Issue
PT1000 temperature sensors RTD Input
Product Line
EcoStruxure Building Operation
Environment
- AS Classic, ASP
- UI16, RTD-DI-16 - Central IO Module
- ASB, RPC, MPC
- Need for temperature to be extremely accurate
- PT1000 platinum resistance thermometer, RTD Resistance Temperature Detector
Cause
The AS Central IO Module Universal Inputs (UI16) were designed to interface to various thermistors that can have resistance values that are usually much higher than 1000 ohms. They were not designed to interface directly to a PT1000 RTD, and will not provide good accuracy when measuring these lower resistance sensors. The resistance input type was intended to allow for measuring the position of a 10K potentiometer that is used on some wall sensors. The accuracy specification for a resistance input is: +/-(7+0.004*R) ohms. This would result in an error of +/-11 ohms at 1000ohms – therefore a temperature measurement error approaching +/-3.0C.
Resolution
AS, ASP
For RTD PT1000 (Pt100, Pt1000, Ni1000, LG-Ni1000, JCI-Ni1000) use RTD-DI-16 - Central IO Module, then choose 2 or 3 wire RTD Temperature Input
ASB
Choose 2-wire RTD Temperature Input (Pt1000, Ni1000, LG-Ni1000, JCI-Ni1000)
RPC, MPC, MPV
Choose RTD Temperature Input (Pt1000, Ni1000, LG-Ni1000)
For more details see SpaceLogic Hardware Reference Guide
