Engine Carbon Brushes Replacement-
Cement Mill 2
St.Dmitry
December 19, 2017
a) to build convenient for further work datasets based on the provided raw data;
b) preliminary separate exploratory data analysis of carbon brushes replacement of Cement Mill 2 engine;
c) care by outliers.
The input of the module is a csv file. The file contains an unordered dataset, with provided information of engine inspections since 2004 for each engine carbon brush. In case carbon brush was replaced due to deterioration - the event is signed by “1”, otherwise by “0”.
The outputs of the module are convenient for further work datasets based on the provided raw data.
Statistic information of maintenance periods and cases of carbon brushes replacement due to deterioration:
## Cement Mill 2 (February 2004 - February 2018)## Maintaneince days summary:## Min. 1st Qu. Median Mean 3rd Qu. Max.
## 0.00 24.75 27.00 31.14 31.00 528.00##
## Maintaneince days Outleirs:## lowerFarOut lowerOutliers upperOutliers upperFarOut
## 6.000 15.375 40.375 49.750##
## Replacement periods summary:## Min. 1st Qu. Median Mean 3rd Qu. Max.
## 0.0 62.0 235.0 308.1 447.5 2589.0##
## Replacement periods upperOutliers:## upperOutliers upperFarOut
## 1025.75 1604.00Graphical Presentation of the Data:
Box Plots of the “maintenance periods” and “cases of carbon brushes replacement”
Low “FarOut” Actually, low farOuts points (days of carbon brush replacement) mean that carbon brushes were replaced on the same day or after few days. In both cases, low farOuts might be entered same information twice- and must be removed from dataset.
Low “FarOut”
## Mill C R brushName brushType phase fromDate toDate Days
## 188 CM2 3 1 C3R01 E46F3 V 2016-01-20 2016-01-20 0
## 322 CM2 3 11 C3R11 E46F3 V 2016-01-20 2016-01-20 0
## 351 CM2 4 1 C4R01 E46F3 V 2016-01-20 2016-01-20 0
## 640 CM2 5 3 C5R03 E46F3 W 2016-01-20 2016-01-20 0
## 830 CM2 5 11 C5R11 E46F3 W 2016-01-20 2016-01-20 0
## 881 CM2 6 3 C6R03 E46F3 W 2016-01-20 2016-01-20 0
## 368 CM2 4 2 C4R02 E46F3 V 2016-11-16 2016-11-17 1
## 447 CM2 4 6 C4R06 E46F3 V 2016-11-16 2016-11-17 1
## 526 CM2 4 10 C4R10 E46F3 V 2016-11-16 2016-11-17 1
## 561 CM2 4 11 C4R11 E46F3 V 2016-11-16 2016-11-17 1
## 587 CM2 4 12 C4R12 E46F3 V 2016-11-16 2016-11-17 1
## 658 CM2 5 4 C5R04 E46F3 W 2016-11-16 2016-11-17 1
## 711 CM2 5 7 C5R07 E46F3 W 2016-11-16 2016-11-17 1
## 762 CM2 5 9 C5R09 E46F3 W 2016-11-16 2016-11-17 1
## 802 CM2 5 10 C5R10 E46F3 W 2016-11-16 2016-11-17 1
## 903 CM2 6 5 C6R05 E46F3 W 2016-11-16 2016-11-17 1
## 27 CM2 1 3 C1R03 E46F3 U 2017-02-20 2017-02-22 2
## 45 CM2 1 5 C1R05 E46F3 U 2017-02-20 