From time to time, we receive technical support calls and emails about whether our current sensors are compatible with ECM loads. With many motorized loads utilizing an ECM, this is a valid question. Not too long ago this question led our engineering team to conduct our own research and testing, and we determined that our RIB® current sensors could indeed sense an ECM load being activated. That research and testing was one of my responsibilities early on when I began my job here at Functional Devices, and those results are what I would like to share for today’s Tech Tuesday post.
As stated in the above link, our current sensors will operate with an ECM load. Page 2 of the document provides a list of current sensor models proven to operate as intended when used with an ECM load. From personal experience, I would say that if you are weary of using one of our RIB® current sensors, first try an “adjustable” model. Using an adjustable model may make it easier to prevent the current sensor from giving a false-positive signal of the load status.
The testing results do not hold true for “variable frequency drive” (VFD) controlled loads. The frequency of the load wire being monitored needs to be stable, as our current sensors cannot accurately read a varying frequency. An inaccurate current reading could produce an incorrect status feedback.
Want to double check if a current sensor will operate in your particular situation? Feel free to email us or give us a call! Be sure to have the specifications of the load ready to share, so that we may give the most accurate and confident suggestion possible.