Voltage of 3 Phase power Cancel The title field is required!

1. Justin Murray

   

   0 posts
   
   4/21/2016 3:04 PM

   We recently had a VFD drive go out. Our pump tech recommended that we get our power company to install a recorder to see if they are having any spikes in the lines. This was due to voltage readings being 498,501,501 on all three legs. He says that this is high and 503 would be max, so we have little room for error and voltage could be weakening the drive. Power company says that they are within their 480 voltage range, 506 is their max. Is this normal with all power companies? Anyone have experience dealing with this?

   
   
   
   
2. Michael Kriz

   

   0 posts
   
   4/21/2016 4:04 PM

   I've contacted our power company before and found them quite helpful...All one has to do is ask. Keep in mind when working with VFD's is have the power company appraise you of neighbors power use in your three phase leg, as THEY may cause power fluctuations.

   
   
   
   
3. Andy Jorgensen

   

   1 posts
   
   4/22/2016 1:04 PM

   We have a pump that is on the dead end of an overhead line. We have always read high, up in the 515 range. Power company has been out numerous times and said this is perfectly normal. In the 8 years this Flowtronix system has been in, we have not had any issues other than some blown fuses, which is pretty normal for Florida.

   
   
   
   
4. Justin Murray

   

   0 posts
   
   4/23/2016 9:04 AM

   Andy Jorgensen said: We have a pump that is on the dead end of an overhead line. We have always read high, up in the 515 range. Power company has been out numerous times and said this is perfectly normal. In the 8 years this Flowtronix system has been in, we have not had any issues other than some blown fuses, which is pretty normal for Florida.

   
   
   Sounds like us. Transformer is fed from underground and goes up to a end of the line overhead thats maybe 400'-500'. This pump is 30' across the road from transformer with another pump fed from transformer about 40'(it also has higher voltage). The overhead runs to a sewage treatment ponds, which I am not sure has any three phase, maybe 240.
   
   The VFD that failed, was 5 years old and seemed pre-mature to fail. Looking at what could have attributed to the failure.

   
   
   
   
5. Andy Jorgensen

   

   1 posts
   
   4/25/2016 5:04 AM

   Justin Murray said:

   Andy Jorgensen said: We have a pump that is on the dead end of an overhead line. We have always read high, up in the 515 range. Power company has been out numerous times and said this is perfectly normal. In the 8 years this Flowtronix system has been in, we have not had any issues other than some blown fuses, which is pretty normal for Florida.

   
   
   Sounds like us. Transformer is fed from underground and goes up to a end of the line overhead thats maybe 400'-500'. This pump is 30' across the road from transformer with another pump fed from transformer about 40'(it also has higher voltage). The overhead runs to a sewage treatment ponds, which I am not sure has any three phase, maybe 240.
   
   The VFD that failed, was 5 years old and seemed pre-mature to fail. Looking at what could have attributed to the failure.

   
   
   I would say that is premature also. I replaced a VFD last summer on a 200hp motor that was 13 years old. I thought that was premature also, but I also contributed it to the heat exchanger had a hole in it a few years back and was blowing water all over the VFD. This was on another pump that hasn't had overly high voltage.