57Table 25 — MS/TP Wiring RecommendationsLEGENDTable 26 — Open System Wiring Specifications and Recommended VendorsLEGENDSPECIFICATION RECOMMMENDATIONCable Single twisted pair, low capacitance, CL2P, 22 AWG (7x30), TC foam FEP, plenum rated cableConductor 22 or 24 AWG stranded copper (tin plated)Insulation Foamed FEP 0.015 in. (0.381 mm) wall 0.060 in. (1.524 mm) O.D.Color Code Black/WhiteTwist Lay 2 in. (50.8 mm) lay on pair 6 twists/foot (20 twists/meter) nominalShielding Aluminum/Mylar shield with 24 AWG TC drain wireJacket SmokeGard Jacket (SmokeGard PVC) 0.021 in. (0.5334 mm) wall 0.175 in. (4.445 mm) O.D.Halar Jacket (E-CTFE) 0.010 in. (0.254 mm) wall 0.144 in. (3.6576 mm) O.D.DC Resistance 15.2 Ohms/1000 feet (50 Ohms/km) nominalCapacitance 12.5 pF/ft (41 pF/meter) nominal conductor to conductorCharacteristic Impedance 100 Ohms nominalWeight 12 lb/1000 feet (17.9 kg/km)UL Temperature Rating SmokeGard 167°F (75°C)Halar -40 to 302°F (-40 to 150°C)Voltage 300 Vac, power limitedListing UL: NEC CL2P, or betterFig. 37 — BT485 Terminator InstallationAWG — American Wire GageCL2P — Class 2 Plenum CableDC — Direct CurrentFEP — Fluorinated Ethylene PolymerNEC — National Electrical CodeO.D. — Outside DiameterTC — Tinned CopperUL — Underwriters LaboratoriesWIRING SPECIFICATIONS RECOMMENDED VENDORS AND PART NUMBERSWire Type Description Connect AirInternational Belden RMCORP ContractorsWire and CableMS/TPNetwork (RS-485)22 AWG, single twisted shielded pair, low capacitance, CL2P,TC foam FEP, plenum rated. See MS/TP Installation Guide forspecifications.W221P-22227 — 25160PV CLP0520LC24 AWG, single twisted shielded pair, low capacitance, CL2P,TC foam FEP, plenum rated. See MS/TP Installation Guidefor specifications.W241P-2000F 82841 25120-OR —Rnet 4 conductor, unshielded, CMP, 18 AWG, plenum rated. W184C-2099BLB 6302UE 21450 CLP0442AWG — American Wire GageCL2P — Class 2 Plenum CableCMP — Communications Plenum RatedFEP — Fluorinated Ethylene PolymerTC — Tinned Copper