Here's another file.
I don't know how those add links got into my previous post!
REAL MEN LOVE JESUS!http://files.engineering.com/getfile.aspx?folder=2c04bd94-3e47-4ea1-b115-e4e3145f1091&file=3phaseVolts1.ppt
bacon4life - sorry I overlooked your question - No, no trips on station feeder or on OCRs.
wareagle and davidbeach - blinking is probably not the best word to describe. Flicker is more accurate. Some early records show momentary dips down to 90 VAC at customers meter.
Dumbo2929 - sounds...
Sorry to take so long getting back. You know how it is, busy.
I don't have the software or IR cable to be able to read data.
Budget is tight, so, I was just hoping someone had also experienced this type of problem to help us decide whether to change the cap bank controls to a different...
On 13.8 kv circuit we've had customer complaints of blinking lights. After visually inspecting the circuit the only unusual condition was a 3 phase pole top capacitor bank (with Beckwith M-2501B Autodaptive control) installed one pole span downstream of 3 single phase line regulators.
I'm...
I've had "Introductory Circuit Analysis" and ABBs "Protective Relaying Theory and Applications" book (ISBN: 0-8247-9152-5) for a few years. I was recently given a "J & P Transformer Book” and just received my "Electrical Transmission and Distribution Reference...
A little follow up - I took the Arbiter power meter back to the A-C-B station. If you program it's polarity to (+) you read the same angles the Dranetz reads at the A-C-B station. If you program it's polarity to (-) you read the same angles the Dranetz reads at the A-B-C station.
After...
Thank you gentlemen for responding. I'm beginning to under stand. It's mainly a nomenclature and terminology issue.
jghrist, when you say Georgia and Duke Power use reversed phase rotation, do you mean they connect their transformers A-H1 C-H2 B-H3 (A-C-B) but their generators run A-B-C (A...
rbulsara - the grid I'm speaking of is the 115kv grid. The same grid that's interconnected throughout the USA (at higher kv). My understanding is that all generation in the USA (that's not islanded) is A-B-C CCW. It only changes sequence through transformers.
At the A-C-B station:
H1 & X1...
jbartos, all of our stations have one-line drawings showing the bus configuration, breakers, switches and transformers. The one-line indicates which phase hits each transformer HV bushing.
If both stations had the same sequence then wouldn't both A phases be the same?
Today I went to the...
busbar, no, not trying to parallel them. At the station with A-C-B sequence I needed to take phase angle readings before and after installing new metering PTs on the 13.8kv bus. They are now installed and the before and after readings were the same.
After analyzing the A-C-B readings I was...
I've been searching the forum and was almost convinced that my connections/phases and readings are correct and I just need to view the A-C-B phase rotation in the CW direction (while plotting the degrees in the CCW direction on both circles).
This is one of the threads (by redtrumpet). See his...
At two different stations, I took phase angles from A phase PT on 115kv bus to A B & C metering PTs on 13.8kv bus. I used a Dranetz Phasemeter - model 314. Both transformers are Dy1 and grid is A-B-C CCW.
The station with A-B-C sequence read:
HV A leads LV A by 32 deg
HV A leads LV B by 152...
I looked at two Dy1 Transformers today and neither had the Dy# designation on the nameplate.
It may be that manufactures don't list the Dy# on nameplates because customers can connect A-C-B sequence and cause a Dy1 to act as a Dy11. Just a thought.
mvcjr - without the Dy# on the nameplate you...
Thanks jbartos.
Dy1 is common to my area. I seldom get an opportunity to see nameplates on transformers other than type Dy1.
It's good to know that overlapping vectors does indicate leading or lagging phase shift since nameplates don't designate Dy1, Dy5, Dy11, Yd1, Yd5 or Yd11 (I haven't...
Am I correct that simply overlaying vectors on transformer nameplates will indicate the phase shift from primary to secondary? Is this true of all transformers nameplates - Dy5, Dy11, Yd1, Yd5, Yd11, etc...?
For example, a Dy1 vector diagram from one of our 115D/13.8Y transformers - if you...
What type relays do you have?
If you have micro-processor relays you can set your coordination pretty tight. You can set logic in the main relay to block tripping as long as the feeder is timing out. You would need a 2 conductor cable from the feeder to the main so the feeder can send the...
