LS Industrial Systems Metasol Series - Earth Leakage Relay; Earth Leakage Relay Standard Table; Optional Relay - Earth Leakage (EL)

43
D
R S T N
EL Current
Ig = 220V/Re
EL current when Re is 10 ohm: 22A
(When complete grounding occurs)
High
Voltage
Transformer
Grounding
Resistance :Re
Earth Leakage
Current (Ig)
Low
Voltage
380V
Supply CT
Supply CT
2. Earth Leakage Relay
In low voltage 3P4W, when resistance gets
added between the transformer’s neutral wire
and ground(resistance grounding method) and
complete EL occurs to the phase, EL current
becomes phase voltage/grounding resistance.
Normally, when this current is below 30A, EL
can be detected via EL relay by using the CT
that LSIS provides. EL relay is a separate
purchase, When placing order, an external CT
which can detect leakage current is provided.
Refer to the below figure for installing the
supplied CT.
Wiring 1 Wiring 2
Digital Trip Relay
4. Relay Function
Optional Relay - Earth Leakage (EL)
Earth Leakage
Protection
(ZCP Needed)
Time Delay(ms)
Accuracy : 10%(In1A)
20%(In=0.5A)
Setting
t Min Trip Time(ms)
t Max Trip Time(ms)
D2
140
200
D1
60
140
D3
230
320
D4
350
500
D5
800
1000
Current setting (A)
IΔn
10.5 2 3 4 5 7 10 20 30
1. Earth Leakage Relay Standard Table