Auxiliary Energising Quantities - Siemens 7sg15 microtapp Operation Manual

Nt
pf Initial Assumed System Power Factor
2.5 Coupling
The coupling level is entered as the nameplate impedance of the transformer. If the coupling is set other than
zero then the transformers' taps will not drift apart. Over time the transformers will tend to drift together. At the
correct setting the transformers will minimise circulating current quickly but will not result in hunting.
Coupling
2.6 Frequency Load Control
The MicroTAPP will act to prevent frequency reduction by voltage reduction if appropriate by predicting the likely
effect. The settings and accuracies are not yet defined.
2.7 Monitoring and Guard Levels
The MicroTAPP will prevent tap-changer runaway and out-of-limit tapping as follows:-
Overcurrent Level
Overvoltage Level
Undervoltage Level
N.P.S. Level

3. Auxiliary energising quantities

3.1 Auxiliary Power Supply
Four versions of power supply will be available.
Nominal
30 V DC
48, 110, V DC
220 V DC
110 V AC
3.2 Auxiliary Supply Burden
Quiescent
Maximum
©2010 Siemens Protection Devices Limited
No. of transformers
7SG15 MicroTAPP Performance Specification
1 to 16 step 1
0.85 to 1.0 step 0.01 leading and lagging
5 to 50% step 0.1%
100% to 200% step 1%
95% to 120% step 1%
80% to 105% step 1%
10%
Operating Range
24 to 37.5 V DC
37.5 to 137.5 V DC
175 to 290 V DC
82.5 to 137.5 V AC RMS
17W
20W
Chapter 2 Page 4 of 8
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