IDC


TELECOM INSTRUCTION
C MARKETING INSTALLATION
3 Internal
R8015
ISSUE 1 - DEC 1981

INSULATION DISPLACEMENT CONNECTION (IDC)

The principle of this method of wire termination is that the wire td be terminated is placed in the slot of a forked tag, pressure is applied by a spring-loaded impact tool (Inserter, Wire No 2A) to force the wire into the tag slot. At the end of the insertion stroke the surplus wire is cut off close to the tag. The insulation is displaced where the wire passes through the tag and the resultant contact between wire and tag makes a sound electrical and mechanical joint.

NOTE: No attempt should be made to terminate wires with any tool other than Inserter, Wire 2A (shown below); use of other tools will result in faulty terminations and/or damage to tag and connection strip.


CABLE AND WIRE
A new range of cables for ICD is being made available. These, in the Cable. Equipment, 2000 series, will incorporate conductors whose insulation is marked with a new colour code in which each wire carried a unique marking consisting of two colour bands, one band 3 times the width of the other. Each wire of a pair carries the same two colours but the colour of the wide ("base") colour band and the narrow band are reversed to identify the A and B wires. The colour code is designed to code up to 25 pairs.

The larger sizes of cable, up to 320 pairs, are made up in 20-pair units as necessary, repeating the colour code for each unit but identifying the units by individual lapping tapes.

The cables will be available with either white or black sheaths, black cable being intended for those cables in ICD schemes which are run externally, e.g. on walls.

Wire Connector 9000 Series A new range of jumper wire has been introduced for use with IDC tags (coded WIRE, CONNECTOR 9000 series). The insulation is softer than Wire, Jumper 7000 series (which must not be used with ICS tags); care should be taken when running jumpers to avoid damage to the insulation. The new colour code is used, the one-pair size using the colours YELLOW-blue, BLUE- yellow.

For short jumpers in small connection boxes, wires removed from Cable, Equipment 2000, or Wire Connector 1000 series can be used.

In cables made up from 20-pair units, the first unit in each cable layer is lapped with an ORANGE tape, the last unit is lapped with GREEN.

EQUIPMENT
Strip, Connection No. 237
This is a new range of connection strips incorporating an IDC tag. All types are physically similar, measuring approximately 120 mm long by 20 mm wide by 40 mm deep. Each has a capacity of 40 IDC tags (20 upper and 20 lower) each designed to terminate up to 2, solid, tinned copper conductors of between 0.4 mm and 0.63 mm diameter. When two wires are terminated in the same slot they must be of the same diameter and insulation material.

Strip, Connection No. 237A
Wiring capacity, 10 pairs in, 10 pairs out.
"Break" test springs ("Look-Both Ways" test).
Use, all positions on Building Distribution Frames and Test Jack Frames.

Strip, Connection No. 237B
NOTE: These may be encountered on early versions of prewired system "harnesses".
Wiring capacity, 10 pairs in, 10 pairs out.
"Non break" test springs (see note regarding test plugs).

Strip, Connection No. 237C
Wiring capacity, 20 pairs in, 20 pairs out by terminating 2 wires (i.e. one "in" and one "out") on each tag.
No test points
Use, through connections between cables in ICD schemes, e.g. "riser joints" and floor DPs.

Strip, Connection No. 237D
Wiring capacity, 76 wires. Used in Box Connections to distribute recall earth to PBX extension. 

Strip, Connection No. 237E
Wiring capacity 20 wires.  Earth-common strip for up to 20 wires (at 2 wires per tag); provided with a flexible, eyelet-terminated earth lead for connection to an (earthed) Frame, Mounting No. 5.....

Strip, Connection No. 243A
Wiring capacity 8 pairs.  Same as 237A but with reduced capacity.

Strip, Connection Nos. 241A and 242A
These, "low profile" strips are designed to be used where depth of accommodation is limited, (e.g. in floor outlet boxes).
The low profile tag will accommodate only one wire (0.4mm to 0.63mm diameter). Strip, Connection 241 will connect 10 pairs "in" to 10 pairs "out". Strip, Connection 242A will connect 20 pairs "in" to 20 pairs "out".

Accessories Used With Strip, Connection No. 237...

  1. Cord, Connection D94471 Test cord, terminated at one and with 4-way plug (Plug No. 440A) and at the other with separate bare wires.

  2. Cord Connection D94473 Patching cord, terminated at both ends in Plug No. 440A.
    Plug 440A is designed for insertion into the test springs of Strip, Connection 237A and connects to both "in" and "out" sides of the 2 conductors of a pair.
    NOTE: Plug 440A MUST NOT be used with Strip, Connection 237B or damage will result.

  3. Wedge, Locking No. 23A Disconnection wedge, to isolate a single circuit on Strip, Connection 237A.

  4. Wedge, Locking No. 24A "Blind" wedge for use with Strip, Connection 237A to prevent insertion of test plugs into priority circuits.

