GE TRANSFORMER MANAGEMENT RELAY 745 Instruction Manual page 248

8.4 DISPLAY, METERING, COMMUNICATIONS, AND ANALOG OUTPUTS
b) DETAILED CALIBRATION OF RTD INPUT
1. Alter the following setpoints. Set
and set
S2 SYSTEM SETUP
2. The measured values should be ±2°C or ±4°F. Alter the resistance applied to the RTD input (note the 3-input connec-
tion must be used for the measurements to be valid) as per the typical table below to simulate RTDs and verify accu-
racy of the measured values. View the measured values in
Refer to RTD tables included in this manual for calibration of resistance versus temperature.
Table 8–1: MEASURED RTD TEMPERATURE
RTD TYPE
100 Ω Platinum
120 Ω Nickel
100 Ω Nickel
c) AMBIENT TEMPERATURE BY MONTHLY AVERAGES
1. If the ambient temperature is entered as 12 monthly averages, program the value for the month during which the relay
is being commissioned.
2. Examine the
8
A2 METERING
ature.
3. Verify that values entered for other months do not affect the value for the present month.
8-10
Courtesy of NationalSwitchgear.com
S2 SYSTEM SETUP
AMBIENT TEMP
Ω
EXPECTED RTD READING
100 PLATINUM
RESISTANCE
°C
80.31 –50
100.00 0
119.39 50
138.50 100
157.32 150
175.84 200
194.08 250
86.17 –50
120.0 0
157.74 50
200.64 100
248.95 150
303.46 200
366.53 250
71.81 –50
100.00 0
131.45 50
167.20 100
207.45 150
252.88 200
305.44 250
AMBIENT TEMP
745 Transformer Management Relay
AMBIENT TEMP AMBIENT TEMPERATURE SENSING
to the desired type.
AMBIENT RTD TYPE
A2 METERING AMBIENT TEMP
MEASURED RTD TEMPERATURE
____°C ____°F (SELECT ONE)
°F
–58
32
122
212
302
392
482
–58
32
122
212
302
392
482
–58
32
122
212
302
392
482
actual value to verify the programmed temper-
AMBIENT TEMPERATURE
8 COMMISSIONING
to "Enabled"
.
AMBIENT TEMPERATURE
GE Multilin