I am wondering if anybody is up on IEEE standards. We have found a that IEEE 422 was rescinded sometime around 1994. We have an engineering firm that is adamant that signal cables are required to be run in Rigid conduit when routing through underground duct banks in a power plant per the 422...
I am dealing with a nuisance tripping problem on a differential protection scheme and am looking for some help in understanding as this is a bit over my head. (We do have an engineer working on the problem as well)
The situation is we have a line up of GE 15KV switchgear with A and B side feeds...
A year an a half ago I installed a cogeneration plant at a hospital. The scope involved combining three separate services into one 4000A 277/480V service and all work associated with a 600KW 277/480V 4W generator that parallels with the local utility. There is a heat exchanger that heats a...
Hello,
A job I did last year suddenly started having problems. It is a 600KW Co Generation unit at a hospital. The operating voltage is 480V. Everything worked fine for months and now it seems to be tripping on a "Neutral Current Fault". I don't have any more detail as I haven't been back to...
I am looking for some input on these pictures. http://www.electrical-contractor.net/Forum/Images/SurgeArrestor-1.jpg
http://www.electrical-contractor.net/Forum/Images/SurgeArrestor-2.jpg
This is the 12KV secondary of one of two step up transformers on a rush project. I did the terminations...
I have an issue on a co-gen project where the controls on the generator are expecting to see open delta connected PT's (480 to 120V) on each side of the generator breaker for synchronizing to the utility. The controls in the switch gear, where we will be pulling the signal from, have this set up...
OK, I have exhausted my resources and am looking for opinions. This is the scenario. I am completing a small prime power generating station with natural gas generators. There is a dispute as to the classification around the in coming gas supply metering area. I asked the question weather or not...
I am doing a small power plant and a ran into a problem yesterday. When terminating the last run from the generators to the paralleling gear we found water ingress in one of the cables. The run is a 4" conduit with 8 350MCM XHHW conductors (+ ground). Operating voltage is 480/277. Part of the...
I thread in another forum has sparked my curiosity. The subject being the practice of utilities transitioning from overhead to underground (66KV) with the insulated (UG)cables entering a steel pole through individual holes. Since there is no mutual canceling of phases with this arrangement is...
I can't seem to find any information on using the shield (tape, wire, uni-shield etc.) in medium voltage cable as the equipment grounding conductor. In installations I have been involved with we always pulled an equipment grounding conductor along with the feeders and grounded the shields at...
