Gt:K-45376
Both the Hi- Seismic target and sea l -in unit and the Hi- Seismic instantaneous unit have the letters "Hi
G" mo l ded into their target block to distinguish them as Hi-Seismic units . Seismic fragility l eve l exceeds
peak axia l acceleration of l Og's ( 4g Z PA ) when tested using a biaxia l mul ti -frequency input motion to pro
duce a Required Response Spectra ( RRS ) in accordance with the I EEE Proposed Guide for Seismic Testing of
Relays, P501, May,
1977.
RAT INGS
The re l ays are designed for operation in an ambient air temperature from -200C to + 5 5oc .
T I ME OV ERCURRENT UN IT
Range for the time overcurrent unit is shown in Tab l e
1.
TABLE
1
Frequency
Current Range
Relay
( Hertz )
(Amperes )
I FC66A, B& K
50 and 60
2.5 - 7. 5
Avai l ab l e taps for the time overcurrent unit are shown in Table 2.
TABLE 2
Range
Taps Available
(Amperes )
(Amperes )
2 . 5 - 7 . 5
2. 5, 2 . 8, 3 . 0, 3.5, 4.0, 4.5, 5.0, 5.5, 6 . 0, 6.5, 7.5
The one second therma l ratings are listed in Tab l e 3.
TABLE 3
Mode l
Time Overcurrent Unit
One Second Ratin
)
Any Tap
K
(Amperes )
(Amperes
IFC66A,B& K
2. 5-- 7 . 5
350
122 500
Ratings l ess than one second may be ca l cu l ated according to the formu·la I =v' K/T, where T is the time
in seconds that the current f l ows .
The continuous ratings for the time overcurrent unit ar.e shown in Table 4.
TABLE 4
2 . 5 - 7 . 5 Ampere Range Ratings
Mode l
I FC66
Tap
2 . 5
2 . 8
3.0
3 . 5
4 . 0
4 . 5
5.0
5. 5
6 . 0
6 . 5
7.5
Continuous Current
5.0
5.3
5 .5
5 . 8
6 . l
6 . 4
6
. 8
7 . 0
7 . 3
7 . 5
8 .0
H I -SE I SM I C INSTANTANEOUS U N I T
The instantaneous coi l is tapped for operation on either one of two ranges ( H o r
L).
Sel ection of the
high or l ow range is determined by the position of the l ink l ocated on the top of the support structure .
See Figure 2 and Tab l e 5 .
Since the instantaneous unit coi l is in series with the time overcurrent unit coi l , see Tab l es 3,4, 5
1nd
6
to determine the current l imiting e l ement for both continuous and short time ratings .
* indicates revision
5
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