4. Overload Relay Size & Contactor for Starter
OVER LOAD RELAY & CONTACTOR FOR STARTER
OVER LOAD RELAY & CONTACTOR FOR MOTOR STARTER:
TYPES OF OVER LOAD RELAY:
- Class 10: Would Trip after 10 seconds. 2. Class 20: Would Trip after 20 seconds. 3. Class 30: Would Trip after 30 seconds.
- Over Load Relay should be set 115% to 130% of Motor Full Load Current. * Class 10 is faster than Class 20 and Class 30 over Load Relay.
SIZE OF OVER LOAD RELAY:
Size
Amp Capacity
S00
0.1 To 0.4
0.4 To 0.6
1.6 To 6
3 To 12
S0
3 To 12
6 To 25
S2
6 To 25
13 To 50
S3
13 To 50
25 To 100
S6
50 To 200
S10 & S12
55 To 250
200 To 540
300 To 63
CONTACTOR COIL:
Coil Voltage (40 To 50 Hz) Suffix 24V T 48V W 110V To 127V A 220V To 240V B 277V H 380V To 415V L
TYPE OF CONTACTOR FOR STARTER:
Contactor
Application
AC1
Non-Inductive or Slightly Inductive ,Resistive Load
AC2
Slip Ring Motor
AC3
Squirrel Cage Motor
AC4
Rapid Start / Stop
AC5a
Switching of Electrical Discharge Lamp
AC5b
Switching of Electrical Incandescent Lamp
AC6a
Switching of Transformer
AC6b
Switching of Capacitor Bank
AC7a
Slightly Inductive Load in Household or same type load
AC7b
Motor Load in Household Application
AC8a
Hermetic refrigerant Compressor Motor with Manual O/L Reset
AC8b
Hermetic refrigerant Compressor Motor with Auto O/L Reset
AC12
Control of Restive Load and Solid State Load with optocoupler Isolation
AC13
Control of Restive Load and Solid State with T/C Isolation
AC14
Control of Small Electro Magnetic Load ( <72VA)
AC15
Control of Small Electro Magnetic Load ( >72VA)
MAKING AND BREAKING CAPACITY OF CONTACTOR:
Contactor Making Capacity(Amp) Breaking Capacity (Amp) AC1 1.5 X motor rated current 1.5 X motor rated current AC2 4 X motor rated current 4 X motor rated current AC3 10 X motor rated current 8 X motor rated current AC4 12 X motor rated current 10 X motor rated current AC5a 3 X motor rated current 3 X motor rated current AC5b 1.5 X motor rated current 1.5 X motor rated current AC6a 12 X motor rated current 10 X motor rated current AC6b 12 X motor rated current 10 X motor rated current AC7a 1.5 X motor rated current 1.5 X motor rated current AC7b 8 X motor rated current 8 X motor rated current AC8a 6 X motor rated current 6 X motor rated current AC8b 6 X motor rated current 6 X motor rated current AC12 AC13 10 X motor rated current 1.1 X motor rated current AC14 6 X motor rated current 6 X motor rated current AC15 10 X motor rated current 10 X motor rated current
CONTACTOR STATUS:
Contactor Status Continuity Between Pins (N/C) Non Continuity Between Pins (N/O)
Power Not Applied
32 and 33
21 and 22
11 and 12
A1 and A2
B1 and B2
Power Applied
21 and 22
32 and 33
11 and 12
A1 and A2
B1 and B2
MAIN CIRCUIT VOLTAGE OF O/L RELAY & CONTACTOR:
- A.C= 240V,415V 2. D.C=230V,460V,600V
CONTACTOR’S COIL VOLTAGE:
- A.C= 40V,220V,240V,415V 2. D.C=24V(For PLC),110V,230V,460V
RATED CURRENT OF CONTACTOR: (THERMAL AND INTERMEDIATE DUTY):
- A.C= 6,10,16,25,63,100,160,200,315,400,630,800 Amp 2. D.C= 16,20,80,160,315,1250,8000 Amp.
Contactor / Relay Setting / Fuse / Cable for DOL STARTER
H.P
KW
FLC
Contactor Size (Amp)
Relay setting
Fuse
Cable (mm2)
Min
Max
Cu
Allu
0.5
0.37
1
–
0.8
1.17
4
1
1.5
0.75
0.55
1.3
9
1
1.5
4
1
1.5
1
0.74
1.9
9
1.6
2.3
6
1.5
2.5
1.5
1.11
2.6
9
2
3
6
1.5
2.5
2
1.49
3.7
9
2.5
3.7
10
1.5
2.5
3
2.2
4.8
9
4
5.9
16
1.5
2.5
5
3.73
7.8
9
6.3
9.4
20
1.5
2.5
7
5.22
11.2
12
8
11.7
25
2.5
4
10
7.46
16
16
12.5
18.7
25
4
6
12.5
9.32
19
32
16
23.4
32
4
6
15
11.19
20.8
32
16
23.4
50
6
10
20
14.92
28
32
20
30
50
6
10
25
18.65
34
38
32
37.4
63
10
16
30
22.38
40
45
32
47
80
16
25
40
29.84
53
63
50
59
100
25
35
50
37.3
65
70
57
65.5
125
25
50
60
44.76
78
85
70
88.9
125
25
50
75
55.95
96
110
85
98.2
160
50
70
100
74.6
131
140
115
168
200
70
95
125
93.25
156
170
115
168
250
120
150
150
111.9
189
205
160
234
315
150
240
180
134.28
227
250
160
234
355
185
300
215
160.39
271
300
200
299
400
–
–
270
201.42
339
400
250
374
500
–
–
335
249.91
338
475
320
468
500
–
–
Relay Range & Back up Fuse for DOL Starter
H.P
KW
Full Load Current (amp)
Relay Rang(Amp)
Back Up Fuse
Min
Max
10
7.5
13.6
13 To 20
25
50
12.5
9.3
17
13 To 20
25
50
15
11.2
20
20 To 30
35
80
20
14.9
28
20 To 30
60
80
25
18.7
35
30 To 45
60
100
30
22.4
40
30 To 45
80
100
35
26.1
47
45 To 63
80
125
Relay Range & Back up Fuse for Star / Delta Starter
H.P
KW
Full Load C…