7SG15 MicroTAPP Description of Operation
©2013 Siemens Protection Devices Limited
Chapter 1 Page 26 of 38
Locked Out
The Relay has Locked Out.
V out of band
The voltage is outside the Dead Band but the Relay is under Manual control
and so cannot correct it automatically.
V very low
The voltage is below 80% of the nominal Primary Voltage.
No voltage
The voltage is below 20% of the nominal Primary Voltage. This will reset only
once the voltage has returned to 70% of its nominal level.
TPI fault
Dead-reckoning Error detected or Tap Position is 0. [MicroTAPP 102 only]
Remote VT fuse blown
VT / VT Fuse failure reported over the MPPC
Switched to TAPP mode
Control mode switched from Circ. Current to TAPP due to MPPC or remote
VT / VT Fuse failure
The complete range of controls and menu functions are detailed in the SETTINGS AND DISPLAY section of this
document.
8.3 Serial communications port
A 25-pin isolated RS-232 is provided for access to the relay’s stored data and settings. The PC or laptop
computer used should be capable of driving the port with at least 7mA at 7V.