TABLE OF CONTENTS Appendix C

(1)

Appendix C

Flameproof transformer ...1

C.1 Load profile...1

C.1.1 Section 21 ...2

C.1.1.1 Morning shifts ...2

C.1.1.2 Afternoon shifts ...5

C.1.2 Section 61 ...9

C.1.2.1 Morning shifts ...9

C.1.2.2 Afternoon shifts ...12

C.2 Histogram ...16

C.2.1 Section 21 ...17

C.2.1.1 Morning shifts ...17

C.2.1.2 Afternoon shifts ...18

C.2.2 Section 61 ...19

C.2.2.1 Morning shifts ...19

C.2.2.2 Afternoon shifts ...20

(2)

APPENDIX C

FLAMEPROOF TRANSFORMER

The total consumption of the 1250 kVA flameproof transformer was measured at the

each section’s flameproof transformer. The flameproof transformer supply power to all

the equipment used in the production section. Measurements were made on the

supply to the CM and the GEB. The total consumption of the flameproof transformer

was then calculated. The flameproof transformer for a number of shifts as can be seen

in Table C-1.

Table C-1: Measuring period for a CM at each section.

Flameproof transformers are supplied with power from the MSU with a 95 mm

2

trailing

cable. The cable is rated for a current of 295 A at an ambient temperature of 30 °C.

The derating factor for an ambient temperature of 25 °C is 1.1, which gives a current

rating of 325 A at 11 kV for the cable. The 1250 kVA flameproof transformer is rated

for 656 A at the 1100 V side and 65.6 A at the 11 kV side.

C.1 LOAD PROFILE

The next section focuses on the load profiles of the 1250 kVA flameproof

transformers. Each graph shows the line voltage and the voltage limits, the load

current and rated current capacity of the transformer. The 30 minute period graph

shows the total load of the 1250 kVA flameproof transformer as well as the load

consumed by the Gate end boxes and the load consumed by the CM. The morning

shifts and afternoon shifts are separated as well as the measurements made at the

different sections.

17-May-2005 18-May-2005 19-May-2005 23-May-2005 24-May-2005 25-May-2005

Section 21 Morning shift

X

-

-tonnes/CM/shift

858 1320

1716

1320

1650

1749

Afternoon shift

X

-

-tonnes/CM/shift

2145

2112

2013

2310

1980

Section 61 Morning shift

-

X

tonnes/CM/shift

1740

2175

2233

1740

1450

2320

Afternoon shift

-

X

tonnes/CM/shift

1682

2552

2320

2030

2320

1160

(3)

C.1.1 SECTION 21

C.1.1.1 Morning shifts

Table C-2: Reasons for breakdowns and absent data.

Figure C.1-1: Load current and voltage for a 1250 kVA flameproof transformer –

17 May 2005.

Date

Time start Time stop Reason for breakdown or no data

17-May-2005

SOS

EOS

No CM current data - recorder faulty.

SOS

09:30

Conveyor belt - electrical fault.

12:35

14:05

CM trailing cable faulty.

18-May-2005

SOS

EOS

No CM current data - recorder faulty.

SOS

08:50

CM trailing cable faulty.

19-May-2005

07:20

08:30

CM trailing cable faulty.

0 200 400 600 800 1000 1200 6:30 7:30 8:30 9:30 10:30 11:30 12:30 13:30 14:30

Time (hh:mm)

Li

ne

V

ol

ta

ge

(V

)

0 100 200 300 400 500 600 700 800 900 1000 1100 1200

C

ur

re

nt

(A

)

Voltage (V) Voltage limit (upper) Voltage limit (lower) Current total (A) Transformer capacity (A)

(4)

Figure C.1-2: Load current and voltage for a 1250 kVA flameproof transformer

– 17 May 2005 (30 minute period).

Figure C.1-3: Load current and voltage for a 1250 kVA flameproof transformer –

18 May 2005.

0 200 400 600 800 1000 1200 9:30 9:35 9:40 9:45 9:50 9:55 10:00

Time (hh:mm)

Li

ne

V

ol

ta

ge

(V

)

0 100 200 300 400 500 600 700 800 900 1000 1100 1200

C

ur

re

nt

(A

)

Voltage (V) Voltage limit (upper) Voltage limit (lower) Current CM (A) Current GEB (A) Current total (A) Transformer capacity (A) 0 200 400 600 800 1000 1200 6:30 7:30 8:30 9:30 10:30 11:30 12:30 13:30 14:30

Time (hh:mm)

Li

ne

V

ol

ta

ge

(V

)

0 100 200 300 400 500 600 700 800 900 1000 1100 1200

C

ur

re

nt

(A

)

(5)

Figure C.1-4: Load current and voltage for a 1250 kVA flameproof transformer

– 18 May 2005 (30 minute period).

