I am quite surprised that any engineer - mechanical, chemical, or industrial - working in a processing plant does not have knowledge or experience in using what we old timers used over 60 years ago. The instrument was (and still is) called an Amprobe. Go to:
http://www.amprobe.c...ts/clamp-meters
and get a first hand look at what they look like and get one of their catalogs.
You do not need an electrical engineer to use this instrument nor to calculate the motor's electrical load. Read the article that Bobby Strain recommends. You must understand how alternating electrical current works and how it is applied and measured - especially the existence and workings of a Power Factor. I believe that is why Bobby has pointed out this fine article. We old time Chemical Engineers had to take Electrical Engineering courses and labs where we learned this stuff. I took two courses before senior year and used my first amprobe in my first job out of college. I thought every ChE knew this stuff. I certainly would expect them to.
As a plant production manager I always expected my project and production engineers to use this instrument and always have access to one.