High Capacity Amperage Measurement
We had a situation a few months back where we needed to monitor amperage on a grocery store panel over a period of time. The trouble was, we needed data logging capability as well as accurate measurement at 600+ amps.
Finding an all in one solution proved to be quite expensive. Luckily my friend Jim Bergmann happens to own an instrument company (Redfish Instruments) and he had a simple solution.
Use the data logging capability of the Redfish multimeter with a Fluke I800 amperage to mA (milliamp) clamp to get the job done.
This particular clamp can be used with any good quality meter that reads in the milliamp range (not to be confused with uA which is microamps often used for testing flame rectification).
Like shown below, for this clamp you connect the meter leads to the correct jacks and select the mA scale. In this particular case 1mA = 1A so the image below is showing a 320 amp measurement.
There are other accessory clamps that use the mV (Millivolt) scale rather than mA like the Redfish IDVM333 shown below.
With this clamp the output scale can be adjusted with the selector on the clamp to either 10mV AC or 1mV AC.
Again you need to make sure the leads are in the right spots based on the type of clamp reading and make sure to get in in the right scale, but once you understand how to it, it’s surprisingly simple and you can use a wide variety of clamps and meters.
Bryan Orr is a lifelong learner, proud technician and advocate for the HVAC/R Trade