2017-02-22 2
## 111 CM2 2 3 C2R03 E46F3 U 2017-02-20 2017-02-22 2
## 129 CM2 2 5 C2R05 E46F3 U 2017-02-20 2017-02-22 2
## 204 CM2 3 2 C3R02 E46F3 V 2017-02-20 2017-02-22 2
## 216 CM2 3 3 C3R03 E46F3 V 2017-02-20 2017-02-22 2
## 232 CM2 3 4 C3R04 E46F3 V 2017-02-20 2017-02-22 2
## 373 CM2 4 2 C4R02 E46F3 V 2017-02-20 2017-02-22 2
## 398 CM2 4 3 C4R03 E46F3 V 2017-02-20 2017-02-22 2
## 417 CM2 4 4 C4R04 E46F3 V 2017-02-20 2017-02-22 2
## 452 CM2 4 6 C4R06 E46F3 V 2017-02-20 2017-02-22 2
## 490 CM2 4 8 C4R08 E46F3 V 2017-02-20 2017-02-22 2
## 531 CM2 4 10 C4R10 E46F3 V 2017-02-20 2017-02-22 2
## 566 CM2 4 11 C4R11 E46F3 V 2017-02-20 2017-02-22 2
## 592 CM2 4 12 C4R12 E46F3 V 2017-02-20 2017-02-22 2
## 624 CM2 5 2 C5R02 E46F3 W 2017-02-20 2017-02-22 2
## 663 CM2 5 4 C5R04 E46F3 W 2017-02-20 2017-02-22 2
## 716 CM2 5 7 C5R07 E46F3 W 2017-02-20 2017-02-22 2
## 767 CM2 5 9 C5R09 E46F3 W 2017-02-20 2017-02-22 2
## 807 CM2 5 10 C5R10 E46F3 W 2017-02-20 2017-02-22 2
## 850 CM2 5 12 C5R12 E46F3 W 2017-02-20 2017-02-22 2
## 908 CM2 6 5 C6R05 E46F3 W 2017-02-20 2017-02-22 2
## 937 CM2 6 7 C6R07 E46F3 W 2017-02-20 2017-02-22 2
## 952 CM2 6 8 C6R08 E46F3 W 2017-02-20 2017-02-22 2
## 1002 CM2 6 12 C6R12 E46F3 W 2017-02-20 2017-02-22 2
## 366 CM2 4 2 C4R02 E46F3 V 2016-10-13 2016-10-27 14
## 445 CM2 4 6 C4R06 E46F3 V 2016-10-13 2016-10-27 14
## 524 CM2 4 10 C4R10 E46F3 V 2016-10-13 2016-10-27 14
## 559 CM2 4 11 C4R11 E46F3 V 2016-10-13 2016-10-27 14
## 585 CM2 4 12 C4R12 E46F3 V 2016-10-13 2016-10-27 14
## 656 CM2 5 4 C5R04 E46F3 W 2016-10-13 2016-10-27 14
## 709 CM2 5 7 C5R07 E46F3 W 2016-10-13 2016-10-27 14
## 760 CM2 5 9 C5R09 E46F3 W 2016-10-13 2016-10-27 14
## 800 CM2 5 10 C5R10 E46F3 W 2016-10-13 2016-10-27 14
## 847 CM2 5 12 C5R12 E46F3 W 2016-10-13 2016-10-27 14
## 901 CM2 6 5 C6R05 E46F3 W 2016-10-13 2016-10-27 14First quantile - most frequently replaced carbon brushes.
Here, it is easy to find out places, where carbon brushes were replaced significantly more frequently than a majority of carbon brushes of this engine. Presumably, these carbon brushes were affected by local factors (like a local clamping spring) more than common reasons (for this engine).
Fourth quantile - most rarely replaced carbon brushes.
This chart provides information about “frozen” (rarely replaced) carbon brushes. Probably “frozen” brushes have a relatively weak clamping spring - as result, the carbon brush, apparently, did not do the job at all. -For example carbon brush C2R8 - was not deteriorated more than seven years (The criterion for replacement is the size (deterioration) of the carbon brush).
