TYP E
CONTACT GAP
APPROXI MATELY
.020
I N C H
.24
.22
.20
.18
NEGATIVE SEQUENCE I NPUT
V O LTAGE TO FILTER
.16
(J)
( L I N E TO NEUTRAL BASE )
0
z
. 14
0
u
"'
(J) .12
�
"' . 10
::E
;::
.08
.06
.04
.02
0.5 v.
v.
v.
v.
v .
0
0
5
10
15
20
25
30
35
40
NEGATIVE SEQUENCE AMPERES INPUT TO F I LT E R
184A995
Fig. 6. Time Curve of the Directional Unit (D)
The front spring, in addition to holding the target,
provides restraint for the armature and thus controls
the pickup value of the switch.
C H A R A C T E R I S T I C S
The time characteristics of the time overcurrent
relays are designated by specific numbers as indicat
ed below ( eg. IRQ-8).
T i m e
C h a r a c te r i s t i c s
Short Time
Long Time
Definite Time
Moderately Inverse Time
Inverse Time
Very Inverse Time
Extremely Inverse Time
D e s i g n at i o n
2
5
6
7
8
9
1 1
The relays are available in the following current
ranges:
Time Overcurrent Unit
Range
Tap s
. 5-2.5
2-6
4- 12
0 . 5
0 . 6
0 . 8
1.0
2
2. 5
3
3 . 5
4
5
6
7
1. 5
2.0
2.5
4
5
6
8
10
1 2
REST OF C I RCUIT
MOTE:
--{ SAME
.1.$
TIIAT
AT
CLOSE CS-1 COitTACTS
lEFT
TO TEST OYEICUIIEIT
ALTERIU.TJVE CONNECTI O!'S FOR 5 T0 2. S .uti'ERE U.IIGE
I RJI-5 AND I�Q-6 RH.I.YS
Ult!T (CO)
292B934
Fig.
7.
D iagram of Test Connections for the Circuit Clos ing
Time Overcurrent Unit of the IRQ Relay.
Instantaneous Overcurrent Unit (I)
Range
Tap s
0 . 5- 2 Amps
0 . 5
0. 7 5
1 . 0
1 . 25
1 . 5
2
1-4
1.0
1 . 5
2 . 0
2.5
3 .0
4.0
2-8
2
3
4
5
6
8
4- 16
4
6
8
9
1 2
1 6
10-40
10
15
20
24
30
40
20-80
20
30
40
48
60
80
The tap value is the m1mmum current required to
just close the relay contacts.
The time vs. current characteristics for th e time
overcurrent unit are shown in Figs. 15 to 2 1 . These
characteristics give the contact closing time for the
various time dial settings when the indicated multi
ples of tap value current are applied to the relay.
The time vs. current characteristics for the in
stantaneous overcurrent unit is shown in Fig. 1 3 .
The time v s . current characteristics for the direc
tional unit is shown in Fig. 6.
D i re c t i o n a l U n i t ( D )
The directional unit minimum pick-up is approx
imately 0. 76 volt-ampers ( e . g. 0. 19 volt and 4 am-
5
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