Hi Folks,
I am at an electric utility and an item that has continued to come up at our Union Labor Management meetings is if we are doing adequate initial grounding testing and adequate annual inspections of Load Break Switches. I would be very interested to hear what people do for initial...
We recently had a very large fault on one of our 34.5kV Subtransmission lines. It was a phase to phase fault (no ground involved), and the fault itself was about 11,000 Amps. As you can imagine there was contribution from a large number of sources, as it is a looped system. At one of the...
Howdy,
I am looking for sagging information with regards to spacer cable, in this case Hendrix. I normally use Sag 10 and PLS Cadd for transmission line design but have not had to design underbuild with Hendrix Spacer. I assume I am mostly interested in the sag of the steel messenger, along...
Folks,
I had posted a few weeks ago about a strange phase to phase voltage imbalance measured on the secondary of a three phase 12.47 x 277/480V transformer bank. We recently checked another bank further down the road and have the same issue, 208, 208 and 217. The 480 bank measured 480, 480...
One more question on a totally seperate issue. At one of our substations, we have 15KV cables coming off the low side of a 34.5 / 12.47 KV transformer. This feeds our low side bus which feeds the four feeders. The cables are Jacketed Concentric Neutral cables and there are 3 - 500MCM copper...
Folks,
We are having an interesting voltage problem at a water pumping facility and I was hoping someone might be able to shed some light. The setup is a a three phase overhead power bank, made up of three 167KVA, 12.47kv / 277/480Y service. The service enters the building into the main...
Howdy,
I am curious if anyone has had experience with microturbine installation. In my case, the customer wants to install a 20kw turbine in the city water supply at a pressure reducing location.
My question is, if anyone has had experience, what type of protection have you used, and how...
Howdy,
I have recently been working on a voltage complaint for one of our customers. It is an elementary school at the end of one of our 12KV feeders. The three phase ends about 5 miles before the school and two primary phases continue on through the town and end up at the school. The...
I am looking for sort of the same thing that mpparent was looking for. In my situation, I have introduced a couple new 115/34.5kv sources to our subtransmission. Off of our subtransmission we actually have a few feeders that are directly tapped to the 34.5 kv through a recloser and regulators...
Hello All,
I am currently setting up a three phase distribution step-down bank as part of a voltage conversion. This will be three 250KVA Single phase transformers connected ungrounded Y - Delta. My question is, if the impedances of the transformers do not match, I have been told you will...
I have begun my career as an Electrical Engineer in the utility feed and have been thrown right into it. There has been a large push to correct power factor at our tie points to near unity. My question is, is there info or literature that puts ferroresonance in understandable terms? I have read...
