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The release trip time certainly 100% the one selected, after interval has passed since the last overload since the last trip.
The protection trip time inverse time given the expression:
9 ,
, where 12ln, where 12ln where the fault current andI1the protection threshold.
Standard trip curve according IEC 60255-3
There are types curves settable, defined the IEC standard 60255-3 and C.
14. The types trip curves
settable are divided into two groups according the standard they refer to.
Standard trip curve according IEC 60947-2
Only one type curve settable (t=k/I2) defined the IEC standard 60947-2.1.
Ith
1
Start Threshold I2
Threshold I2
Start Up
Programmed time ts
• Start-up tim e
The start-up time common all the protections involved.25xI1.9.5);
b parameter introduced SACE increase the number curves with the same slope. based the''TL" parameter defined the trip time the curve (t1) selected
at 1.1).
4.9.
Model 2234 Apparatus Scale
L2778
Doc.9.. 14.1In steps). No. 14. new start-up possible
after the current has dropped below this threshold.1). The first only effective when the release powered (it also records
overloads that have not lasted long enough trip the release), while the second works even when the release not powered, reducing any trip
times the case immediate reclosing and enabled soon the tripped.
□ Watchdog for protection Trip.
It the PR123/P release that automatically decides which the two use, according the various situations.
V )
NB: Time expressed seconds.1 Thermal ory "L"
The thermal memory function can enabled for cable protection.2.1 Protection "L"
The "L" the only protection that cannot disabled because for self-protection against overloading the relay itself. the latter case, the trip time given the expression:
100 t,
- t
\2 where where the fault current and I2the protection threshold. enabled, the event the sensors being disconnected Rating Plug error, opening command
is given the being enabled.
14. The other characteristics are the same those for thermal memory
"L" (see par.9.1.
The PR123/P fitted with two instruments make this thermal memory. the PR120/D-M module installed, this activates the coil opening command (YO), thus opening the CB.
14.2 Start-up threshold "S"
The start-up function can selected the case where the curve with fixed time selected.
14. The
latter must intended follows:
- Passage the RMS value the maximum current over one single adjustable threshold (0.
The function can disabled and setting characteristic the single protection units.9.2.2.2.Watchdog for proper connection the trip coil (TC).
NB: Time expressed seconds.g.
The protection trip time inverse time given the expression:
k f
t where the fault current and I1the protection threshold specified the user.9 escription the protection functions
14. 30s, with steps 0.
The start-up function enables the protection threshold (S, and changed during time interval lasting "ts", starting from "start-up".. enabled, any anomalies are indicated special alarm message and the "alarm"
LED coming on.2.
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.2. 2
Page No..2.1 Thermal ory "S"
The thermal memory function can enabled for cable protection the case where the curve with inverse time selected. for type slope a=1 and k=13.2 Protection "
This protection can disabled; can the fixed time (t=k) inverse time (t= k/i2) type.5xI2.9..2.2.01s. This parameter automatically calculated setting
the parameter (required trip time 3xI1).9.
Range: 0.1s . This based the
"tS" parameter defined the trip time the curve (t2) selected 1.
Otherwise, the trip time will reduced, depending the overload which has occurred and the time that has elapsed.1.
N.10In, 0.
a and are two parameters, suggested the standard, which vary the type slope selected (e.: The thermal memory function can only set the type curve selected the standard one (t=k/I2) (see par.2.B
