Hi everybody!
Thanks so much for your answers.They were all helpful.I found out that the whole building is ungrounded...this building was built in the late 50's and it never got grounded.Now I am understanding why the drives were faulting on high DC link voltage,because the voltage across the...
Hi Opmgr1
Iam sorry I dont have this information.I just dont know,I was the technician that was troubleshooting on the VFDs and I know our equipment has to have a wye ( star) connection on the secondary side with the neutral connected to ground for the VFDs to operate safe..I guess if you...
Hi DPC
Well as far as I remember they were normal.
L1-L2= 485V
L1-L3= 486V
L2-L3 = 485V
Ya doesnt it seem like the L3 leg is grounded since it is 55 V ?.Thanks
Hi Scotty
Thnaks for your reply.Yes you are right.I told the customer to not run the VFDs until they had solved this grounding problem due to damage.What do you mean by corner grounding system?.I was thinking about putting on input chokes but since there were 20 VFDs that would be expensive and...
I was at a customers site and I was troubleshooting on the VFDs ( Variable Frequency Drives) AC of course.It was tripping out on high DC link voltage...anyway that not the issue.I measured the following on the motor.
L1-ground = 440 V AC
L2- ground = 440 V AC
L3- ground = 55 V AC
I went to the...
