Short of installing ballistic protection around substations, visual screening might do some good in mitigating firearms damage. If you can't see what you are shooting at, the probability of damage per round fired goes way down. And the probability of detection and apprehension goes up the more...
I'd suggest consulting with a crane company. Find out what sort of equipment they'll need to lift that sort of weight to a height sufficient to clear buswork and other stuff and then swing the load to a flatbed truck. And what the footprint of that will look like. You might find that the...
It does seem to be a bit confusing.
R1/R2 = l1/l2 = A1/A2
seems wrong (top of page 12-21). The resistance of two similar pieces of wire vary proportionally with their lengths (R1/R2 = l1/l2). But the resistance of two similar pieces of wire vary inversely with their areas (R1/R2 = A2/A1)...
"Would the estimation of available capacity change if there are 600V - 208V step-down transformers downstream of the electrical distribution system?"
No. Not at the 347/600V service point. Your above calculations are correct.
Downstream of each stepdown transformer, the portion of the 175kW...
You could measure from both ends of the broken cable to the fault (break). If you know the cable's overall length when installed, the reflection time from each end in can be added and used as the denominator in the ratio of each reflection time to the overall time. The propagation constant drops...
You could call an electrical contractor that does underground fault location and cable repair. Have them bring out a cable location set (the kind that injects a signal into a conductor) and then trace it to its end points.
"I don't think that's the purvey of only PFC drivers."
It's not a property of power factor correction. The PTC resistor is usually included to keep from blowing up cheap capacitors due to inrush.
"I think the only industry that this is a big issue is Pharmaceutical jobs."
Aerospace (FAA certification), refineries (EPA), nuclear power plants (NRC) and pretty much any industry that has to demonstrate code and safety compliance.
"hundreds of distributed components that "register" themselves with the main processor on boot"
But that only works out to the boundary of these smart components and the real world. Somewhere, there is a drawing that defines the connection of various sensors on process piping and contacts...
"the firmware needs to be able to read the hardware version"
This will cover the PLC hardware version. But it doesn't address the hardware configuration of the overall system. Particularly, wiring and component revisions outside of the controller itself. PLC firmware can be controlled...
"Then there is combined inrush on LEDs I'd have to worry about.."
That's the inrush of the LED power supply (charging a cap). Well-designed supplies incorporate some sort of PTC resistor to limit this inrush. The result being a slightly unnerving start up time when you flip the light switch.
"Two single breakers and a shared neutral are not recommended."
Not code either, IIRC.
"I had to do vector analysis to convince myself no current would flow in the neutral if both loads are equal."
For LEDs, there are going to be power supplies with their associated non-linear characteristics...
Are all those pump loads 3 phase? If so, I'd chase down the source of that imbalance. Current readings on each phase of each motor branch circuit should be taken.
It's possible that one of the motors has a phase winding that is going bad. High resistance results in an imbalance. But due to an...
What are the consequences of a fault on that overhead section? What will differential protection do to mitigate outage duration and/or repair costs? Is the 12MVA transformer already well protected for a through fault? What sort of faults do you expect on the several hundred yards of overhead?
Possibly for harmonic mitigation?
A diagram of what the utility is requesting relative to their service and system would be helpful. Simply adding a zig-zag grounding autotransformer can indeed cause problems. For one thing, you can create a path into your system for harmonics generated by...
Wierd. It would be interesting to see the VT open delta connections. With all the H and X terminals labeled. I can see how the VT setup will produce a delta shifted w.r.t. the station's primary. But I can also see that, for a loss of one phase on the station primary, there are going to be some...
