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a and are two parameters, suggested the standard, which vary the type slope selected (e.
The PR123/P fitted with two instruments make this thermal memory..
Standard trip curve according IEC 60255-3
There are types curves settable, defined the IEC standard 60255-3 and C. The other characteristics are the same those for thermal memory
"L" (see par.1s .Watchdog for proper connection the trip coil (TC).25xI1.2 Start-up threshold "S"
The start-up function can selected the case where the curve with fixed time selected.9. 2
Page No.2 Protection "
This protection can disabled; can the fixed time (t=k) inverse time (t= k/i2) type.
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..2.2.9.1 Protection "L"
The "L" the only protection that cannot disabled because for self-protection against overloading the relay itself.9..
The function can disabled and setting characteristic the single protection units. This parameter automatically calculated setting
the parameter (required trip time 3xI1). enabled, any anomalies are indicated special alarm message and the "alarm"
LED coming on. the PR120/D-M module installed, this activates the coil opening command (YO), thus opening the CB. The
latter must intended follows:
- Passage the RMS value the maximum current over one single adjustable threshold (0.
NB: Time expressed seconds.1).
The start-up function enables the protection threshold (S, and changed during time interval lasting "ts", starting from "start-up".2.
14.
Otherwise, the trip time will reduced, depending the overload which has occurred and the time that has elapsed.2. enabled, the event the sensors being disconnected Rating Plug error, opening command
is given the being enabled.1 Thermal ory "L"
The thermal memory function can enabled for cable protection.B.
14.9 escription the protection functions
14.1In steps).
V )
NB: Time expressed seconds.
Standard trip curve according IEC 60947-2
Only one type curve settable (t=k/I2) defined the IEC standard 60947-2.2.
Range: 0.10In, 0. the latter case, the trip time given the expression:
100 t,
- t
\2 where where the fault current and I2the protection threshold. based the''TL" parameter defined the trip time the curve (t1) selected
at 1.5);
b parameter introduced SACE increase the number curves with the same slope.2.1. 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.5xI2.
The protection trip time inverse time given the expression:
k f
t where the fault current and I1the protection threshold specified the user.2.9.g.01s.: The thermal memory function can only set the type curve selected the standard one (t=k/I2) (see par.
□ Watchdog for protection Trip..9. This based the
"tS" parameter defined the trip time the curve (t2) selected 1. The types trip curves
settable are divided into two groups according the standard they refer to. for type slope a=1 and k=13.
4.1 Thermal ory "S"
The thermal memory function can enabled for cable protection the case where the curve with inverse time selected.
14.9. 30s, with steps 0. 14.2. 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.
14.2.
Model 2234 Apparatus Scale
L2778
Doc.9.
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.
It the PR123/P release that automatically decides which the two use, according the various situations.1.1. No.
N. 14. new start-up possible
after the current has dropped below this threshold.2.1)
