Power Quality Events

The i-Sense monitor generates different event types:

PQ Event
The i-Sense detects two types of power quality events: RMS Variation events and Waveshape Variation events. An RMS Variation event is triggered by the i-Sense when the voltage on any of the monitored phases rises above an upper threshold (112%), or falls below a lower threshold (87%).

The Waveshape Variation event algorithm continuously compares each data point on the waveform with the moving average of that point over previous 60 Hz cycles. In other words, the algorithm "learns" the voltage waveform and then detects variations from the "learnt" waveform. This algorithm is sensitive to small deviations and allows triggering on waveform deviations that may not cause an RMS Variation event.

Heartbeat Event
Every 12 to 24 hours, the i-Sense collects a sample of the RMS voltage and voltage waveform. This "Heartbeat" event causes the i-Sense to immediately connect to the i-Grid. Heartbeats are useful for verifying that the i-Sense is operating normally. A heartbeat event can be generated at any time by briefly pushing the LED/button on the i-Sense.

Power Up Event
When the i-Sense is first installed, a "Power Up" heartbeat is recorded. A Power Up event will also be recorded following a firmware change.

Voltage Event Detail Page

The page header includes timestamp, duration, IEEE classification and monitor details. You can also export the single event to Excel, XML or PQDIF for further analysis. The minimum/maximum RMS and the worst-case RMS as a % of nominal is displayed for each channel. The first and last 4 cycles of the voltage waveform is recorded. The red cross (+) denotes when the event was detected. The blue cross (+) denotes when the event is declared over and conditions has returned to normal. Longer duration events will be split into separate start and end charts. The RMS voltage is recorded throughout the event. The red cross (+) denotes when the event was detected. The blue cross (+) denotes when the event is declared over and conditions has returned to normal. The maximum resolution is half-cycle. The resolution will decrease for longer duration events.