9
6.5. Operating Characteristics
Earth Fault element
Definite Time Lag (DTL)
Low set element
Standard Inverse 3 sec (SI3)
Standard Inverse 1.3 sec (SI1)
Very Inverse (VI)
Extremely Inverse (EI)
Long Time Inverse (LTI) or
Definite Time Lag (DTL)
DTL Operating time
0 to 20.00 sec in steps of 0.01 sec
IDMTL Operating Time can be calculated as follows
K x T
M
T =
(I/I
S
)
α
- 1
Where
I – Fault current
I
S
– Setting current
T
M
– Time Multiplier Setting
SI3
K = 0.14
α
= 0.02
SI1
K = 0.0613
α
= 0.02
VI
K = 13.5
α
= 1.0
EI
K = 80.0
α
= 2.0
LT1
K = 120.0
α
= 1.0
6.6. Accuracy
Starter
104% of setting
±
4%
Reset
≥
94% of setting
Repeatability
±
1%
IDMTL Operate Time
±
5% or
±
35 m.sec
DTL Operate Time
±
1% or
±
35 m.sec.
6.7. Output Contacts
6.7.1. T
HE RELAY HAS
5
OUTPUT RELAYS
1.
Common trip / alarm relay
2 N/O
2.
Common Starter
1 C/O
3.
Earth Fault operated
1 N/O
4.
Low set operated
1 N/O
