Description
Technical Specifications
| Parameter Name | Parameter Value |
|---|---|
| Product Model | Belden 9729 (put-ups: 9729 060100, 9729 060500, 9729 0601000, 9729 0605000, 9729 06010000) |
| Manufacturer | Belden Inc. |
| Product Type | Multi-Conductor Shielded Twisted-Pair Cable (Low-Capacitance Computer / Instrumentation Cable) |
| Conductor Configuration | 2 pairs, 4 conductors total, 24 AWG stranded 7×32 tinned copper |
| Insulation | Datalene foam polyethylene (FPE), 0.019 in (0.48 mm) wall, 0.061 in (1.5 mm) nominal diameter |
| Shielding | Individual Beldfoil (Z-Fold) aluminum/polyester tape per pair, 100% coverage, 24 AWG (7×32) TC drain wire |
| Outer Jacket | Chrome PVC, 0.048 in (1.2 mm) nominal wall thickness |
| Nominal Characteristic Impedance | 100 Ω |
| Nominal Capacitance | 12.5 pF/ft (41.0 pF/m) conductor-to-conductor; 23.2 pF/ft (76.1 pF/m) conductor-to-other and shield |
| Nominal DC Resistance | 28.8 Ω/1000 ft conductor; 17.42 Ω/1000 ft (57.15 Ω/km) inner shield |
| Nominal Velocity of Propagation | 76% |
| Nominal Inductance | 0.23 µH/ft (0.755 µH/m) |
| Voltage Rating | 300 V (CM), 30 V (UL AWM 2919) |
| Max. Recommended Current | 2.1 A per conductor at 25°C ambient |
| Temperature Range | -20°C to +80°C operating; 80°C UL rating (AWM Style 2919) |
| Overall Nominal Diameter | 0.266 in (6.76 mm) |
| Mechanical Limits | 2.7 in (69 mm) minimum bend radius; 27.5 lbs (12.5 kg) maximum pull tension |
| Bulk Cable Weight | 35 lbs/1000 ft (approx. 52 kg/km) |
| Compliance and Ratings | NEC Article 800 CM, CEC CM, UL AWM 2919, UL 1685 FT4 Loading, IEC 60332-1-2, CPR Euroclass Eca, CE, UKCA, RoHS 2, China RoHS II |
| Supported Signals and Protocols | EIA RS-232, RS-422, 4-20 mA, 0-10 V, 24 V digital control, digital audio (AES/EBU), DMX512 |
| Installation Environment | Indoor, non-plenum and non-riser; plenum equivalents are 89729 and 82729 |
Main Features and Advantages
Individually shielded pairs for true channel isolation: Every pair inside Belden 9729 is wrapped in its own Beldfoil aluminum-polyester tape at 100% coverage, with a dedicated 24 AWG stranded tinned copper drain wire bonded along it. This means the foil shield is not shared between channels, so a noisy transmit line cannot inject energy into a sensitive receive line or into an adjacent 4-20 mA loop. For engineers who have chased intermittent serial faults caused by crosstalk, this per-pair architecture is the practical cure, and it is one reason Belden 9729 is specified in mixed-signal panels where digital and analog traffic share the same tray.
Low-capacitance Datalene dielectric for longer, cleaner runs: The foamed polyethylene insulation gives Belden 9729 a low dielectric constant and low dissipation factor, producing the 12.5 pF/ft mutual capacitance and 76% velocity of propagation that define its performance class. Lower capacitance translates directly into two benefits: reduced signal distortion and the ability to run higher data rates or greater distances before the receiver’s eye pattern collapses. Combined with a controlled 100 Ω characteristic impedance, the cable behaves predictably at the terminations, which matters when RS-422 drivers and receivers have to work across hundreds of metres of plant wiring.
Mechanical practicality and global compliance: At 0.266 in (6.76 mm) overall diameter with finely stranded 7×32 conductors, the cable pulls through conduit and bends neatly inside crowded enclosures while still respecting a 2.7 in minimum bend radius and a 27.5 lbs pull tension limit. Tinned copper conductors resist corrosion and make soldered terminations reliable, and the chrome PVC jacket withstands abrasion and common industrial fluids. Because Belden 9729 carries CM, CE, UKCA, CPR Euroclass Eca and RoHS 2 approvals, the same part number can be used on machines destined for North America, Europe and Asia without redesigning the bill of materials.
Application Field
Serial data and industrial communications: The natural home of Belden 9729 is the EIA RS-232 and RS-422 link layer that still underpins a large share of installed automation. It is routinely used for point-to-point and multidrop links between PLCs, variable frequency drives, weigh controllers, barcode readers, HMIs and remote I/O drops, especially where distances exceed what unshielded cable can carry. Its per-pair shielding also suits RS-485-style differential pairs in lighter installations, and it is a documented recommendation in professional lighting control for DMX512 runs.
Low-voltage analog and digital control: In process and factory panels, Belden 9729 handles the low-energy signals that carry the actual measurement: 4-20 mA transmitter loops, 0-10 V command and feedback signals, 24 V digital control states, temperature and pressure sensor outputs, and the wiring to relays, solenoid valves, meters, actuators, contactors, push buttons and alarm annunciators. The individually shielded pairs are particularly valuable here, since a 4-20 mA loop running alongside a 24 V switching signal is otherwise a classic source of induced error.
Audio, broadcast and studio infrastructure: Because of its 100 Ω geometry, low capacitance and dual independent shields, Belden 9729 is widely adopted for digital audio interconnects, including AES/EBU balanced pairs, as well as line-level analog audio and general studio patching. Entertainment and architectural lighting systems, stage equipment racks and broadcast facilities use it where two channels must coexist in one cable run without audible or data-level interference.
Instrumentation, testing and machine building: OEM machine builders, test-bench integrators and lab instrumentation suppliers rely on Belden 9729 for internal panel wiring and for harnesses linking measurement cards to terminal blocks, since the cable’s 6.76 mm diameter and flexible stranding make dense routing practical while maintaining a documented, repeatable electrical specification across every build.
