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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...

Hi Thanks for the paper interesting reading, however still I am still a little confused. I am essentially trying to prove that mutual induction is in fact taking place between these two parallel lines what would be the best method to follow to to prove this ?

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 regarding the following two pints 1. "the quality factor of the steam" and secondly 2. " the vapor fraction of the steam " They are two entirely different physical characteristics. Could someone perhaps explain the difference ?

I checked the steam quality cals for increasing it is 93% and decresing is 97%, I am try to verify if this is acttually valid. I am not sure if I am calculation the enthalapies correctly, for example if the pressure inside (p1) the vessel is 8 bar, I use the hl (enthalapy of saturated liquid...

I used the armfield TH3 apparatus to conduct the experiment, you measure pressure and tempreture inside the vessel, and then throttle and measure outlet tempreture I would assume at atmospheric pressure. I attached a picture of the setup...

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...

Yes I have, we used an Omicron aswell, However it can be quite a challenge depending on the relay Burden and test set VA rating

Hi, For interest sake what test set are you using to secondary injection test the LZ32 with ?

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 Have you tried to contact doble ? I would assume they should provide you support for this type of problem if you have purchased their test equipment. Ideally like you said you need to understand how they derive their bias characteristic in both the relay and test set software. Personally I...

Some other things to perhaps consider I would also check on the filtering capabilities of the protection relays. This should not be really be a concern with modern numerical relays but can pose a problem with older static type relays that may be using basic filtering techniques. Secondly I not...

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...

I am already performing the connection to the device via a serial server using tcp and psuedo serial comms ports. At this stage I am just investigating the possibility of another option using the method described . I will do some more exploring.

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...