leitmotif
Member
arroyo said:I'm looking for the correct size CT (current transformer)
I want to install (1) CT to monitor the amps of one leg of a 3 phase 460 volt 125 HP motor with a full load amps of 167. I have an analog ampmeter scaled from 0 - 150 amp, and a CT with a 300 to 5 ratio. , please advice if this will work, or do I need to make some changes.
thank you for your help
Lessee now
You have a motor whose full load is 167 amp.
You have a 300 to 5 CT
You have a meter whose scale is 0 to 150 amp and I ASSUME is set up for a 5 amp input.
Now if I am right then the meter would work BUT it will not read correctly - would only read at one half the actual current.
What I think you need is a 0 to 300 amp meter matched to a 300:5 amp CT. This would actually be better because you would not wrap the needle during starting.
Dan Bentler