Lets say the main substation feeds a variety of stationary equipment. If so the Low side grouding of that substation can be solidly, ungrounded or resistance grouding. And you have a neutral run from that substation to the isolation substation or you do not have the neutral run.
The isolation...
In the world of surface mining equipment, specifically large electric draglines and power shovels, the older units were MG set (motor generator) powered. And you could observe on the utility source bus, the voltage fluctuation due to the load swings as the dragline went through its motions. A...
In my experience engineering firms will not turn away a job even if they do not have experience in that area. For example, firms that have no medium voltage experience, will not turn away a substation job. If they can't or more often won't get someone who has the expertise, they will wing it...
I think it boils down to this. Low quality contractors and plants with poor configuration management will leave the cables in place. Of course, direct buried needs additional consideration. Jim
In stripping (open pit) and UG ore mines the energy release from a thumper does not matter and a good deal of energy is needed to find a cable fault in MV cables with resistance grounded systems.
In coal mines with the potential for methane gas it could be an issue but I don't believe that I saw...
If you are smart enough, dumb enough or you have enough of a stomach to have stayed with a major company ( chemical, utility, oil and gas etc) for 30 years you could walk away with $2 M 401 K and almost a six figure per year defined benefit pension. A number of people in this group have never...
The worst reason for a female to go into engineering is because "they are good in math and science in High School"
Where is the mechanical aptitude?
Coding and software are better choices.
All you have to do is ask yourself ..How many young girls ask for toy electric trains for Christmas...
Our EE consulting firm in Pa. has the same name as a fitness supply company in the SE USA and we had no problems, although they do want our domain name. JIM
It is common knowledge and often noted that IEEE 1584 does not apply to LV single phase systems and the results are conservative for example 240 volts three phase systems sourced from "small transformers" as well.
Plant electrical personnel quickly loose confidence in arc flash studies (labels)...
It is also not uncommon practice in utilities, that if a CB is over-dutied and if the actual fault current is above the CB rating that the CB (as controlled by the CB relay) is blocked from tripping and the upstream CB operates.
Assuming the upstream CB is rated for fault current.
Jim
