GE Multilin 745

Metering745
Transformer Management Relay
Commissioning
http://www.GEindustrial.com/multilin
7–10
GE Multilin
3. Compare the displayed value of temperature against known temperature at the
location of the sensor. Use a thermometer or other means of obtaining actual
temperature.
An alternative approach is to perform a more detailed calibration per the procedure
outlined below.
b) Detailed Calibration of RTD Input
1. Alter the following setpoints. Set
S2 SYSTEM SETUP !" AMBIENT TEMP ! AMBIENT
TEMPERATURE SENSING to “Enabled” and set S2 SYSTEM SETUP !" AMBIENT TEMP
!" AMBIENT RTD TYPE to the desired type.
2. The measured values should be ±2°C or ±4°F. Alter the resistance applied to
the RTD input (note the 3-input connection must be used for the measurements
to be valid) as per the typical table below to simulate RTDs and verify accuracy
of the measured values. View the measured values in
A2 METERING !" AMBIENT
TEMP ! AMBIENT TEMPERATURE.
Refer to RTD tables included in this manual for calibration of resistance versus
temperature.
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
A2 METERING !" AMBIENT TEMP ! AMBIENT TEMPERATURE actual value
to verify the programmed temperature.
3. Verify that values entered for other months do not affect the value for the
present month.
Table 7–1: Measured RTD Temperature
RTD Type
100
Ω
Platinum
Resistance
Expected RTD
Reading
Measured RTD
Temperature
____°C ____°F
(select one)
°C °F
100 Ω Platinum 80.31 –50 –58
100.00 0 32
119.39 50 122
138.50 100 212
157.32 150 302
175.84 200 392
194.08 250 482
120 Ω Nickel 86.17 –50 –58
120.0 0 32
157.74 50 122
200.64 100 212
248.95 150 302
303.46 200 392
366.53 250 482
100 Ω Nickel 71.81 –50 –58
100.00 0 32
131.45 50 122
167.20 100 212
207.45 150 302
252.88 200 392
305.44 250 482