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TECHN I CAL DATA
MOTOR P ROT ECT I ON & CAB L E S P R EAD I NG
240
Motor Approx. Full Load
Direct On Line
Star/Delta
Rating
Current (A)
MCCB Rating/Type
MCCB Rating/Type
HP KW @ 415V G J JM LS/LH N G J JM LS/LH N
10 7.5 14 25 25 – – – 25 25 – – –
12.5 9 17 25 25 – – – 25 25 – – –
15 11 21 25 25 – – – 25 25 – – –
20 15 28 32 32 – – – 32 32 – – –
25 19 35 40 – – – – 40 40 – – –
30 22 41 50 – 50 – – 50 50 50 – –
40 30 52
63 – 63 – – 63 63 63 – –
50 37 69 – – 80 – – – 80 80 – –
60 45 80 – – 100 – – – 100 100 – –
75 55 97 – – 125 – – – 125 125 – –
100 75 125 – – 160 – – – 160 160 – –
125 90 156 – – – 250 – – – 200 – –
150 112 190 – – – 315 – – – – 250 –
175 130 225 – – – 315 – – – – 315 –
200 149 255 – – – 315 – – – – 315 –
220 160 275 – – – 400 – – – – 400 –
250 186 320 – – – 400 – – – – 400 –
300 224 375 – – – 500 – – – – 500 –
350 261 449 – – – 630 600 – – – 630 600
400 298 505 – – – 630 600 – – – 630 600
The figures shown are based on motor starting conditions.
Direct online 7 x full load current for 5 seconds.
Star/Delta 4 x full load current for 12 seconds.
100
200
300
50
100
150
200
CAPACITOR SIZE (kVAr)
250
300
350
400
500
600
700
CIRCUIT BREAKER CURRENT (A)
MOTOR PROTECTION
CAPACITOR CIRCUIT
Circuit breakers are widely used to protect circuits containing
capacitors. Because of circuit harmonics and high “in rush” transients
associated with capacitor circuits it is necessary to select a circuit
breaker with a current rating not less than 1.5 times the capacitor
current.
Powerstar circuit breakers are suitable for off load switching
of capacitors only.
Cable Size
Dimension ‘A’
(
mm
2
)
(
mm
2
)
16
103
25
127
35
142
50
167
70
197
95
224
120
245
150
272
185
297
240
333
300
375
A
4
CORE TERMINATIONS, SPREADING ROOM
BS5372 SPREADING ROOM
The scope of BS5372 relates to dimensions which should be observed
in the design of cable terminations, having uninsulated conductor fittings,
for external cables on electrical equipment to enable the cables to be
connected satisfactorily.
The standard is based upon the use of compression type conductor
terminations and allows for the cores to be crossed within the terminal
enclosure because this combination requires more space.
The diagram and table below gives the dimensions quoted by this standard.
l