Power-line load monitoring

Power-line load monitoring using LogicMachine Reactor #

Task #

How to make a cost-effective power-line current monitor solution based on LogicMachine Reactor?

Connect current sensor with analog output to Reactor’s Analog input #

We recommend Veris Industries H923 split-core current sensor which provides a 0-10V output signal which is proportional to the current flow.

Or there are even more cost-effective 0-5V solutions available from YHCD (~EUR 4/pcs).

Power Veris_H923 Power sct010t

Add Analog input object in Reactor tab of LogicMachine #

Adjust the Multiplier parameter of the analog input based on maximum voltage to current ratio.

Example: if the clamp outputs 10V at 30A the multiplier must be set to 3.

Power analog_input

The measurement is automatically seen in the Reactor and Objects tab.

Power analog_input_mesurement

Power object_load_sensor

Calculating the average #

Event script #

Attach this script to the current value object.

key = 'current'
value = event.getvalue()

storage.exec('rpush', key, value)

Scheduled script #

This script will calculate an average over accumulated values and send the average value to 1/1/1.

Average value can be used to create a more accurate trend log.

key = 'current'
values = storage.exec('lrange', key, 0, -1)

if type(values) == 'table' and #values > 0 then
  sum = 0

  for _, value in ipairs(values) do
    sum = sum + tonumber(value) or 0

  -- remove read entries from the list
  storage.exec('ltrim', key, #values, -1)

  avg = sum / #values

For multiple current clamps use a different storage key in both scripts.