This has been transcribed from an actual support event
Hi, I have an Elster A1140 meter reading in on PNPSCADA, and on my profile there is a gray patch, and when I go to the event view it says that there was a Phase Failure for about 7 hours, however it doesn't say which phase it was, and the profile doesn't go down at all, so it doesn't seem like the phase was really off?

Yes. You'll also notice that those events start and end exactly on the half hour.
Basically, they were not read from the event log on the meter, but they were embedded in the profile, via some bits that was switched on during that half hour corresponding to the profile half hour returned from the meter when reading profile.
That flag does not come with information of which phase it was, or more time information than just the inherent half hour information of the profile. In PNPSCADA we check the bit in consequtive profile periods, and we log one event at the start of the first profile period in which it appears, and end the event at the end of the last profile period in which the bit appears.
Probably, what it means, is that during the half hour there has been phase failures. We also don't know how many phase failures there were. But since the profile did not go down, it is unlikely that the phase failure lasted for the full period of fase failures (7 hours). Rather there was a period of 7 hours during which multiple phase failures occurred.
Hope that helps!
:-)