U
User 1.nospam
- Jan 1, 1970
- 0
I saw a new one (to me) yesterday. Trouble shooting an aircompressor
control panel I got strange readings on the incoming line to ground. I had
thought it was a standard 480Y277 service. On one leg to ground I got
242volts.
I thought I was familiar with all the different configs available in the US,
so imagine my surprise when I examined the three xfmrs on the pole and
discovered that they were connected 480 delta and that one of them had a
center tap, which created a neutral, hence the 242 volts. The connections
could have easily been for 240, 4 wire, which is fairly common here, but it
is definitely 480-4wire. The installation is about 10 years old.
I have done electrical work in this area (Kentucky) for 30+ years and this
is a first. So I ask, anyone else ever seen this? What applications does
it have? Is it common anywhere?
Maybe the power company ordered the wrong xfmrs, or got a real deal on a
closeout!
control panel I got strange readings on the incoming line to ground. I had
thought it was a standard 480Y277 service. On one leg to ground I got
242volts.
I thought I was familiar with all the different configs available in the US,
so imagine my surprise when I examined the three xfmrs on the pole and
discovered that they were connected 480 delta and that one of them had a
center tap, which created a neutral, hence the 242 volts. The connections
could have easily been for 240, 4 wire, which is fairly common here, but it
is definitely 480-4wire. The installation is about 10 years old.
I have done electrical work in this area (Kentucky) for 30+ years and this
is a first. So I ask, anyone else ever seen this? What applications does
it have? Is it common anywhere?
Maybe the power company ordered the wrong xfmrs, or got a real deal on a
closeout!