LR2K0312 TELEMECANIQUE, LR2K0312 Datasheet - Page 24
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LR2K0312
Manufacturer Part Number
LR2K0312
Description
RELAY, OVERLOAD, MINIATURE, CLASS 10, 3.7 TO 5.5 AMPS
Manufacturer
TELEMECANIQUE
Type
Overloadr
Datasheet
1.LP1K0910BD.pdf
(28 pages)
Specifications of LR2K0312
Contact Rating
3.7 to 5.5 A
Current, Rating Max
5.5
Function
Overload
Number Of Circuits
1
Number Of Poles
3
Primary Type
Contactor
Relay Type
Electro Mechanical
Reset Type
Manual or Auto
Standard Tripping Time
Between 4 and 10 Sec. for 7.2 Times the Setting Current
Dimensions (l × W × H, Mm)
58 × 45 × 65
Long Distance Control Data
24
Lone Distance Control Data
Voltage Drop Caused by the Inrush Current
When the operating coil of a relay is energized, the inrush current produces a voltage drop in the control supply cable caused by the resistance of the
conductors, which can adversely affect closing of the relay.
An excessive voltage drop in the control supply cables (both a.c. and d.c.) can lead to non closure of the relay poles or even destruction of the coil due
to overheating.
This phenomenon is aggravated by:
- a long line,
- a low control circuit voltage,
- a cable with a small cross-sectional area (c.s.a.)
- a high inrush power drawn by the coil.
The maximum length of cable, depending on the control voltage, the inrush power and the conductor c.s.a. is indicated in the graphs below.
Remedial Action
To reduce the voltage drop at switch-on:
- increase the conductor c.s.a.
- use a higher control circuit voltage
- use an intermediate control relay.
Selection of Conductor c.s.a.
These graphs are for a maximum line voltage drop of 5%. They give a direct indication of the copper conductor c.s.a. to be used for the control circuit
cable, depending on its length, the inrush power drawn by the relay coil and the control circuit voltage (see example page 25).
1 24 Vac
2 48 Vac
7 24 Vdc
8 48 Vdc
(1)
(2)
For 3-wire control, the current only flows in 2 of the conductors.
This is the length of the cable comprising 2 or 3 conductors (Distance between the relay and the control device).
1000
1000
100
100
0,1
0,1
10
10
1
1
1
1
5
5
3 115 Vac
4 230 Vac
9 125 Vdc
10c 250 Vdc
10
10
©
2001 Schneider Electric All Rights Reserved
50 100 200
50 100 200
Inrush power drawn in VA
X
Total resistance of the 2 conductors of the control circuit in
Total resistance of the 2 conductors of the control circuit in
Inrush power drawn in VA
10
9
8
7
6
5
4
3
2
1
500 1000 2000
500 1000 2000
5 400 V
6 690 Vac
Size of Copper Wires
A # 20 AWG (0.75 mm
B # 18 AWG (1 mm
Size of Copper Wires
A # 20 AWG (0.75 mm
B # 18 AWG (1 mm
1000
1000
100
100
0,1
0,1
10
10
1
1
10
10
50
50
2
2
)
)
2
2
) C # 16 AWG (1.5 mm
) C # 16 AWG (1.5 mm
100150
100 150
B
D
F
B
D
F
D # 14 AWG (2.5 mm
D # 14 AWG (2.5 mm
(1)
(1)
A
C
E
A
E
C
Length of control cable in m (2)
Length of control cable in m (2)
500 1000
500 1000
Y
2
2
2
2
) E # 12 AWG (4 mm
) F # 10 AWG (6 mm
) E # 12 AWG (4 mm
) F # 10 AWG (6 mm
5000 10 000
500010 000
04/01
2
2
2
2
)
)
)
)