We should take into account, that there are upper outliers in the maintenance list - the reason for extremely long intervals between maintenance is probably data loss of maintenance cases:
## dateDiff fromtDate toDate
## 1 44 2004-07-25 2004-09-07
## 2 63 2004-09-23 2004-11-25
## 3 45 2005-05-09 2005-06-23
## 4 42 2006-02-06 2006-03-20
## 5 49 2012-04-29 2012-06-17
## 6 528 2013-12-19 2015-05-31
## 7 150 2016-05-16 2016-10-13
## 8 44 2017-06-19 2017-08-02There is a chance that deteriorated carbon brushes had been replaced during those periods, but we have no information - and as result, we see the lifespan of them as outliers:
## brushName fromDate toDate Days
## 1 C1R02 2012-10-28 2017-06-19 1695
## 2 C1R07 2012-07-10 2017-04-25 1750
## 3 C1R08 2012-03-01 2015-09-09 1287
## 4 C1R09 2012-07-10 2016-03-14 1343
## 5 C1R10 2013-10-24 2017-03-15 1238
## 6 C1R12 2011-11-08 2015-10-28 1450
## 7 C2R01 2006-02-06 2010-03-24 1507
## 8 C2R02 2010-05-31 2016-11-17 2362
## 9 C2R03 2006-12-26 2010-01-21 1122
## 10 C2R03 2013-09-02 2017-01-18 1234
## 11 C2R04 2012-01-09 2015-11-29 1420
## 12 C2R07 2013-10-24 2016-12-28 1161
## 13 C2R08 2005-07-11 2008-08-07 1123
## 14 C2R08 2008-08-07 2015-09-09 2589
## 15 C2R09 2010-05-31 2016-03-14 2114
## 16 C2R11 2012-03-01 2015-10-28 1336
## 17 C2R12 2005-06-23 2008-06-08 1081
## 18 C2R12 2011-11-08 2015-10-28 1450
## 19 C3R01 2011-09-13 2016-01-20 1590
## 20 C3R07 2013-09-02 2016-12-05 1190
## 21 C3R10 2013-09-02 2018-01-07 1588
## 22 C4R01 2013-01-27 2016-01-20 1088
## 23 C4R03 2013-04-21 2017-02-20 1401
## 24 C4R12 2007-12-23 2010-11-14 1057
## 25 C5R01 2012-03-27 2015-07-23 1213
## 26 C5R05 2012-12-25 2015-10-28 1037
## 27 C5R07 2012-08-07 2016-10-13 1528
## 28 C6R02 2006-06-28 2010-08-23 1517
## 29 C6R05 2013-10-24 2016-10-13 1085
## 30 C6R07 2013-03-19 2016-02-17 1065
## 31 C6R11 2006-05-29 2010-01-21 1333In order to exclude the uncertainty- whether carbon brushes lifespan outliers are true, or results of information loss- we can test which of these time periods are overlapping (outliers of periods between maintenance and outliers of periods between carbon brushes replacement).
According to the table, except of C2R03, C4R12, C6R02, C6R11, other lifespan outliers might be a result of the lost information. For example, it looks like carbon brush C2R08 was not replaced for about seven years, but this period is overlapped with two periods of lost information, during which carbon brushes might have been replaced for several times.
For sure, we can only say, that C2R03(first case), C4R12, C6R11 carbon brushes were not replaced for about three years, and C6R02 more than five years. Except for those four cases, other 27 outliers are better to be removed from the dataset.
In the same way possible to analyze current data in order to predict probable problem (“burned” or “frozen” carbon brushes). This chart is based on current data, taken at February 2018.
“Importance” (to put attention) provides visual information about the number of days since last replacement- lower than second quintile, or upper then third quintile. The importance is calculated by the following principles: Maximum value - 10, is equivalent to the maximum distance from the second quantile down (for the low values -“burned” brushes) and from the third quantile up (for the upper values- “frozen” brushes) found in the whole engine history. The minimum value “1” - the number of days since last replacement, lays in the second or third quantiles.
Colors: green- the number of days since last replacement lays in third or second quintile;
red- “burned” brush - the number of days since last replacement and lifetime of the previous brush in this place lay in the first quintile;
blue- “frozen” brush- the number of days since last replacement lays in the fourth quintile.