Figure C.1-5: Load current and voltage for a 1250 kVA flameproof transformer –

19 May 2005.

0 200 400 600 800 1000 9:30 9:35 9:40 9:45 9:50 9:55 10:00

Time (hh:mm)

Li

ne

V

ol

ta

ge

(V

)

0 100 200 300 400 500 600 700 800 900 1000 1100

C

ur

re

nt

(A

)

Time (hh:mm)

Li

ne

V

ol

ta

ge

(V

)

0 100 200 300 400 500 600 700 800 900 1000 1100 1200

C

ur

re

nt

(A

)

(6)

Figure C.1-6: Load current and voltage for a 1250 kVA flameproof transformer

– 19 May 2005 (30 minute period).

C.1.1.2 Afternoon shifts

Table C-3: Reasons for breakdowns and absent data.

0 200 400 600 800 1000 1200 11:30 11:35 11:40 11:45 11:50 11:55 12:00

Time (hh:mm)

Li

ne

V

ol

ta

ge

(V

)

0 100 200 300 400 500 600 700 800 900 1000 1100 1200

C

ur

re

nt

(A

)

Voltage (V) Voltage limit (upper) Voltage limit (lower) Current CM (A) Current GEB (A) Current total (A) Transformer capacity (A)

Date

Time start Time stop Reason for breakdown or no data

17-May-2005

SOS

EOS

No CM current data - recorder faulty.

23:23

EOS

No voltage data - recorder stopped recording.

23:53

EOS

No GEB current data - recorder stopped recording.

18-May-2005

SOS

EOS

No CM current data - recorder faulty.

20:30

EOS

No GEB current data - recorder stopped recording.

22:39

EOS

No voltage data - recorder stopped recording.

19-May-2005

20:53

EOS

No GEB current data - recorder stopped recording.

(7)

Figure C.1-7: Load current and voltage for a 1250 kVA flameproof transformer –

17 May 2005.

Figure C.1-8: Load current and voltage for a 1250 kVA flameproof transformer

– 17 May 2005 (30 minute period).

0 200 400 600 800 1000 15:30 16:30 17:30 18:30 19:30 20:30 21:30 22:30 23:30

Time (hh:mm)

Li

ne

V

ol

ta

ge

(V

)

0 100 200 300 400 500 600 700 800 900 1000 1100

C

ur

re

nt

(A

)

Voltage (V) Voltage limit (upper) Voltage limit (lower) Current total (A) Transformer capacity (A) 0 200 400 600 800 1000 1200 21:00 21:05 21:10 21:15 21:20 21:25 21:30

Time (hh:mm)

Li

ne

V

ol

ta

ge

(V

)

0 100 200 300 400 500 600 700 800 900 1000 1100 1200

C

ur

re

nt

(A

)

(8)

Figure C.1-9: Load current and voltage for a 1250 kVA flameproof transformer –

18 May 2005.

Figure C.1-10: Load current and voltage for a 1250 kVA flameproof transformer

– 18 May 2005 (30 minute period).

0 200 400 600 800 1000 1200 15:30 16:30 17:30 18:30 19:30 20:30 21:30 22:30 23:30

Time (hh:mm)

Li

ne

V

ol

ta

ge

(V

)

0 100 200 300 400 500 600 700 800 900 1000 1100 1200

C

ur

re

nt

(A

)

Time (hh:mm)

Li

ne

V

ol

ta

ge

(V

)

0 100 200 300 400 500 600 700 800 900 1000 1100 1200

C

ur

re

nt

(A

)

(9)

Figure C.1-11: Load current and voltage for a 1250 kVA flameproof transformer

– 19 May 2005.

Figure C.1-12: Load current and voltage for a 1250 kVA flameproof transformer

– 19 May 2005 (30 minute period).

0 200 400 600 800 1000 15:30 16:30 17:30 18:30 19:30 20:30 21:30 22:30

Time (hh:mm)

Li

ne

V

ol

ta

ge

(V

)

0 100 200 300 400 500 600 700 800 900 1000 1100

C

ur

re

nt

(A

)

Time (hh:mm)

Li

ne

V

ol

ta

ge

(V

)

0 100 200 300 400 500 600 700 800 900 1000 1100 1200

C

ur

re

nt

(A

)

(10)

C.1.2 SECTION 61

C.1.2.1 Morning shifts

Table C-4: Reasons for breakdowns and absent data.