WEDGE, LOCKING 23A, 24A and PLUG 440A IN STRIP CONNECTION 237A
Strip, Designation No. 51A Label holder to identify individual circuits on a single Strip, Connection 237.. Clips on the face of a Strip, Connection, masking the permanent wiring but allowing access to the cross connection side. Cannot be used with Protector Mounting, Wedges Locking or Cover 116A.

Provision is made, on both sides of the hinged, plastic cover, to accommodate a locally produced paper label.

Strip, Designation No. 53A
Fixed label holder, provided instead of one Strip, Connection 237.. on Frame, Mounting No. 5/..... to identify the following group of Strips, Connection.

Strip, Designation No. 54A
Fixed label holder, similar to 53A, but one and a half times the width. Used in the top or bottom mounting position on Frame, Mounting 5/..... where more detailed marking is required.

Protector Mounting No. 5A
Plugs into the test springs of Strip, Connection 237A when surge protection is required and equipped with Protector No. 14A as and when needed.

The mounting must be removed to give access to the test springs; to ensure that the mounting is inserted right way up, a "wine glass" symbol is marked on its face.

Since the earth connection for the protectors is obtained through a spring contact from the mounting frame, it is essential that Frames, Mounting 5/ ... are effectively earthed.

Frame, Mounting No. 5/../...
Mounting frames for Strips, Connection 237.. are made in the form of an open-fronted "channel" with projections on the front edges to engage in slots in the connection strip moulding. When fully inserted, latches on the moulding lock into square holes in the mounting frame. (Connection strips can be removed from the mounting by releasing the latches with a small screwdriver).

In all normal applications, cabling to the connection strips is routed within the mounting frame; flexibility jumpering is routed outside the frame.

Frames are available in a range of lengths to accommodate up to 34 Strips, Connection 237.. Frame depth will be determined by the number and sizes of cables to be routed within it; for most applications, a depth of 30 mm will be standard.

If an essential need should arise for a frame of non-standard length or depth, an enquiry should be made (by telephone in the first instance) to THQ/ME/Rcs8.2.2.

Sizes of individual frames are specified by their description, as shown in the following example:

FRAME, MOUNTING No. 5/30/10/A
can be broken down as follows-

Frame, Mounting No. 5 - Generic title
30 - Depth of wiring channel. 30mm.
10 - Number of positions for Strips Connection 237... 10.
A - Pitch of drillings. standard.

When using Strips, Connection No. 237.. in a confined, but secure position (e.g. as a "joint" in a building riser) they and their mounting frame need not be housed in a connection box, the mounting frame being secured, directly, to a wall or cable tray. For this use, a moulded plastic dust cover (Cover No. 116A) which will span up to 10 strips will shortly become available; non-availability of Cover 116A should not be a reason for avoiding this method of use in the interim.

Box, Connection 100-Series
This range of connection boxes was introduced for field trial purposes and uses the housings of Box, Connection 1, 2 etc fitted with Frames mounting No. 5. They will not form part of the standard range of boxes with the exception that Box, Connection No. 105A will continue to be supplied until its supersession by Box, Connection No. 201A early in 1982.

Box, Connection No. 105A
20-pair Distribution Point, using one Strip, Connection 237C and one Strip, Connection 237E to terminate 20 instrument leads (A and B wires plus recall earth). Strips, Connection must be ordered separately. Dimensions, 175 mm high, 160 mm wide, 50 mm deep.

Box, Connection No. 105A may be sited on walls, pillars or within under-floor trunking systems (where space allows) following the principles laid down in C3 R8013. For ease of wiring, the connection strips should always be horizontal; all cables should be securely anchored outside or within the connection box.

Box, Connection 200-series
A range of connection boxes in sizes and capacities below those of the "modular" 300-series.  No 200-series connection boxes have yet been manufactured; they will be introduced as they become available.

Box, Connection 201A
20-pair DP (superseding Box, Connection 105A during 1982). Overall dimensions, 170 m long, 120 mm wide, 35 mm deep.

Box, Connection 201A will differ from 105A in that it will not use separate connection strips; Strips, Connection 241A (low profile) will be incorporated within the box to allow termination of up to 20 instrument leads (A and B wires plus recall earth).

Box, Connection No. 203A Capacity, up to 5 Strips, Connection 237, intended as a 100-pair "joint", using 5 Strips, Connection No. 237C.

Box, Connection 300-Series
The "Modular" box, capable of being equipped in a variety of ways and assembled, as a module, in a number of groupings.

