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APU 311k
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| DEVICE FOR AUTOMATIC THREE
- POLE RECLOSING |
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| Application |
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The device for three-pole automatic reclosing APU 311K is desingned primarily
for application in medium voltage networks in which overcurrent protection
is applied.
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| Description |
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APU 311 K is an independant device of the Automatic Control
System for Transformer Stations SAUT. Like the outher devices of the SAUT
system, APU 311 K is all solid state (static relay construction), exept
for the output electromechanical relay.
The information necessary for the functioning of the device is recived
from the overcurrent protection (instantaneoud and time lag contacts)
and from the CB signalling circuits. The functioning of the device is
determined by the chosen mode of operation.
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| Modes of operation |
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- only fast reclosing cycle (F)
- only slow reclosing cycle (S)
- combined fast+slow reclosing cycle (F+S)
- device out of operation (0) |
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| Fast reclosing cycle (F) |
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The activation of the instantaneous member of the overcurrent protection
causes tripping of the CB and activates the fast reclosing cycle. After
the no voltage interval (tf = 0,1 to 1,6 s) has elapsed, the APU device
gives the command for reclosing the CB and, at the same time, activates
the temporarily blocked condition which lasts 10 s. I n case teh protection
operates again (time delayed member) within ghe duration of the temporarily
blocked condition (i.e. whithin 10s of the reclosing) the APU device will
become permanently blocked, the CB will remain permanently open and can
then be closed only manually.
After the elimination of the fault the CB is closed manually, if the overcurrent
protection does not operate whithin 10 s of the manual closing the APU
device is ready for operation, as is the case after a successful reclosing.
Should the protection operate whithin these 10 s the APU device again
becomes permanently blocked.
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| Slow reclosing cycle (S) |
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The operating sequence of the slow reclosing cycle is the same as that
of the previous fast reclosing cycle. The di- fference is in the duration
of the no voltage interval (ts = 30 to 180 s) and the activating member
of the APU device, which is only the time delayed contact of the overcurrent
protection.
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| Combined fast + slow reclosing
cycle (F+S) |
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| The operation of the instantaneous member of
the overcurrent protection causes tripping of the CB and activates the fast
reclosing cycle. After the adjusted no voltage interval has elapsed, the
APU device gives the command for reclosing the CB. Should the protection
(time delayed contact) operate whithin 10 s the reclosing, the CB is again
tripped and the slow reclosing cycle is activated. After the ts no voltage
interval has elapsed, the device gives the command for closing the CB. If
in the meantime the fault is cleared, the reclosing was successful and after
the temporarily blocked condition has elapsed, the APU device is ready for
a new cycle of operation. If the fault was not cleared and the protection
(time delayed member) again tripps the CB, the APU device becomes permanently
blocked. Deblocking is effected in the same way as in the case of the fast
reclosing cycle.
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| Out of operation (O) |
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| In this state the APU device is out of operation
so that only the overcurrent protection is effective. |
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| Characteristics |
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The device for automatic reclosure is all static
construction (integrated circuits and discreet components) so that practicly
unlimited life and high accuracy and stability of characteristics is achived.
The electronic structure is, at the input by means of reed relays, and at
the output by means of the auxiliary electromechanical relay of high breaking
capacity, galvanicaIy isolated from the CB signalling and power circuits.
Thus, eventualy induced transients from the power circuits are greatly suppressed.
Should the CB be opened manually this signal permanently blocks the APU
device and does not permit automatic reclosure.
The no voltage intervals of the fast reclosing cycle tf = 0, 1 to 1,6 s
and the slow reclosing cycle ts = 30 to 180 s are independantly adjustable
in steps of tf -0, 1 s and ts -10s
The choice of the mode of operation and no voltage interval adjustments
are achived by means of plugs on the front platB , under the glassed part
of the cover ;
In addition to the contacts for two pole closing of the CB (K5 -K6, K7 -K8)
there exists a contact for signalling of the permenently blocked condition
(K13 -K15). The device is supplied whith a four digit counter of all reclosures.
The APU 311 K device is packed in a case the dimensions of which are shown
on figure 2.
Figure 1 represents the block diagram and external connections of the APU
311 K.
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| SPECIFICATION |
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Mode of operation
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fast (F), slow (S), fast + slow (F+S), out of operation
(0)
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| No voltage interval settings |
tf=0,1+1,6s in steps of 0,1s
ts=30+180s in steps of 10s
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Accuracy
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tf 50% or 10 ms
ts 10%
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Duration of signal for CB
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0,3 s
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| Duration of temporarily blocked condition |
10 s
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| Counter of all reclosures |
4 digits
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| Output relay contact ratings |
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| maximum voltage |
250V
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| Continuous current |
5A
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| Current at make |
10 A
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| breaking capacity with AC |
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cos=1
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1000 VA
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| with D.C. L/R=40 ms |
20 W
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| Stabilized auxiliary supply voltage |
110V=, 220V= -15%, +10%
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| Auxiliary supply circuit |
130 mA
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| Ambient temperature range |
-5oC to + 40oC
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| Test voltage |
2000V, 50 Hz, 1 min.
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| Dimensions |
as on fig. 2
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For all inquiries please contact the manufacturer.
Subject to change without prior notice.
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