Figure C.1-13: Load current and voltage for a 1250 kVA flameproof transformer

– 23 May 2005.

Date

Time start Time stop Reason for breakdown or no data

23-May-2005

SOS

EOS

CM current maximum limited to 315 A - data

recorder range settings faulty.

14:40

EOS

Conveyor belt lockout.

24-May-2005

SOS

09:10

GEB - Earth fault.

09:10

10:50

No service water.

25-May-2005

14:45

EOS

Conveyor belt torn - 12 m.

0 200 400 600 800 1000 1200 6:30 7:30 8:30 9:30 10:30 11:30 12:30 13:30 14:30

Time (hh:mm)

Li

ne

V

ol

ta

ge

(V

)

0 100 200 300 400 500 600 700 800 900 1000 1100 1200

C

ur

re

nt

(A

)

(11)

Figure C.1-14: Load current and voltage for a 1250 kVA flameproof transformer

– 23 May 2005 (30 minute period).

Figure C.1-15: Load current and voltage for a 1250 kVA flameproof transformer

– 24 May 2005.

0 200 400 600 800 1000 1200 6:30 7:30 8:30 9:30 10:30 11:30 12:30 13:30 14:30

Time (hh:mm)

Li

ne

V

ol

ta

ge

(V

)

0 100 200 300 400 500 600 700 800 900 1000 1100 1200

C

ur

re

nt

(A

)

Voltage (V) Voltage limit (upper) Voltage limit (lower) Current total (A) Transformer capacity (A) 0 200 400 600 800 1000 13:00 13:05 13:10 13:15 13:20 13:25 13:30

Time (hh:mm)

Li

ne

V

ol

ta

ge

(V

)

0 100 200 300 400 500 600 700 800 900 1000 1100

C

ur

re

nt

(A

)

(12)

Figure C.1-16: Load current and voltage for a 1250 kVA flameproof transformer

– 24 May 2005 (30 minute period).

Figure C.1-17: Load current and voltage for a 1250 kVA flameproof transformer

– 25 May 2005.

0 200 400 600 800 1000 1200 12:00 12:05 12:10 12:15 12:20 12:25 12:30

Time (hh:mm)

Li

ne

V

ol

ta

ge

(V

)

0 100 200 300 400 500 600 700 800 900 1000 1100 1200

C

ur

re

nt

(A

)

Time (hh:mm)

Li

ne

V

ol

ta

ge

(V

)

0 100 200 300 400 500 600 700 800 900 1000 1100 1200

C

ur

re

nt

(A

)

(13)

Figure C.1-18: Load current and voltage for a 1250 kVA flameproof transformer

– 25 May 2005 (30 minute period).

C.1.2.2 Afternoon shifts

Table C-5: Reasons for breakdowns and absent data.

Date

Time start Time stop Reason for breakdown or no data

23-May-2005

SOS

EOS

CM current maximum limited to 315 A - data

recorder range settings faulty.

22:00

EOS

No GEB current data - recorder stopped recording.

23:00

EOS

No voltage data - recorder stopped recording.

23:17

EOS

No CM current data - recorder stopped recording.

24-May-2005

21:00

EOS

No GEB current data - recorder stopped recording.

23:01

EOS

No voltage data - recorder stopped recording.

25-May-2005

19:20

20:45

Conveyor belt torn - 15 m.

21:10

EOS

Conveyor belt torn - 50 m.

18:30

EOS

No GEB current data - recorder stopped recording.

23:06

EOS

No voltage data - recorder stopped recording.

0 200 400 600 800 1000 14:00 14:05 14:10 14:15 14:20 14:25 14:30

Time (hh:mm)

Li

ne

V

ol

ta

ge

(V

)

0 100 200 300 400 500 600 700 800 900 1000 1100

C

ur

re

nt

(A

)

(14)

Figure C.1-19: Load current and voltage for a 1250 kVA flameproof transformer

– 23 May 2005.

Figure C.1-20: Load current and voltage for a 1250 kVA flameproof transformer

– 23 May 2005 (30 minute period).

0 200 400 600 800 1000 1200 15:30 16:30 17:30 18:30 19:30 20:30 21:30 22:30 23:30

Time (hh:mm)

Li

ne

V

ol

ta

ge

(V

)

0 100 200 300 400 500 600 700 800 900 1000 1100 1200

C

ur

re

nt

(A

)

Time (hh:mm)

Li

ne

V

ol

ta

ge

(V

)

0 100 200 300 400 500 600 700 800 900 1000 1100 1200

C

ur

re

nt

(A

)

(15)

Figure C.1-21: Load current and voltage for a 1250 kVA flameproof transformer

– 24 May 2005.

