Thanks palletjack. I will take your advice. Fortunately I have motor protector that detects the voltage drop due to a locked rotor and shuts the soft start off. Save my bacon several times.
Well I guess I should have opened the door. I was sure the rating was in kW-oops. Here is the data plate behind the green door. I still am questioning the 7 amp K fuse on the dist line that blows every few years. Costly to bring out a lineman. Hence my wish to change the fuse links to 10 amp...
I have some nuisance tripping of distribution line fuse links feeding a pad mount transformer. I suspect the fuse is not appropriate for the transformer. The transformer is rated at 45 kW, primary voltage is 4800, secondary is 480. The load is a 40hp motor with a soft start/stop so the inrush...
Contact is a serious analysis. I suggest that the problem lies either in the load application or that the elements are distorting beyond ansys's capability. If the latter is true you need to use a explicit analysis code for the solution as abaqus or use ansys's explicit code. If the former is...
reply to jbartos...
Do you have an idea or a "suitable' software? Possibly I could get a "tria;" version.
you may contact me at my domain email.
max@engsrv.com
Re jbartos,
The question is, assuming that the house is drawing 1 kw through the step up transformer (480 to 4800) and then I start the well motor (100 amp@ 240) the initial in rush current may be as high as 300 amps or more. Will the 'step up' transformer be able to respond immediately or...
This forum has been very helpful. For reference, Im planning on stepping up 480 3 ph to 4800 for 4500 ft and then back down to 240 for submersible 35 hp pumps. Additionally I want to pull house power at the terminus. Someone mentioned TRANSIENTS.
This got me worried that the house will be...
Charles, To be a little more clear, imagine a correctly preloaded bolted joint. The faces are in compression and the fasteners are in tension...springs. What do you think the nat freq of that joint is? Can be calculated by hand but its likely higher that any system resonances of interest...
Typically in FEA the dynamic model is very coarse. All that you need to simulate is the mass and stiffness of the system. If you think that the bolts and holes affect the dynamics significantly use engineering judgement to either fill them or not. assemblies have difficulty as usually the...
Contact is non linear and Im still amazed at how many engineers think that it is a slam dunk. Make sure that you have the contacts on the correct surface and targets on the correct surface. (read ALL of the help on contact!)Reversing these can often turn a horrible pbm into an easy one. Also try...
I assume that you would be using contact elements to simulate the intereference. I have done some work that indicates that the stresses resulting from this type of analyis is highly dependant on type of element and mesh density. Even with a high mesh density the results do not appear to be...
In discussions with the county engineer, he suggested that I could design my line myself and stamp it. P.E.ME ...as long as the calcs were reasonable. I may be over my head here but his big issue seemed to be the the voltage loss in ACSR 2 over a 9000 foot run at 4160 3 phase. The load is 26...
Im having a tough time finding a source for power poles. 40ft. Internet search doesnt turn up much for a "power pole" querie. Im in So CAl. I have located some used poles but am concerned about grading them. Is there a standard for grading so I dont buy pig in a poke?
Max PE ME
Thanks all for your helpful comments. My contractor has a good supply of used 4800V primary transformers. Additonally the Edison planner suggested that the disconnect box would be very expensive if I did high voltage metering. The cheap xformers imply doing the 3000ft run at 4800 but the high...
