Each Norstar telephone set requires a dedicated 4-conductor (2-pair) cable run from the telephone to the KSU (or to a station module). Norstar uses a proprietary digital signaling protocol over this cable — do not attempt to share a station run with analog devices.
| Station Cable Specifications |
|
| Parameter |
Minimum |
Notes |
| Cable type |
2-pair (4-conductor) |
Cat 3 or better; UTP or STP |
| Wire gauge |
24 AWG |
22 AWG allows greater max distance |
| Max loop resistance |
104 ohms |
Measured tip-to-ring, one pair |
| Max run — 24 AWG |
300 m (1,000 ft) |
Approximate; verify loop resistance |
| Max run — 22 AWG |
450 m (1,500 ft) |
Approximate; verify loop resistance |
| Connector (set end) |
RJ-11 / RJ-14 (6-pin) |
Uses centre 4 pins (2, 3, 4, 5) |
| KSU termination |
66/110 block or AMP 50-pin |
Via distribution frame, then to KSU port |
| Station Port Pin Assignment (RJ-14 / 6-Pin) |
|
| Pin |
Function |
Pair |
| Pin 2 |
D-channel (data) — A-lead |
Pair 2 (outer pair) |
| Pin 3 |
D-channel (data) — B-lead |
Pair 2 (outer pair) |
| Pin 4 |
Tip — voice / power |
Pair 1 (inner pair) |
| Pin 5 |
Ring — voice / power |
Pair 1 (inner pair) |
Important: Norstar sets draw operating power from the KSU over the station cable (the inner pair). Never connect a Norstar station port to a standard analog telephone or POTS line — the polarity and voltage levels are not compatible with analog equipment.
| CO Line Wiring (Analog Trunk Ports) |
|
| Pin |
Function |
Notes |
| Pin 4 |
Tip |
Standard telco Tip (typically –48 V loop) |
| Pin 5 |
Ring |
Standard telco Ring (typically 0 V / battery) |
CO lines connect via standard RJ-11 jacks. Use one jack per trunk. On a 25-pair distribution, each successive pair supplies the next CO line port.
T1 / PRI (RJ-48C, 8-pin): Used with Norstar T1 Trunk Cartridge or BRI/PRI cards.
| Pin |
Function |
Notes |
| Pin 1 |
Receive Ring (RX–) |
Pair from carrier (incoming) |
| Pin 2 |
Receive Tip (RX+) |
|
| Pin 4 |
Transmit Ring (TX–) |
Pair to carrier (outgoing) |
| Pin 5 |
Transmit Tip (TX+) |
|
| Standard 25-Pair Color Code (Bellcore / AT&T) |
|
| Pair |
Tip Color |
Ring Color |
| 1 | White / Blue stripe | Blue / White stripe |
| 2 | White / Orange stripe | Orange / White stripe |
| 3 | White / Green stripe | Green / White stripe |
| 4 | White / Brown stripe | Brown / White stripe |
| 5 | White / Slate stripe | Slate / White stripe |
| 6 | Red / Blue stripe | Blue / Red stripe |
| 7 | Red / Orange stripe | Orange / Red stripe |
| 8 | Red / Green stripe | Green / Red stripe |
| 9 | Red / Brown stripe | Brown / Red stripe |
| 10 | Red / Slate stripe | Slate / Red stripe |
| 11 | Black / Blue stripe | Blue / Black stripe |
| 12 | Black / Orange stripe | Orange / Black stripe |
| 13 | Black / Green stripe | Green / Black stripe |
| 14 | Black / Brown stripe | Brown / Black stripe |
| 15 | Black / Slate stripe | Slate / Black stripe |
| 16 | Yellow / Blue stripe | Blue / Yellow stripe |
| 17 | Yellow / Orange stripe | Orange / Yellow stripe |
| 18 | Yellow / Green stripe | Green / Yellow stripe |
| 19 | Yellow / Brown stripe | Brown / Yellow stripe |
| 20 | Yellow / Slate stripe | Slate / Yellow stripe |
| 21 | Violet / Blue stripe | Blue / Violet stripe |
| 22 | Violet / Orange stripe | Orange / Violet stripe |
| 23 | Violet / Green stripe | Green / Violet stripe |
| 24 | Violet / Brown stripe | Brown / Violet stripe |
| 25 | Violet / Slate stripe | Slate / Violet stripe |
Usage: On a 50-pin Champ/AMP connector, odd pins (1, 3, 5…) carry tips in pair order; even pins (2, 4, 6…) carry rings. Pair 1 = pins 1 & 26; Pair 2 = pins 2 & 27, etc.
| 4-Conductor Station Cable Color Code |
|
| Color |
Pair |
Function |
| Green |
Pair 1 — Tip |
Voice/power, Pin 4 of RJ-11 |
| Red |
Pair 1 — Ring |
Voice/power, Pin 5 of RJ-11 |
| Black |
Pair 2 — A-lead |
D-channel data, Pin 2 of RJ-11 |
| Yellow |
Pair 2 — B-lead |
D-channel data, Pin 3 of RJ-11 |
Cable using blue/white convention: Blue = Tip (Pin 4), White/Orange = Ring (Pin 5), White/Blue = A-lead (Pin 2), Orange = B-lead (Pin 3). Verify pair assignments with a meter on first installation.
|
|
|
| System |
Lines |
Stations |
| 3x8 |
3 |
8 |
| 6x16 |
6 |
16 |
| CICS |
8 |
24 |
| ICS (base) |
8 |
16 |
| ICS (expanded) |
16 |
64 |
Do:
- Use twisted-pair cable for all runs
- Maintain at least 15 cm (6 in) separation from 110/220 V AC wiring
- Ground the KSU chassis to a clean building ground
- Label every pair at both ends
- Test loop resistance before connecting sets
- Install a surge protector on CO line entry points
Don't:
- Run station cable parallel to fluorescent lighting ballasts
- Use solid-conductor cable for runs with frequent movement
- Exceed 104 ohms loop resistance on any station run
- Connect analog devices to Norstar station ports
- Coil excess cable — terminate neatly or trim to length
| T-Adapter (Two Sets / One Port) |
|
A T-adapter (also called a Norstar T) allows two telephone sets to share a single KSU station port. Both sets ring, but only one can be active at a time. Note:
- Both sets display the same DN
- Feature keys are mirrored on both sets
- Not supported with CAP/DSS modules
- Maximum cable distance still applies from KSU to first set
| Symptom |
Likely Cause |
| Set won't power up |
Open inner pair (Pins 4&5) |
| Set powers but no display |
Open outer pair (Pins 2&3) |
| Intermittent drops |
High resistance / poor termination |
| Hum / noise on calls |
Untwisted pair, AC proximity |
| Echo / crosstalk |
Split pair or improper termination |
| Can't register to KSU |
Reversed polarity or wrong port |
|
Note: Always de-energize the KSU before adding or moving station cables. Norstar station ports supply DC power and hot-plugging can damage the trunk card or the telephone set.
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