Extn 3 Outgoing Calls Barred
5 Extn 4 Outgoing calls Allowed Extn 4 Outgoing Calls Barred

Uses Line jack units -/1A

System Colour Socket
1 GREEN/White 1
2 BLUE/White 2
3 ORANGE/White 3
4 WHITE/Orange 4
5 WHITE/Blue 5
6 WHITE/Green 6

Renown contains its own 1.8uf ringing capacitor and detects ringing from the MLJU / NTES terminals 2 & 5. When tested from the serving exchange, the Renown capacitor is connected in parallel with the capacitor in the MLJU / NTES and will therefore measure about twice the normal capacitance.

w units for initial supply or for use as maintenance spares carry a 24 month warranty from the date of manufacture as shown by the first 4 digits (YY WW) the 11 digit serial number on the underside of the unit. Customers purchasing Renown from BT are given a 12 month guarantee from the date of purchase, irrespective of the date of manufacture.


Renown CCU (Complete transformer and line cord) 870373
Renown Mk2 CCU (Complete transformer and line cord) 870514
Renown Systemphone 870374
Renown Systemphone Mk2 870515
Renown CCU (Refurbished) 941655
Renown Systemphone (Refurbished)   943307

Extension telephones - Not all modern telephones with an earth recall button will work on Renown, CFN BT 2+8 & Renown 003 gives inter-working details.

Line Voltage switch (SW1) settings - Renown monitors the voltage across the exchange line to determine whether the line is free, as below:-
(SW1, set to 50v) - Line voltage less than 36 Volts = 'Exchange Line busy'.
(SW1, set to 24v) - Line voltage less than 18 Volts = 'Exchange Line busy'.
There are some circumstances where the exchange line voltage can vary in service over these thresholds (e.g. some local line concentrator systems or WB 900 carrier systems) resulting in the exchange line appearing to be busy when in fact it is free. Where this occurs on systems with SW1 set to 50v it may be overcome by trying SW1 set to 24v (CCU must be powered down during switch changes).

Renown on lines with WB 1400 equipment connected WB1400 has line charged batteries which can cause line voltage to drop below 18 Volts causing similar problems to the above, in this case altering the SW1 position may not be effective. The official advice is for BT to notify the appropriate local authority that the WB1400 must be removed from the line.

Systemphones connected via answering machines etc - Certain answering machines (BT Wren & Kingfisher II) incorporate a socket for the associated telephone as these also only have 4 way line cords, systemphones should be plugged into the normal line jack via a doubler and not into the answering machine otherwise the 'data pair' will be interrupted resulting in Systemphone function.

Intercom Circuits - Renown has only one intercom circuit, whilst this is being used for hold & enquiry/transfer purposes it will not be available for extension to extension calls (and vice versa).

Extension ringer limitations - Due to limited ringing voltage output, no more than two ringing devices (telephones or extension bells) should be connected at any extension, Converter Ringers No.15 are not suitable for use on Renown and should not be offered.

Power Supply
Renown comes with a power block that plugs straight into the mains.  The lead from the power block is a standard telephone cord and connects to the system board via a Molex connector marked PLB.

The Power Block is a Power Supply 3513 456 02250 and has an output of 15.4 volts AC at 2.4ma (0.35va) & 30.2 volts AC at 250ma (7.55va).

Molex & Cord Wiring

Molex PLB Power Cord Voltage
5 Green 30 vac
4 White 15 vac
3 Blue 30 vac
2 -
1 Red 15 vac



Briefly, intended enquiry calls have resulted in calls going into conferencing mode. It is thought that this could be due to a digit 5, in MF, being received by the Renown Systemphones from a nearby instrument signalling handsfree.

This issue, previously detailed earlier, is still ongoing. Escalation to the manufacturer has resulted in Philips requesting customers sites to visit. Please ensure that it is only the Systemphones that are affecting transmission.

Several reports have been received stating that intended enquiry calls have resulted in calls going into conference. This could cause embarrassment to customers as they rightly expect the enquiry call to be with secrecy from the exchange line.

The facility for conference can be invoked by dialling '5' (in LD or MF) whilst the E/L is on hold and the internal (xtn-xtn) call is in progress. It has been demonstrated that if equipment nearby (1-2m) is dialling out in handsfree/monitor mode, the Renown Systemphone can detect a digit '5' in the digit string and therefore switch into conference mode.

Enhanced versions are now available of the Converse 200, Relate 200 and Vanguard 10E with pre-programmed network service keys for Call Waiting, Call Diversion, Charge Advice and Reminder Call. Any of the keys offering a non-required facility can be overwritten with an alternative network service code or used as a memory store for any PSTN number.

Use of each of these items is. however, restricted if connected to extension ports of Renown, 2+8 or 2+8E systems. These limitations are as follows:

Converse 200 or Vanguard 10E Enhanced - network services are not accessible by these keys. Only reprogramming to PSTN numbers will be effective. Any required network services must be accessed from the keypad.

Relate 200 Enhanced - Reprogramming of Charge Advice and Call Waiting is necessary. To set for Charge Advice, enter RECALL, RECALL, PAUSE, *', 40, #. To set for Call Waiting, enter RECALL, RECALL, PAUSE, 2.

From week 3 3/93 all Converse 200 & 300 telephones should be fully compatible with Renown and 2+8 systems. From that date all instruments will incorporate the following modifications:-
1) Mechanical Recall switch.
2) Tone caller which operates to lower input voltage.

A side effect of '2' is that the overall audible ringing level has been slightly reduced. This may cause comparison problems where telephones are changed and the new model replaces the old. The RENs are unchanged.

Some early feedback has indicated that the operation of the new recall key on the Converse 300 may be unreliable. The modified version can be identified by its week of manufacture: 33/93 or later.

When connected as the Carrier subscriber on a WB900, Renown extensions may be unable to access the line to make an outgoing call. When this occurs, Systemphone LED's incorrectly indicate the free line is busy. The condition will clear on receipt of an incoming call which can be answered in the normal manner.

The problem should be overcome if the Line/PBX voltage is reset to 24V by powering down and moving Switch 1 to the down position.

In brief, the Converse ringer was designed to provide a higher than normal output and so requires slightly more ringing current than most other telephones. The Converse is provided with three ringing settings: R1, R2 and R3 and three ringing volume settings: OFF, LO and HI.

As the ringing output of the Renown system is limited, difficulties can be experienced with R3, and possibly R2, if the volume is set to HI. Only R1 may be found to be satisfactory on HI, but all three settings should function adequately on LO.

Following a number of complaints, the handset retaining lug of Renown Systemphones has been modified to prevent the handset continually falling off when the instrument is wall mounted. This has been a particular problem where the wall is subject to frequent vibration - such as close to a door.

Although all new Systemphones will shortly incorporate the modification, the number of wall-mounted Systemphones currently in situ and prone to this problem is unknown.

Where a Renown system is installed before exchange services has been provided, internal dial tone may be temporarily lost from extension 1.

With no exchange line connected and the system powered up, system dial tone will be present at extensions 2, 3 and 4, but be absent from the first extension. This is not a fault and normal internal service will be restored as soon as the exchange line is provided. Systemphone LED's will indicate the line is busy.

Similarly, if the exchange line is disconnected during normal service with a subsequent power reset, system dial tone will be lost from extn 1. If no power reset occurs while the line is disconnected, internal dial tone will remain at all stations.

This complaint has yet to be resolved. More evidence is required to establish the extent of the problem.

If immediate action must be taken, replacement with a MK1 Systemphone should overcome the problem.


System picture courtesy of Rocom Ltd

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Last revised: May 03, 2024