Hi
I am looking for some information and perhaps reasons why one would use the following criterion to limit restive reaches to mitigate overreaching in an Impedance relay's
For earth faults the resistive Zone 1 reach is limited by 4.5 <= X1
For phase-to-phase resistive reach of Zine 1 is...
Hi All
Upon reading the IEEE Std 62-1995 which indicates that a three-phase transformer may be tested for impedance using a single-phase power source . The test is done by short-circuiting the three line-leads of the low-voltage windings and applying a single-phase voltage at rated frequency to...
I see a closed thread from an earlier date, which reads as follows:
" CDG16 (Electrical)(OP)20 Jan 05 23:31
We have two 132kV lines on the same towers for about 100km. In the past we have used a portable transformer and generator to test ZSMC on parallel lines by injecting around 140A on the...
Hi All
After conducted a throttling experiment with water and noting the results. I would like to verify if it they make sense. What I noticed as that when the pressure inside the sealed vessel increased from say 1 to 7 bar in 1 bar increments the quality factor of the steam remained fairly...
I have some theoretical questions about clutches that I would like some clarity on, I have answered them and would just like to check my understanding.
1. what is the relationship between frictional torque and axial load.
it is proportional ie linear as axial load increases so does frictional...
Good Day
Is anyone familiar or has experience with test requirements for the telecommunication circuitry that would link to sites. The protection relays at the two sites are linked via a Newbridge BME Multiplexer device using radio as a communications medium. I wish to know from a...
Hi
I am having problems while attempting to upgrade the firmware on this device. The upgrade appears to work as the version on the relay changes to the latest version but PCM600 indicates that the upgrade has failed.
Any ideas ?
Hi all
Just a speculative question, why can we not get a YNd6 vector group transformer. Is it because of the limb design and winding process used in YNd type transformers.
Hi
I would like to know if anyone knows what the default password is for this device, and secondly if it needs to be set to use the webpage interface from the front port. I turned on the setting under the HMI menu however it still does not display the WHMI. Any experiences ?
Gooday All
I have this spesific relay "GEC OPTIMHO LFZP 112" on my network which uses an old piece of setting software called opticom, I would like to know if anyone is aware of newer software that will work with this relay and if it is windows based and what communication cable is required. I...
Hi
I am trying to understand the concept of serial to ethernet encapsulation. I can appreciate that the serial comms suite can be packaged within a TCP packet and sent across a network and will be unpacked at the remote TCP ip device back to serial. But I suppose my real question regards...
Hi
Has anyone experienced incorrect flagging on the front of these relays for single phase earth faults, it shows/flags more than one phase for a pure earth fault trip/operation
thanks
Hi
I am looking for experiences people have had using this legacy software, the problem I currently have is once I have installed all the software packages in the suite (which is quite a few) I can successfully connect to the relay. I can read and write PST settings but the moment I start up...
Hi
When calculating the shear stress between two parallel plates which are moving in the same direction at different velocities with a fluid sandwiched in between is it advisable to subtract the two velocities namely ( V1 -V2 ), and assume the one bottom plate as now stationary with the...
Hi
I have a ASEA 2BZ1 bus zone scheme protecting two busbars being zone 1 and zone 2, there is currently an isolator parity alarm being generated but the manual is not very clear what might be generating this alarm. I am thinking it's just the auxiliary contacts from one of the isolators but...
Hi
After reading the IEEE STD 1036-2010 refaurding the use of shunt capacitor banks on power systems there still remains an issue I am unsure of. The standard provides a formula to calculate the peak inrush current in a double bank energizing scenario, I have the following question's wich need...
Gooday
I have a 400kV L-L 100MVAR 50Hz SCB connected through a 1.2 mH Inductor and 3204 uF Earthing Capacitors to ground, there is a surge arrestor located in parrallel to the inductor and earthing capacitors on the low volts side of the bank. I would like to know what the primary functions of...
