Allen-Bradley 81000-632-51-R RTD Sensor Cable 6ft

Product Overview

The 81000-632-51-R is a PT100 RTD temperature sensor cable assembly manufactured by Allen-Bradley (Rockwell Automation). It provides a 6-foot (1.8 meter) shielded connection between a PT100 resistance temperature detector and the control system input card. With ±0.15°C accuracy and a -40°C to +150°C sensing range, this assembly delivers precise temperature measurement for process control, motor bearing monitoring, and HVAC applications.

Key Specifications

• Sensor Type: PT100 RTD (Resistance Temperature Detector)
• Cable Length: 6 feet (1.8 meters)
• Temperature Range: -40°C to +150°C (-40°F to +302°F)
• Accuracy: ±0.15°C (±0.27°F)
• Response Time: < 5 seconds (in moving air)
• Cable Construction: Shielded, multi-conductor
• Connection: Terminal block or connector (per configuration)
• Application: Temperature monitoring in industrial control systems

Features & Benefits

1. High-Precision PT100 Element: ±0.15°C accuracy exceeds typical thermocouple performance for critical temperature loops.
2. Integrated Cable Assembly: Pre-wired 6-foot cable eliminates field splicing and reduces installation errors.
3. Shielded Construction: Braided or foil shield minimizes EMI pickup from motors, drives, and welders.
4. Wide Temperature Span: -40°C to +150°C range covers freezing, ambient, and elevated process temperatures.
5. Plug-and-Play Compatibility: Designed for direct connection to Allen-Bradley RTD input modules.

FAQ

Q: What is the difference between a PT100 RTD and a thermocouple?
A: A PT100 RTD uses platinum resistance that changes predictably with temperature, offering higher accuracy and stability than thermocouples. Thermocouples measure wider ranges but with lower precision.

Q: How many wires does the 81000-632-51-R cable assembly have?
A: PT100 assemblies typically use 3-wire or 4-wire configurations to compensate for lead resistance. Verify your specific part number suffix or connector type.

Q: Can I extend the cable beyond 6 feet?
A> Cable extension is possible using shielded RTD extension cable of the same gauge. For 3-wire RTDs, maintain equal length and gauge on all three conductors to preserve accuracy.

Installation Guide

• Mount the RTD probe in a thermowell or direct immersion point with adequate thread sealant.
• Route the shielded cable away from high-voltage AC power cables to prevent induced noise.
• Connect the RTD leads to the RTD input module terminals, matching wire colors to module labels.
• Ground the cable shield at one end only (typically at the PLC chassis) to avoid ground loops.
• Verify temperature reading against a calibrated reference thermometer at a known temperature point.

Selection Tips

• Probe Style: Select spring-loaded, bayonet, or threaded probe styles based on your thermowell or mounting hole geometry.
• Wire Configuration: Use 4-wire RTDs for highest accuracy in laboratory or custody-transfer applications. Use 3-wire for standard industrial control.
• Cable Length: The 6-foot length suits most cabinet-to-process distances. For longer runs, specify custom cable lengths or use junction boxes.
• Immersion Depth: Ensure the probe tip extends at least 10× the probe diameter into the process fluid for accurate sensing.