CHAPTER 5: SETTINGS
SYSTEM SETUP
L90 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
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5
LOCAL GPS TROUBLE
— This signal is On when any of the following conditions are present:
•
The best clock selector (BCS) selection is none or SNTP
•
The BCS selection is IRIG-B and the
IRIG-B SIGNAL TYPE
setting is Amplitude Modulated
•
The RTC and/or the synchrophasor clock are not synchronized to the selected synchronizing source. This can possibly
occur on power-up, when transferring between sources, and when the selected source's holdover timer times out.
•
The quality bits in the messages from a PTP source used for synchronizing indicate worst-case error greater than 250
µs, or accuracy less than 250 µs, or unknown accuracy/error (that is, not locked to an international time standard).
Apply two security counts (2 seconds) to both set and reset of this operand when change is based on accuracy. There
is no corresponding quality test for IRIG-B sources here.