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The currents flow as they would in any Delta connected circuit. The return path for line current Ia would be through line Ib and Ic. If you ask questions, others may think of you as foolish or ignorant. If you never ask questions, you will remain foolish and ignorant.

David Is there sufficient compensation to cause the faulted line angle to be less than 30 deg?

oldfieldguy is on the right track. I have dealt with this problem many times. While it is true that many e/m relays have two taps on the target/S.I. unit,(.2 & 2A ?) lockout relays by design are very fast and they require little current to operate. Hence, the current that operates the target...

I'm not trying to over-simplify, but your numbers look to me like you've a cap (or two) stuck on C phase. Remember that even if the phase currents are equal, but the angles differ significantly from the normal 120 deg, you will have neutral current. Overall, your pf may be near 1, but with the...

Different gases occur for different reasons. The rapidly elevated Ethane, Methane, and Ethylene numbers signal something very hot in the compartment. Normally operating circuit breakers (and tap changers) generate very little if any Ethane, Methane, or Ethylene.

Most troubling are the Ethane, Methane, and Ethylene numbers. These are "heating gases", or more accurately stated, over heating gases. Something in the TC is getting very hot. Also of concern is the Hydrogen. This occurs with partial discharge or low level "corona". Was the "changed" oil new...

Along with the water, you can expect animal inhabitants as well. Animals bring debris of all sorts. As soon as possible, I would inspect the bus for a buildup of debris which can hold not only moisture, but corrosive contaminants. Another point to consider is mechanical stresses caused by...

We have had very good service from the Areva/Bitronics M571/M871 series units. They are very versatile. Each unit has trending, DFR(2), and disturbance recorders(2) and lots of memory.(up to 128 MB). Ethernet,RS485, RS232 (com ports are configurable and totally independent) Modbus on one, DNP...

A simple sign in procedure at the SEL website will provide you with access to not only a user manual for the 121, but a wealth of related info as well.. www.selinc.com

Probably not an FPL guy for much longer...

Defeating protection on a hot, humid day with higher than normal load? Somebody better have their story figured out really, really well.....

My employer has rules about phone, email, and internet use while I'm on the clock being paid. Personal business of any kind is not allowed at any time, for any reason. I follow the rules. Always (only exception is sick, injured, or dead relative) I have personal rules about phone, email...

1. No, I wouldn't. We use Beckwith controllers and have several circulating current/paralleling schemes in use. Our practice is to supply 1 grounded conductor from one transformer control cabinet, and carry that conductor to all other points (such as the a and b contacts from the main and bus...

The vibration/resonance idea is interesting. I believe it is important to remember that buildings and structures of most any shape/size can have many resonant frequencies. I once found that a rather large gymnasium had three acoustically resonant frequencies using a signal gererator, a rather...

Agree with oldfieldguy. Additionally, O2 occurs as a result of the aging and degradation of paper insulation. If the transformer is of relatively recent manufacture (6-10 yrs.) your oil may contain an O2 inhibitor which in effect "absorbs" oxygen and keeps the numbers relatively low. As the...

Oh, by the way, you don't have to be crazy to do this kind of work, but it sure helps.

What can be accomplished? Well, let's see. 1. installation of spacers on bundle conductor lines to maintain proper spacing of the conductors. 2. Installation of vibration dampeners to stop "galloping" of the conductors under certain wind conditions. 3. Repair of damaged conductors (Yep, there...

Scary is: Finding the 300 mcm copper earthing conductor missing on 2 grounding transformers (zig zag)leaving more than a dozen transmission lines without ground fault protection. Should we cry over the bodies of dead copper thieves? Not me.

Duh! My bad. Forget my reply ovlac. Re-read your post. Agree with waross.

This sounds somewhat like an attempt at creating a "broken delta" connection which is typically used to provide a polarizing quantity for directional ground fault relays. I attempted to diagram the connections that you described, and if the the connections to the Y winding of the "B" phase pt...