Understanding the 50 pair telephone cable color code is essential for telecommunication professionals, electricians, and installers working with large telephone trunk cables. These cables are commonly used in commercial buildings, PBX systems, and campus networks to carry multiple voice or data lines through a single bundled cable.
What Is a 50 Pair Telephone Cable?
A 50 pair telephone cable contains 100 color-coded insulated copper wires, organized into 50 twisted pairs. Each pair is designed to carry a balanced signal for analog voice or digital data communication.
These cables are most often used in:
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Multi-line telephone systems (PBX)
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Central office to customer premises wiring
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Multi-tenant buildings
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Inter-building campus communication
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Alarm and low-voltage signal systems
50 Pair Telephone Cable Color Code
Standard 50 Pair Color Code Chart
The color code system for multi-pair telephone cables follows the 25-pair color code standard, which uses:
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Primary (major) colors: White, Red, Black, Yellow, Violet
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Secondary (minor) colors: Blue, Orange, Green, Brown, Slate (gray)
Each pair consists of one wire from each group.
Pair Color Combination Chart (Pairs 1–25):
25 Pair Color Code
| Pair # | Tip (Major) | Ring (Minor) |
|---|---|---|
| 1 | White | Blue |
| 2 | White | Orange |
| 3 | White | Green |
| 4 | White | Brown |
| 5 | White | Slate |
| 6 | Red | Blue |
| 7 | Red | Orange |
| 8 | Red | Green |
| 9 | Red | Brown |
| 10 | Red | Slate |
| 11 | Black | Blue |
| 12 | Black | Orange |
| 13 | Black | Green |
| 14 | Black | Brown |
| 15 | Black | Slate |
| 16 | Yellow | Blue |
| 17 | Yellow | Orange |
| 18 | Yellow | Green |
| 19 | Yellow | Brown |
| 20 | Yellow | Slate |
| 21 | Violet | Blue |
| 22 | Violet | Orange |
| 23 | Violet | Green |
| 24 | Violet | Brown |
| 25 | Violet | Slate |
Pairs 26–50
After pair 25, the major colors repeat with a ring around the primary color or different stripe configuration to denote the second group of 25 pairs (26–50). These wires often use different printing or banding to distinguish them from the first 25 pairs.
For larger installations, pair identification charts or pre-marked jackets are often used.
Tips for Working with 50 Pair Cables
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Use a color code reference chart on hand at all times
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Always test for continuity and polarity before terminating
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Use gel-filled or flooded core cables for outdoor/direct burial installations
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Label and document each pair if re-termination or future troubleshooting is required
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Use 66 blocks, 110 blocks, or punch-down panels for terminations
Applications for 50 Pair Telephone Cable
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Voice lines for office buildings or campuses
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ISDN and DSL circuits
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Alarm system wiring
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Audio intercom systems
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Data signaling (RS485, Modbus in low-speed setups)
Need Bulk 50 Pair Telephone Cable?
At TOT Wire & Cable, we supply high-quality multi-pair telephone cables for voice and low-voltage communication. Our inventory includes:
✅ 25 pair, 50 pair, and 100 pair counts
✅ Indoor/outdoor rated jackets
✅ Shielded and unshielded options
✅ Color code compliant to ANSI/TIA/EIA-568
Need help with specs or installation guides? Contact our support team for expert advice and bulk pricing.
