Page 521 - Motor_protection_and_control_Manual_motor_starters_ contactors

Influence of the length of conductors

used in contactor control circuit

Single control line length Contactor Opening (contactor with AC operated coil)
Under certain conditions, an AC operated contactor does not open when the control circuit is de-energized.
This is due to a critical capacity of the excessively long control circuit line and the type of contactor coil con-
trol layout (see diagrams A and B opposite). This may be caused by the following factors:
A841D – high control voltage
– low coil holding consumption
Wiring diagram A – low contactor drop-out voltage (according to IEC 60947-4-1: 0.2 to 0.75 x Uc).
Via maintained pushbutton and 2-core
cable (with a capacity of 0.2 μF/km, for If lines longer than those indicated are required, the following measures must be taken:
example). – select a contactor with a higher rating
– select a lower control voltage
– connect "Rp" resistance in parallel with the contactor coil:
10 3
R P = (with C in µF)
C
The table and graph below can be used to determine the single length of line feeders (distance between 5
the control device and the contactor coil) in relation to:
– the coil holding consumption VA
A840D – the supply voltage
Wiring diagram B – the capacity in μF/km (depending on the control layout).
Via momentary pushbutton plus hold-in Wiring diagrams A and B opposite show two supply and coil control wiring examples.
contact and 3-core cable (with a capacity
of 2 x 0.2 = 0.4 μF/km, for example).
Coil holding consumption (average value)
3-pole contactors AC control 4-pole contactors AC control
supply supply
50/60 Hz 50/60 Hz
AF09, AF12, AF16, AF26, AF30, AF38 2.2 VA AF09, AF16, AF26, AF38 2.2 VA
AF09Z, AF12Z, AF16Z, AF26Z, AF30Z, AF38Z 1.7 VA AF09Z, AF16Z, AF26Z, AF38Z 1.7 VA
AF40, AF52, AF65, AF80, AF96 4 VA AF40, AF52, AF80 4 VA
AF116, AF140, AF146 8.9 VA AF116, AF140, AF190, AF205 8 VA
AF190, AF205 9.3 VA AF265, AF305, AF370 16 VA
AF265, AF305, AF370 16.6 VA
AF400, AF460, AF580, AF750, AF1250 12 VA
AF1350, AF1650, AF2050, AF2650 48 VA

Permissible single length for the control circuit conductors on contactor opening:
Depending on the coil holding power consumption, on the supply voltage and on the control circuit conductor capacity.

1700 2000 2500 3300 5000 10000 24 V
Single line length in m 500 1000 1000 1000 2000 5000 48 V 60 V
2000
1000
2000
3000
3000
500
300
200 300 500 500 1000 2000 110 V
300
200 300 500 1000
200 220 V - 230 V
100 200 300
100 500
100 200 380 V - 400 V
50 100 300
50
50 100 200 500 V
30 660 V - 690 V
30 50
20 30
20 30 50 100
20
10 20 30
10 50
10
5 10 17 30
5
5 10 20
3
3 5
2 13 57 9 13 57 9 13 57 9
1.7 2 2.5 3.3 5 10
0.60 0.50 0.40 0.30 0.20 0.10 1 2 3 5 7 10 20 30 50 100 200 300 500 1000
2.2 Coil holding consumption in VA
Line capacitance in µF/km 1SBC100063S0201 1SBC100063S0201
Example AF16 contactor: Coil voltage Uc = 500 V, 50 Hz, 2.2 VA contactor coil holding consumption, control type: diagram A, via maintained
pushbutton, and 2-core cable with a capacity of 0.2 μF/km. Max. permissible length: 17 m.
ABB | 5/321