Figure C.1-22: Load current and voltage for a 1250 kVA flameproof transformer

– 24 May 2005 (30 minute period).

0 200 400 600 800 1000 15:30 16:30 17:30 18:30 19:30 20:30 21:30 22:30 23:30

Time (hh:mm)

Li

ne

V

ol

ta

ge

(V

)

0 100 200 300 400 500 600 700 800 900 1000 1100

C

ur

re

nt

(A

)

Time (hh:mm)

Li

ne

V

ol

ta

ge

(V

)

0 100 200 300 400 500 600 700 800 900 1000 1100 1200

C

ur

re

nt

(A

)

(16)

Figure C.1-23: Load current and voltage for a 1250 kVA flameproof transformer

– 25 May 2005.

Figure C.1-24: Load current and voltage for a 1250 kVA flameproof transformer

– 25 May 2005 (30 minute period).

0 200 400 600 800 1000 1200 15:30 16:30 17:30 18:30 19:30 20:30 21:30 22:30 23:31

Time (hh:mm)

Li

ne

V

ol

ta

ge

(V

)

0 100 200 300 400 500 600 700 800 900 1000 1100 1200

C

ur

re

nt

(A

)

Time (hh:mm)

Li

ne

V

ol

ta

ge

(V

)

0 100 200 300 400 500 600 700 800 900 1000 1100 1200

C

ur

re

nt

(A

)

(17)

C.2 HISTOGRAM

The next section focuses on the frequency with which a 1250 kVA flameproof

transformer consumed a certain load current. The graphs show the number of times a

certain current has been consumed. The tables give data about the tonnes produced

during the shift and the percentage time of the shift that power were consumed. The

time that the transformer has been over loaded or loaded within capacity is given as a

percentage of the actual producing time. The morning shifts and afternoon shifts are

separated as well as the measurements made at the different sections.

(18)

C.2.1 SECTION 21

C.2.1.1 Morning shifts

Table C-6: Data for the total consumption of a 1250 kVA flameproof transformer

in section 21.

Figure C.2-1: Histogram for current consumed by a 1250 kVA flameproof

transformer.

0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 0 _{30 60 90 120 150 180 210 240 270 300 330 360 390 420 450 480 510 540 570 600 630 660 690 720 750}

Current bins (A)

Fr

eq

ue

nc

y

17-May-05 18-May-05 19-May-05

Tonnes/CM/Shift

858 1320

1716

% Time of shift producing

61.15%

93.18%

87.58%

% of Production time underloaded

100.00%

97.19%

% of Production time overloaded

0.00%

2.81%

(19)

C.2.1.2 Afternoon shifts

Table C-7: Data for the total consumption of a 1250 kVA flameproof transformer

in section 21.

Figure C.2-2: Histogram for current consumed by a 1250 kVA flameproof

transformer.

0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 0 _{30 60 90 120 150 180 210 240 270 300 330 360 390 420 450 480 510 540 570 600 630 660 690 720 750}

Current bins (A)

Fr

eq

ue

nc

y

17-May-05 18-May-05 19-May-05

Tonnes/CM/Shift

2145

2112

2013

% Time of shift producing

97.23%

58.93%

97.74%

% of Production time underloaded

100.00%

97.25%

% of Production time overloaded

0.00%

2.75%

(20)

C.2.2 SECTION 61

C.2.2.1 Morning shifts

Table C-8: Data for the total consumption of a 1250 kVA flameproof transformer

in section 61.

Figure C.2-3: Histogram for current consumed by a 1250 kVA flameproof

transformer.

0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 0 _{30 60 90 120 150 180 210 240 270 300 330 360 390 420 450 480 510 540 570 600 630 660 690 720 750}

Current bins (A)

Fr

eq

ue

nc

y

23-May-05 24-May-05 25-May-05

Tonnes/CM/Shift

1740

1450

2320

% Time of shift producing

99.03%

81.24%

99.79%

% of Production time underloaded

100.00%

95.54%

91.44%

% of Production time overloaded

0.00%

4.46%

8.56%

(21)

C.2.2.2 Afternoon shifts

Table C-9: Data for the total consumption of a 1250 kVA flameproof transformer

in section 61.

Figure C.2-4: Histogram for current consumed by a 1250 kVA flameproof

transformer.

0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 0 _{30 60 90 120 150 180 210 240 270 300 330 360 390 420 450 480 510 540 570 600 630 660 690 720 750}