ABB Relion 670 Series Applications Manual page 488

Section 17
Monitoring
ExpectedLife : The transformer expected insulation life in hours can be set by this setting. As per
IEEE C57.91-1995 the normal life expectancy at a continuous hot spot temperature of 110 ̊ C is
180,000 Hours.
AgeingRateMeth : This setting is used to select the method to be used for transformer insulation
relative ageing rate calculation between IEC standard method and IEEE standard method. It has
the following options:
IEC : Transformer insulation age calculation based on IEC standard method.
•
IEEE : Transformer insulation age calculation based on IEEE standard method.
•
ThermalUpgrade : This setting is used to select the transformer insulation paper type between
thermally upgraded insulation and normal insulation. It has the following options:
Upgraded : The function considers the given transformer has thermally upgraded paper
•
insulation.
Normal : The function considers the given transformer has normal insulation.
•
TimeToUpdate : This setting is used to set the time interval for updating the transformer
insulation loss of life calculation outputs LOLINDAY and LOLINYRS. It can be selected as 1 hour/ 2
hour/ 4 hour/ 8 hour/ 12 hour/ 24 hour depending on user requirement.
Two settable warning levels are available for hot spot temperature with separate outputs. If
warning level exceeds for the set time, an alarm is generated.
IEEE C57.96-1995 has suggested maximum temperature limits for the four types of loading, see
table 53.
Table 53:
Type of temperature
Insulated winding
hot spot
temperature in °C
Top oil temperature
in °C
IEEE standard has also suggested the limits of temperature and load for loads higher than
transformer nameplate.
• For distribution transformers with 65°C hot spot temperature rise:
•
•
•
• For power transformer with 65°C hot spot temperature rise:
•
•
•
Settings related to warning and alarm are:
482
Suggested maximum temperature limits
Normal life
expectancy loading
120
105
Top oil temperature = 120°C
Hot spot winding temperature = 200°C
Short-time loading (1/2 h or less) = 300%
Top oil temperature = 110°C
Hot spot winding temperature = 180°C
Maximum loading = 200%
© Copyright 2017 ABB. All rights reserved
Planned loading Long term loading
beyond nameplate
rating
130 140
110 110
1MRK 511 401-UUS F
GUID-B170CF21-839E-4246-A607-55A8999FAD07 v1
Short term loading
180
110
Bay control REC670
Application manual