Rtd Temperature - GE 845 Instruction Manual

CHAPTER 4: SETPOINTS

RTD Temperature

NOTE:
845 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
RTD Inputs
Hardware and software is provided to receive signals from external Resistance
Temperature Detectors (RTDs) and convert these signals into a digital format for use as
required.
Depending on the order code, the 845 can be furnished with up to two optional RTD cards.
Each card has six RTD input channels. Only slots "B" and "C" can accept RTD cards. When
two RTD cards are used, then inputs on the card inserted into slot "B" are labelled 1 to 6
and inputs on the card inserted into slot "C" are labelled 7 to 12.
If only one RTD card is ordered at the time the relay is ordered, this RTD card is always
shown in slot B. The order code selection does not allow for an RTD card in slot C, if no RTD
card is ordered in slot B.
An alphanumeric name is assigned to each channel; this name is included in the channel
actual values. It is also used to reference the channel as the input parameter to features
designed to measure this type of parameter. Selecting the type of RTD connected to the
channel configures the channel. The conversion chart is shown in the RTD Temperature vs.
Resistance table.
Table 4-53: RTD Temperature vs. Resistance
TEMPERATURE
°C
–40
–30
–20
–10
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
180
190
200
210
°F
–40
–22
–4
14
32
50
68
86
104
122
140
158
176
194
212
230
248
266
284
302
320
338
356
374
392
410
RTD TEMPERATURE
RESISTANCE (IN OHMS)
100 Ω PT (IEC 60751)
84.27
88.22
92.16
96.09
100.00
103.90
107.79
111.67
115.54
119.40
123.24
127.08
130.90
134.71
138.51
142.29
146.07
149.83
153.58
157.33
161.05
164.77
168.48
172.17
175.86
179.53
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