Frequently Asked Questions for PowerWatch Voltage Disturbance Recorders
To eliminate this issue, the PowerWatch VDR must be cleared of data at least once every four years.
PowerWatch is half cycle integrated so it synchronizes itself to the consecutive positive and negative zero voltage crossings of the sinusoidal AC line signal. If the AC waveform is so distorted or noisy that multiple zero crossings are detected, the PowerWatch reports loss of synchronization. For 60 Hz, zero crossings should occur regularly every 8.33 msec. For 50Hz, zero crossings should occur regularly every 10 msec.
There are two possibilities:
The first, most likely possibility, is that PowerWatch has detected an anomaly in the AC source that is beyond the scope of PowerWatch to determine. EventReader software displays an error when it reads an undefined code and it simply cannot determine what triggered the event. The event is meaningless for analysis purposes and can simply be ignored.
Second is that PowerWatch is malfunctioning. This can be verified by having the PowerWatch monitor a good known AC source to see if the errors show up again. If the errors repeat on a clean AC source, or the maximum of 4000 events are logged in a short period of time, the logger is likely malfunctioning and needs to be sent in for service.
Example: Error 152
These errors will occur when PowerWatch encounters an event that it cannot interpret as a surge, sag, impulse, outage or frequency event. If these records were masked, there would be no explanation for events missing when the recorder is full.
More recent versions of PowerWatch Software (version 1.29a and above) and all versions of EventReader Software will not allow you to download data from the PowerWatch unless it is plugged into a power source. Click here for more details.