All, to further add to my question. On Cooper Eaton online fuse program, it also gives me VLN rated primary fuses for Wye Wye and VLL fuses for Delta-Wye.
Not sure why for Wye-Wye you only need VLN rated fuses, how about internal phase to phase short circuit scenarios? Hopefully someone can...
All,
I'm working on a project where the client has already purchased two 33kV/480V Wye-Wye transformers, one at 1.5MVA the other at 1MVA. Both Wye neutrals are solidly grounded.
These transformers come with current limiting, primary fuses mounted within the transformer's cable box enclosure...
Just across the frame.
We didn't have the opportunity to investigate further. Just a weird but interesting problem. Vendor took the unit back today. Wanted to post it here if anyone seen something similar.
All,
Unusual problem that I can't explain, looking for some help:
We have a 480V, 3phase, 2MW resistor load bank for testing generators. If we megger the phases with respect to the frame, with the unit's frame not bonded, we get high MegaOhms on all phases. If we then bond the frame, and...
At a mine site, runs along a roadside. Flat terrain, in semi-arid environment with easy access. In mid-Southern USA, no Florida swamps. Double circuit, 795MCM ACSR, strung on both sides of steel lattice structure. Removal of structure and conductors. Foundation can stay, however, possible to...
I am trying to find a unit cost for decommissioning and removing of O/H transmission lines. 2016 PG&E Final Generator Interconnection Unit Cost Guide has the following:
Double Circuit (per mile, $x1000)
69kV = 420
115kV = 420
230kV = 650
Those published values seems high for removal of lines...
We are designing a 480V solidly grounded system for an industrial mine located in the Southern USA, where the climate is mild and the area will be designed with a solid industrial ground grid with multiple ground rods. Customer has requested that all 480V branch circuit feeder (15A CB and...
Hi Waross,
Thanks for the reply. The run will be 305m. I simulated the circuit in PSIM and I can live with the % of unequal current sharing. This will not be an issue. The question in regards to code violate under the CEC.
The CEC states for parallel runs:
a) free of splices throughout the...
At a site in Canada, we have a 5kv feeder that has four 3c-#500 MCM, shielded, Aluminum armoured, 5kV, 100% cables running in parallel. The run length is 350m. One of the phases on a cable failed and the client wants to replace it. They already have onsite a 400m reel of 3c-#500MCM, shielded...
Curiosity question: for PT primary fuses, say 4160V, current limiting, ferrule mounting similar to the fuses shown in the following specification sheet: Link
I noticed that when I measure the fuse resistance with an ohm meter I usually get around 30ohms for a good, non-blown fuse. For all other...
Thanks Stevenal,
My original post was a question about isolating the arrestor from a switch mat bonded to a ground grid to avoid step-touch potentials. I was focused on this topic that I did not realize you were discussing the fact that the arrestor's terminal leads also includes the ground...
Thanks for responding Stevenal, but you misunderstood the question.
The arrestors are located on top of the power pole and the 69kV EPR cable's termination is connected to the arrestor's line side terminal as close as physically possible. The arrestor's ground lug is connected directly to a...
Hello,
We are installing a 69kV EPR incoming service cable from O/H lines to feed our plant. At the O/H power pole structure there is a 3 phase disconnect switch gang operated by a lever handle at ground level. The power pole is wood and sits in a steel pile. There are three ground rods, a #4/0...
Venture here:
http://www.eaton.com/Electrical/Consultants/ConsultingApplicationGuide/idcplg?IdcService=GET_FILE&RevisionSelectionMethod=LatestReleased&Rendition=Primary&dDocName=TB08104003E]Eaton Info[/url]
And go to page 105 in the pdf.
