Schweitzer Engineering Laboratories, Inc. SEL-2414 Data Sheet
5
Figure 5 Comma-Separated File Format for Easy
Display, Analysis, and Archiving
Figure 6 Excel Graph of Trend Data
Transformer Thermal Monitoring
Transformer thermal modeling, per IEEE C57.91-2011
or the IEC 60076-7:2018 Ed. 2, is a standard feature in
the SEL-2414. Specify the SEL-2414 to provide this
capability for monitoring and protection of a single
three-phase transformer, a three-phase transformer with
tertiary windings (three-winding mode with separate CT
ratios), or three independent single-phase units. Use the
thermal element to activate a control action or issue a
warning or alarm when your transformer overheats or is
in danger of excessive insulation aging or loss-of-life.
Use the thermal event report to capture current hourly
and daily data about your transformer. Operating
temperature calculations are based on load currents, type
of cooling system, and actual temperature inputs
(ambient and top-oil). Use as many as four thermal
sensor inputs: a single ambient temperature transducer
and one transducer for top-oil temperature from each of
three single-phase transformers. Temperature data are
obtained via an internal RTD/thermocouple card or from
an external SEL-2600A RTD Module. While the
SEL-2414 can receive temperature data at any rate, the
thermal element uses the temperature data once per
minute.
The thermal element operates in one of three modes,
depending upon the presence or lack of measured
temperature inputs: 1) measured ambient and top-oil
temperature inputs, 2) measured ambient temperature
only, and 3) no measured temperature inputs. If the
device receives measured ambient and top-oil
temperatures, the thermal element calculates hot-spot
temperature. When the device receives a measurement of
ambient temperature without top-oil temperature, the
thermal element calculates the top-oil temperature and
hot-spot temperature. In the absence of any measured
ambient or top-oil temperatures, the thermal element
uses a default ambient temperature setting that you select
and calculates the top-oil and hot-spot temperatures. The
device uses hot-spot temperature as a basis for
calculating the insulation aging acceleration factor
(FAA) and loss-of-life quantities. Use the thermal
element to indicate alarm conditions and/or activate
control actions when one or more of the following
exceed settable limits:
➤Top-oil temperature
➤Winding hot-spot temperature
➤Insulation aging acceleration factor (FAA)
➤Daily loss-of-life
➤Total loss-of-life
Generate a thermal monitor report that indicates the
present thermal status of the transformer. Historical
thermal event reports and profile data are stored in the
device in hourly format for the previous 24 hours and in
daily format for the previous 31 days.
The thermal model can be used even if a current card is
not installed. Current magnitude data can be received
through IEC 61850 Ed. 2 or other communications
protocols.
Through-Fault Event Monitor
A through fault is an overcurrent event external to the
differential protection zone. Though a through fault is
not an in-zone event, the currents required to feed this
external fault can cause great stress on the apparatus
inside the differential protection zone. Through-fault cur-
rents can cause transformer winding displacement lead-
ing to mechanical damage and increased transformer
thermal wear because of mechanical stress of insulation
components in the transformer. The SEL-2414 through-
fault event monitor gathers current level, duration, and
date/time for each through fault. The monitor also calcu-
lates a I2t and cumulatively stores these data per-phase.
The SEL-2414 through-fault report also provides percent
of total through-fault accumulated according to the IEEE
Guide for Liquid-Immersed Transformer Through-Fault-
=>>CPR <Enter>
"REC_NUM","YEAR","MONTH","DAY","HOUR","MIN","SEC","MSEC","VA_MAG","VB_M
AG","VC_M
AG","AI301","AI302","AI303","AI304","AI305","AI306","1D7A"
14,2005,9,1,12,10,4,261,2092.127,2099.499,2089.107,-0.001,-0.000,
-0.001,-0.001,-
0.001,-0.001,"1190"
13,2005,9,1,12,15,3,982,2093.966,2099.176,2088.974,-0.001,-0.001,
-0.001,-0.000,-
0.001,-0.001,"11AC"
12,2005,9,1,12,20,4,82,2091.636,2099.117,2089.346,-0.001,-0.000,
-0.001,-0.001,-0
.001,-0.001,"115C"
11,2005,9,1,12,25,4,332,2092.435,2098.398,2088.487,-0.001,-0.001,
-0.001,-0.001,-
0.001,-0.001,"119C"
10,2005,9,1,12,30,4,36,2092.907,2098.208,2089.058,-0.001,-0.001,
-0.000,-0.001,-0
.001,-0.001,"115C"
9,2005,9,1,12,35,4,186,2093.153,2098.865,2089.091,-0.001,-0.000,
-0.001,-0.001,-0
.001,-0.001,"116F"
8,2005,9,1,12,40,3,978,2094.284,2098.926,2089.732,-0.001,-0.001,
-0.001,-0.001,-0
.001,-0.001,"1179"
