480V wye or delta systems are the most common Low Voltage in industrial settings. 208V or 240V systems are mostly light industrial loads. 208V systems are normally used in offices, schools, ect.
NOTE: Motor nameplate voltage is listed as 230V nominal for 240V systems. And 460V nominal is listed...
podobing,
Check the arc suppression of the arc chute for the contactor. If in doesn't an arc chute then that is your problem. The arc vaporizes the tips (contacts) and after "n" amount of breaking the load operations the tips will be worn to not able to work correctly. Also misalignment of the...
When I design a cable tray system, I always use a grounded bare copper cable EGC (sized for the largest oc device). Mounted by cable tray grd support clamps on the bottom side flanges (either inside or outside). This is to allow for the joint splice plates to be able to move for expansion and...
1Millwright,
Is this your first hot strip mill? I spent 35+ years working for 2 steel mill companies as an EE, with a total of 11 hot rolling mills, plus EMS melt shop, and finishing mills.
You my have a 3 wire delta system with a small zig-zag transformer to develop a neutral point. The neutral...
I don't know your location in the USA, but I bet you that Bechtel has jobs within 250 miles of you. They design, built anything, anywhere. The old saying is "if you want something built and have the money, Bechtel will built it". A few years ago Bechtel had most likely built 75% of all Power...
THRILLHO,
Do you have any electrical work experience? I started as an electrician, at the age of 16 in the summers and I put myself through college as electrician. In fact I made more money as an union journeymen electrician, than a EE for about 3 years in 1960's.
What about a maintenance...
I read the question wrong, or what I wanted it to read.[ponder] MY MISTAKE
What I stated is true, but for coils at every other pole or tower for the expansion/contraction. On long spans required vibration dampers. The owners of the lines with the coils would keep an eye on them for about 2...
Paul
In the very early 1970's I worked for an large electrical contractor in central WI. He had several line construction crews and did a lot of work in U.P., N. WI., and iron mines in MN. When I was first reading of the spec's for on a lot of the jobs that could only be done in the winter...
rmore
Is the new 13.8kV feeder incoming out of the room anywhere near your 480V controllers outputs outside of the room. Since it's a new install, the cable(s) shield maybe damaged.
An old lineman trick is to take a portable AM radio an follow the new 13.8kV feeder incoming from the room to is...
Need more info. Is the purge system used for keeping vapor out of the enclosure you only need an inlet with a pressure regulator. If purge system is for vapor control and enclosure cooling most likely need inlet and outlet lines. I never seen purge systems on the top of the enclosure, mostly on...
I had the same problem. I was told not to spend any money on double ended 2400vAC 1600Amp switchgear, that was a 1930 vintage. Finally water entered into the swgr starting a fire on an inline CT. A temporary fix was pain ordinary roofing tar and made small hip roof out of plywood and covered...
I still believe that they are cables, maybe some is painted. If it is conduit, it would be impossible to pull wire. Also most of the "cables" have a very tight (small) radius 90o which is impossible for conduit.
After looking at the bottom photo, top right that maybe conduit using some type of...
All most all power switching breakers are DC. All substations use DC via batteries for switching and protective relays.
In nearly 45 years I have seen one failed DC system. That was 48vdc system in a very small substation and batteries where bone dry also a small tree was growing in a breaker...
As Bill stated first check with AHJ. The only NEC problem that I see is changing wire size without OCP at the junction of 500kcm Al to 350kcm Cu. The amperage is about the same, but the difference in the cable size. I would think best thing to do, use 500kcm Cu instead of the 350kcm Cu. That...
I believe that 5kV & 15kV load break switches are the seem switch but the fuses are, of course different. Square D calls that switch HVL (high voltage load).
I do not have the Sq D Digest with me now, but I remember that bays are about 3'+ wide.
Hope this helps and good luck,
Dave