The basic unit (Box, Connection No 300A) consists of a plastic base and cover, 320 mm long, 210 mm wide and 120 mm deep overall. The base is moulded to provide mounting points for Frames, mounting, Connectors 226, Jumper rings, Cable anchors, connecting plates etc in a wide variety of arrangements. The cover has removable side and end plates and is secured to the base by 2 it coin-slot headed" fixings. The cover end plates have "break-out" sections for cable entry.

Two or more modular boxes may be assembled (side-side or end-end) using connecting plates, to form groups of greater capacity than the single box; cover panels are removed to allow access for cabling and jumpering between units.

The 300-series includes a number of single boxes and assemblies, equipped in a variety of ways. Those most appropriate to ICD schemes are listed below.

Box, Connection No. 300A
Unequipped box.

Box, Connection No. 301A 
quipped with Frame, Mounting No. 5/30/10A and Earth Bar No. 5.

Box, Connection No. 302A
Equipped with Frame, Mounting No. 5/30/8/A and allowing space for up to 8 Connectors 226.....

Ancillary Items used with Box, Connection 300-Series, as required:

Cable Anchors
Plate, Cable fixing No. 1C "Push in" fitting to box base, used with,

Strap, Cable fixing No. 1B (200 mm buckle type)

Ring, Jumper No. 37A "Push in" fitting to box base.

Earth Bar No. 5A "Push in" fitting to box base, terminates up to 12, 1.5 sq. mm earth wires, with lead to earth Frame, Mounting No. 5/.....

Part No. 1/DCL/183 Box base clamp set, includes 2 screws.

Part No. 1/DPO/163 Connector No. 226 mounting post, in pairs with screw and Part No 5/DSC/575.

Fixing parts for Connectors 226
Top fixing, Part No. 5/DSC/575

Bottom fixing, Screw, 3 mm x 12 mm, Slotted Pan Head.

Screw, No. 8 x 12 mm (Thread Cutting)

Slotted Pan Head - for fixing items in Box, Connection 300-Series.

Slotted Countersunk - for fixing together Box Connection 300-Series bases.

Container, Document No 1A - A4 document holder - mounts in Box, Connection No. 300A.

Box, Connection 500-Series
A range of lockable steel enclosures, equipped with one or more Frames, Mounting No. 5/30/34/A and provision for mounting Connectors 226.

All are wall-mounting, fitted with jumper rings and are intended as small or medium Building Distribution Frames, system connection boxes or Test Jack Frames for PBXS.

Doors are capable of right - or left hand - hinging and are equipped with document pockets on the inside.

Box, Connection No. 510A
Dimensions, 1000 mm high, 300 mm wide, 150 mm deep.

Capacity, one 34-way mounting frame for 32 Strips, Connection No. 237A plus 2 Strips, Designation 53A or 54A - 320 cable pairs "in" and "out".

Mountings for up to 10 Connectors 226.

Box, Connection No 520A
Dimensions, 1000 mm high, 500 mm wide, 150 mm deep.

Capacity, two 34-way mounting frames for 64 Strips, Connection No. 237A plus 4 Strips, Designation 53A or 54A - 640 cable pairs "in" and "out".

Mountings for up to 20 Connectors 226.

Box, Connection No. 530A
Dimensions, 1000 mm high, 750 mm wide, 150 mm deep.

Capacity, three 34-way mounting frames for 96 Strips, Connection No. 237A plus 6 Strips, Designation 53A or 54A 960 cable pairs "in" and "out".

Mountings for up to 30 Connectors 226.

Distribution Frames
Two double sided distribution frames are available to mount Strips, Connection 237A. Both are intended as Building Distribution Frames in large installations (above the capability of Box, Connection No. 530A) but may combine the function of system test jack frame with distribution where the PBX equipment is suitably sited.

Frame, Distribution No. 100A
Dimensions, 1050 mm long, 2600 mm high, 650 = deep.

Two or more sections may be bolted together.

LINE SIDE consists of 5 verticals, each accepting 4 Frames, Mounting No. 5/60/21/A for a total of 80 Strips, Connection No. 237A plus Strips, Designation 53A or 54A.

Capacity, 800 pairs per vertical - 4000 pairs total.

EQUIPMENT SIDE consists of 6 horizontal levels, each accepting 6 Frames, Mounting No. 5/22/8/A or 5/22/10/A - a maximum of 60 Strips, Connection No. 237A per horizontal.

Capacity, 600 pairs per horizontal - 3600 pairs total.

Frame, Distribution No. 105A
Dimensions, 500 mm long, 2000 mm high, 300 mm deep.

Two or more sections may be bolted together. Frame, Distribution 105A can be mounted against a wall for single-sided use but this is not recommended.

Both sides of the frame are identical, consisting of 2 verticals each capable of mounting 64 Strips, Connection No. 237A plus Strips, Designation 53A or 54A. The mountings form part of the structure of the frame and are common to the two sides.

Capacity, 640 pairs per vertical - 1280 pairs per side - 2560 pairs total.

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