Recent content by NAZ55

Thank you for all the responses so far. Very helpful. Do you all know which standards apply here? IEEE, ICES, CSA, ANSI, IEC. Sincerely, Zeeshan

Looking for some suggestions on possible causes of radio interference on a 230kV line, which would be in the frequency range of 70 to 250 MHz.

Bill, We don't have spare CT available, nor do we plan on changing any phase to ground connections to phase to phase. Do you know why I am getting A and B phases to be 180 out?

Bill, Here's the connection I was thinking of, but unfortunately during the actual test it appears that A and B phase are 180 out. Can anyone explain with the math why? http://files.engineering.com/getfile.aspx?folder=1a922980-c852-457f-927e-a7af827eebc5&file=CT_connection.jpg

This is a metering Unit. No relay protection is intended. Any modifications would be a temporary fix until the unit is repaired.

Also, just to clarify by combined unit, I mean it's the instrument transformer where both the CT and PT are combined in one housing.

Hello All, One of our high voltage combined instrument transformers has failed and has to be replaced. I am trying to figure out a way where the secondaries of the remaining two CIT's could be used to create voltage and current for the missing unit for a balanced 3 phase power system. Will...

All, I have been asked to look into the probability of Main Power Transformer (230/35kV) failure should one be implemented without high side arresters. The thought process behind this is to figure out the affect of energizing a transformer without an arrester due to lead times of the...

What type of cables does this section applies to? Does it apply to instrumentation cables, which are covered under 727? What's the purpose of this limitation? Any suggestions will be greatly appreciated.

jraef, thanks for your response. My question is in regards to a high voltage air-disconnect, where the quenching medium is air. My concern is that the arc from the blade on the switch jumps over to the conductor (connected to the jaw side of the switch) during closing and stays on until the...

Does anyone know of any chart, code or standard that describes minimum metal to metal spearation for different high voltages during switching to avoid and arc? I have read some references where it talks about accounting for 1 ft per 110kV, but am not sure where that number came from.

This is an interface with a Utility, which only provides KYZ output from their meters. I just need to get a pulse counter that can support serial modbus or DNP to SEL 3530.

I am trying to figure out a way to get KYZ pulses from a revenue meter into a SEL3530. I am therefore looking for a middleman relay that would take KYZ output from the revenue meter and then convert that info. to a serial modbus or DNP communication to take over to a SEL3530. Any suggestions...

ek, please review NEC 310.

Cranky, I understand that a drain coil in series with capacitors functions as a high pass filter for carrier frequencies, but I also understand that it's an optional accessory, which comes only if a CVT is ordered with carrier accessories, thus making it suitable for PLC communications. It's not...