SKM stores its database information in text files divided into 512-byte records. It's easy enough to identify the file and record headers and field terminators, but I can't correlate the actual data to the model; maybe it's a hash. To streamline building a large model, I would like to enter...
I have worked in various environments where the range of expectation ran the gamut:
1. One place where engineers were not allowed or expected to CADD, because they were paid to be engineers, not CADD techs;
2. One place where engineers were expected to do any CADD necessary;
3. One place...
DavidBeach:
If you put a single conductor in each conduit, will you not get severe inductive heating effects, or is that somehow not so with transmission lines?
WEH
I did both FE and PE, starting fourteen years after college. You have to set aside lunch hours and Saturday mornings for working problems.
Get the PPI-2-Pass books and work every problem you have time for, starting with Math 101.
Get a sample exam and work every problem over and over until...
Good eye, MJ. In that case, MattP should provide Company A with price recommendations instead of Company B. It is just like doing an engineering or construction estimate as the designer.
William
I would not see a problem as long as everything is above board and ther is no kickback or anything of the sort from Company B. It makes sense that they would use your expertise in pricing it. The interests not conflicting but complementary.
William
Most plants can be operated without 220 (or 240, whatever you want to call it). You will probably end up with a 45kVA 480 to 208Y/120V three-phase dry-type transformer mounted on a concrete pad on the floor. At 208V, a 30 kVA xf will serve a 100A main breaker, 45kVA will serve a 150A MB.
William
rj:
The advice from this forum seems to be for you to get out of the situation. Your transition from ignorance to enlightenment is obvious as one reads through it, but now that you are no longer ignorant, you can't just wait to see what happens. Make a copy of this discussion--it names names...
With an FLA of 650A, your O/C can be as high as 2000A. The 250% FLA is a maximum value for O/C, but it can be less than that. If you are using soft starts or VFD's, then your protection can be lower. I would look for a way to get three molded-case CB's in those two 1600A cubes.
William
The 1000A GF requirement is for service entrances (230-95). You still need O/C protection and a disconnecting means for each motor.
The disconnect must be at least 115% of the FLA, unless it is rated for the horsepower of the motor. In your case, the disconnect must be either 800A or 525 hp...
There are specialized programs for doing that. I worked for a Defense Contractor A/E that had a full-time spec typist using Specsintact. Try CCB.org.
William
Question somewhat related to the thread:
Does anyone know how those devices work that allow you to touch a metal part of the lamp to turn it on?
ItSmoked:
Where do you live, that you pay $0.26/kWh? Yikes!
William
If your generator cannot handle the starters, then it cannot handle the motors. It is possible that phasor voltage difference between the source and the motor is greater than if the motor is stopped.
Why does it matter whether the coils are held in during a changeover?
Why don't you put a...
The 140A value under discussion is probably the RMS (root-mean-square) value, that is, the effective DC value. From a resistance perspective, there is no difference in heating of the wires, but there would be heating attributable to inductive effects that would not be present in the DC case...
