Normally, the WattNode® Pulse meter generates a 4 Hz full-scale pulse frequency. In other words, at nominal full-scale power (nominal line Vac, nominal rated CT current, power factor = 1.0), the meter will generate four pulses per second.
There are a few reasons you might want to select different full-scale pulse frequencies:
- You want a nicely scaled output, like 10 pulses per kilowatt-hour or 1 kWh per pulse. The best way to achieve this is with Option Kh.
- You are connecting the pulse output to an LCDA-P or LCDA-EP and want to set the full-scale pulse frequency to 20 Hz to improve the display of power (faster updates, can display a wider range of powers). See LCDA-P Power Display (AN-116).pdf and LCDA-EP Energy & Power Display (AN-115).
- You need a very high pulse frequency (or pulse count) for maximum measurement resolution. The normal WattNode Pulse meter with bidirectional outputs can generate full-scale pulse frequencies up to 600 Hz nominal (900 Hz overrange). The WattNode Pulse meter with options P3, PV, and DPO can generate full-scale pulse frequencies up to 150 Hz nominal (200 Hz overrange). Before ordering a WattNode Pulse meter with a high pulse frequency, check that your monitoring equipment (data logger) can handle the desired frequency. Many data loggers have very limited maximum frequencies.
- You need a lower than normal pulse frequency because your data logger or monitoring device cannot handle the normal 4 Hz output, or a lower frequency saves battery energy.
To compute scale factors with custom pulse frequencies, see the full WattNode Pulse manual for equations.
- Download Manual (PDF)
There are two ways to order Option Hz.
Single Frequency, Hz=xxx
This is most common and sets all active pulse output channels to the same full-scale pulse frequency.
- Example: WNB-3Y-208-P Opt Hz=20. This sets all pulse output channels (P1 and P2 in this case) to 20 Hz full-scale.
- Example: WNB-3Y-208-P Opt P3,Hz=0.5. This sets all pulse output channels (P1, P2, and P3) to 0.5 Hz full-scale (one pulse every two seconds).
Multiple Frequencies, Hz=xxx/yyy/zzz
This sets each pulse output channel to a custom full-scale pulse frequency.
- Example: WNB-3Y-208-P Opt PV, Hz=20/33.33/40. This sets the P1 channel to 20 Hz, P2 channel to 33.33 Hz, and the P3 channel to 40 Hz.
- Example: WNB-3Y-208-P Opt P3, Hz=50/100/150. This sets the P1 channel to 50 Hz, P2 channel to 100 Hz, and the P3 channel to 150 Hz.