Connection Between A Pt And Rtd Input Module - LG GLOFA G3F - RD3A User Manual

Chapter 2. SPECIFICATIONS
2.5

Connection between a Pt and RTD input module

Number of method of connection between Pt and RTD input module are three, that is, 2 -wired type, 3-
-
wired type and 4-wired type.
The resistance of the wires used to connect Pt to RTD input module should be 10 Ω or less per wire.
-
The same wire (in thickness, length, and kind, etc.) should be used for each channel.
REMARK
Σ The difference between the resistance values of the wires used should be 1 Ω or less, or the accuracy
shown in the Table 2.2 could not be satisfied.
Connection
Method
2-wired type
3-wired type
4-wired type
[Fig. 2.3] Method of Connection between Pt and RTD Input Module
*1: RTD (Pt100 or JPt1000)
*:2: Shielded wire
- The shields of the RTD and shields of wire should be connected to the FG of the RTD input
module.
Connection Example
2 - 7
Wire Conditions
ℵ wire resistance≤10Ω
ℑ wire resistance≤10Ω
ℜ wire resistance≤10Ω
The difference between the
resistance values of the wires ℵ and
ℑ : 1Ω or less
The difference between the
resistance values of the wires ℑ and
ℜ : 1Ω or less
The difference between the
resistance values of the wires ℜ and
ℵ : 1Ω or less