If it is a core clamping issue or a windings clamping issue, do you know if the clamping system on the windings has some sort of a hydraulic compression system? The coil stack column may have shrunk due to degradation and now is loose. Helpful if we know the age of the transformer and whether...
When the electrical engineer designs the transformer coil windings assembly, the physical design is for the wind assembly not to fly apart when a fault goes through the system. For axial loadings of the assembly, he provides a force value that the tie rods must resist - say 300,000 lbs. This...
Raj6:
I am the EOR on a number of tall flagpoles.
https://en.wikipedia.org/wiki/Aqaba_Flagpole
Your latest summary of the criteria required for the design is very good and is what I used on my “monster” poles as these flagpoles were initially called. Today the highest flag pole is the Cairo...
Once before I said some of these things - but my introduction to big numbers for multiplication and division was a about a 3" thick logarithm book that required looking up large numbers and just adding them together and then getting the result from consulting the book. (1961) Remember putting...
IEEE 693 concerns the seismic design of substations including transformers. The California PUC requires that transformers are able to operate during an earthquake and continue operation. The document does not consider degradation of the insulation and what condition the insulation is when the...
Could you hold the approval until the special solution is provided to you for approval as per the contract? I have had the concrete trucks sent away because the geotech and I were having an argument. Can get messy.
Dik: That's the point. What is the maximum variation? The coefficient of expansion of concrete and steel are different and the concrete value is probably not what is in the back of the steel manual. Take the maximum differences in the maximum possible coefficient of expansion of concrete and...
Should also check the thermal stresses. Might have to let one end slide and the other end be an anchor. The COTE of the concrete is unknown because you probably don't know which quarry the aggregate came from. This is currently a contentious discussion concerning transformers and their...
We started with Visacalc. It ran on a Radio Shack Model II. Later we moved over to Lotus 123. Have many files in WK1. Can open with Excel and Libre and save to Excel. The macros don't work. Have about 200 templates, many that were "production" templates, that is they would do 7 problems per...
Just sister on each side without going to the support. Make sure you have enough fasteners to transfer the end shear to the original joist and check the main joist for adequate shear capacity.
It depends where in the country the cable tray is. Does your contract provide a thickness? I've worked with ice from 1/2" to 5". Had one project in North Dakota where the BR said 1/2" and the local building department said 3". I used the 3" and was chastised by the BR plan checker. But I...
In addition: 2022 NYC building code: Basic garage load is 40 psf with a concentrated load of 3000 lbs on a 4.5 x 4.5 inch square area. Ground snow load is 25 psf and the ice load references ASCE 7. Many of the NY codes are web accessible.
Per page 19 of the New York City 1922 and 1929 building codes: Floor Loads: "120 psf for any other purpose...." Roof loads are 40 psf. Could not find a reference to combined roof load (which can be snow and ice) and the 120 psf floor load.
I don't understand how the last few responses have missed the previous graphic that showed a 120 psf live load. To me, a 40 psf load is typically for a residence. Also there is a factor of safety built into the design analysis - even in 1927 or 28 - but I'll have to check my dad's old codes for...
FaceEngrPE: Your building inspector is your last line of defense! Hiring your own inspector is really a good recommendation. I have suggested that to clients years ago. But good inspectors have called the EOR and saved a lot of grief. In LA an inspector called me about a 6 foot diameter...
From the manufacturer's web page:
"Inspection after Snug Tightening
Perform routine observation of the snug tightening process to verify proper techniques are followed as described in Step 1: Snug Tightening
Verify that the plies in the connection are in firm contact.
Verify that the...
