SAER Elettropompe MS-300, Инструкция по эксплуатации

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16
5.2 HOW TO DETERMINE THE POWER SUPPLY CABLE
To determine the size of the power cable for the submersible motor, the
following information is required:
- V: Rated value of input voltage (V)
- I: Current consumption of motor, indicated on the motor rating plate (A)
- L: Length of line
- Cosf: Motor power factor (indicated on the rating plate)
- Room temperature (
°
C)
- Current carrying capacity of cable
Choose the minimum cross-section from the value I of the rated current of
the motor, according to the maximum current carrying capacities of cables
indicated in Table 4. Quadripolar cables are used for cables up to a cross-
section of 35 mm˝, while unipolar cables are recommended for larger cross-
sections.
Table 4 indicates maximum current carrying capacities of cables according
to the number of lines that are connected in parallel:
just one line direct motor starting
stator motor starting
two lines star/delta starting
two lines in parallel in order to use lighter cables
four lines star/delta starting with double lines.
For star/delta starting, the current in the cables is equal to the rated current
divided by 1,73.
The maximum current carrying capacities of the cables shown in Table 4
apply for room temperatures of 30
°
C. If the room temperature is different
apply the correction factor.
The final choice of the cross-section of the cable is carried out by verifying
the voltage drop along the power line, by applying the following relation:
V% = 173 x I x L x (R x cos + X x sen ) / V
V% voltage drop in percent (must not exceed is 5%)
I = rated current in Amperes (for star/delta starting the value is 58%)
L = lenght of line in meters (for star/delta starting the lenght is double)
cos = power factor (indicated on the motor rating plate)
sen = ( 1-cos2 )
R,X = resistance and reactance of cable in ohm/metre (indicated in tab.4)
V = input voltage.
The following tables define the maximum lenght of the cables depending
on the power of the motor, input voltage, the size of the cables, all at a
room temperature of 30
°
C.
TAB. 4
Electrical cables - Direct starting - 3 phase motor
1,5
2,5
4
6
10
16
25
35
60
70
95
120
150
185
240
18
24
32
41
57
76
102
126
168
213
258
300
350
392
461
16
21
28
36
50
68
89
110
146
185
224
261
305
341
401
14
19
26
33
46
61
82
101
134
170
206
240
280
314
369
15,1
9,08
5,63
3,73
2,27
1,43
0,907
0,654
0,473
0,326
0,236
0,188
0,153
0,123
0,0943
0,118
0,109
0,101
0,0955
0,0861
0,0817
0,0813
0,0753
0,101
0,0955
0,0955
0,0939
0,0928
0,0908
0,0902
Type of cable
Rated
cross-section
mm 2
Max. cable capacity
1 lines 2 lines 4 lines
A A A /Km /Km
Resistance Reatance
R X
178 265 439 706 1060
231 344 570 915
531 791
611 908
691 1028
127 189 313 503 755
167 248 412 660 990
378 563 834
435 847 1073
500 743
95 142 235 377 566 822
131 194 321 515 772
284 422 700
335 498 825
390 580 961
63 94 156 251 377 615 963
87 129 241 344 515 636
189 282 467 750
223 332 550 883
260 387 641 1027
51 76 127 203 305 497 780
67 99 164 263 395 642 1003
153 228 377 606 911
176 261 433 698 1045
199 296 491 787
39 59 97 156 234 382 599 926
52 77 127 204 307 499 779
117 175 290 465 899
135 201 333 534 802
155 230 381 611 917
220
240
380
400
415
220
240
380
400
415
220
240
380
400
415
220
240
380
400
415
220
240
380
400
415
220
240
380
400
415
1,9
1,7
1,1
1,0
1,0
2,7
2,5
1,6
1,5
1,4
3,6
3,3
2,1
2,0
1,9
5,4
5,0
3,1
3,0
2,9
6,6
6,1
3,8
3,6
3,5
8,5
7,8
4,9
4,7
4,5
0,5
0,75
1
1,5
2
3
0,37
0,55
0,75
1,1
1,5
2,2
HP kW V A 1 1,5 2,5 4 6 10 16 25
Rated poxer
of motor
Rated
voltage
Rated
current
Cable section (mm
2
) - Quadripolar cables
Max. cable lenght with 5% voltage drop
Quadripole
Quadripole
Quadripole
Quadripole
Quadripole
Quadripole
Quadripole
Quadripole
Unipolar
Unipolar
Unipolar
Unipolar
Unipolar
Unipolar
Unipolar