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.
- Class 20: Would Trip after 20 seconds.
- 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
- D.C=230V,460V,600V
Contactor’s Coil Voltage:
- A.C= 40V,220V,240V,415V
- 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
- 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 Current (amp) | Relay Rang(Amp) | Back Up Fuse | |
Min | Max | ||||
20 | 14.9 | 28 | 13 To 20 | 60 | 60 |
25 | 18.7 | 35 | 20 To 30 | 60 | 100 |
30 | 22.4 | 40 | 20 To 30 | 60 | 100 |
35 | 26.1 | 47 | 20 To 30 | 80 | 100 |
40 | 29.8 | 55 | 30 To 35 | 80 | 125 |
50 | 37.3 | 66 | 30 To 35 | 100 | 125 |
60 | 44.8 | 80 | 45 To 63 | 100 | 160 |
75 | 55.95 | 95 | 45 To 63 | 125 | 160 |