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  1. DTR2011

    What is Metering in SEL 700G? How d

    SEL-700 is a generator protection relay with multiple CT inputs and VT inputs. It has a large variety of available metering quantities and logging available. SEL-735 is a revenue grade meter with a single set of CT&VT inputs. The 735 has several power quality metering and event reports that...
  2. DTR2011

    345kV Ring Bus Extension, GIS

    Can you build up or down? You should really consult with a GIS vendor to see what’s possible. Where do plan to split the ring to add?
  3. DTR2011

    SEL Relay CTR/CTRG/CTRN

    If you wire the CTs in a residual connection through the 4th CT input (Ig or In), you can see both. Our distribution company does this on a 351A application to have more ground elements available.
  4. DTR2011

    Opinions on remote breaker operation for 34.5kV Switchgear

    Make sure the floor is level. Make sure when the gear is installed that the gear is properly shimmed and level and the breaker cradle accepts the breaker properly. If you have remote racking and poorly leveled gear you will have a whole new set of challenges to deal with if something gets stuck...
  5. DTR2011

    Power Transformer

    Have you checked for DC ground faults? Many of them trace back to a transformer accessory.
  6. DTR2011

    Earth switch

    MV indoor switchgear in ANSI world there is a device called a ground and test breaker. It is designed to rack into the front switchgear, in place of a breaker. There are 6 stabs, which are isolated from line/load and phase to phase. It is set up so voltage can be checked live or dead. Also...
  7. DTR2011

    When do you require Current Transformer in/out switches?

    If you are subject to any kind of regulation for testing, the test switches will pay for themselves during commissioning. I recall 20 years ago testing relays for multiple generator locations that did not have test switches. At the time, I had an electrician by my side to remove and land wires...
  8. DTR2011

    Transformer purging after tripping off line

    How about purging the space with nitrogen.
  9. DTR2011

    Direct Lighting Strike on Power Line

    I don’t know much about the arcing horns, other than we remove them and the bus arrestors as part of a station rebuild. New Zno arrestors are installed on the lines. That smell of a new arrestor is almost sweet. We’re going through an asset renewal phase where OCB’s, disconnect switches and...
  10. DTR2011

    Kingsine or Ponovo experience

    Maybe enough Sverker 900 fans can get Megger to accelerate the start up time of the unit. That’s my only issue with Sverker.
  11. DTR2011

    Direct Lighting Strike on Power Line

    We’ve come a long way since these.
  12. DTR2011

    Kingsine or Ponovo experience

    I haven’t seen or heard of these units in use in the United States. As you mentioned Omicron and Doble are popular. What are your needs? Automated testing or simple testing and a 3 phase source? My company has 6 Dobles and an Omicron. We also have 2 Megger-Sverker 900’s. The Sverkers are...
  13. DTR2011

    Map-Operation of distance relays located near Voltage source convertors

    I know of an HVDC station that caused all kinds of problems with power line carrier systems, including the PLC based AMR system on the distribution lines.
  14. DTR2011

    Testing 12kv rated capacitors

    How about testing with Doble at 120V and both parties are happy?
  15. DTR2011

    Omicron overcurrent protection testing

    If you look in the help of the SW, it will step you through the process. There are pdf and videos on how to do this in multiple languages
  16. DTR2011

    Relay Settings for Ring Bus

    We use a scheme where the MODs open circuit is wired in series with the two breakers 52b contacts to prevent opening under load.
  17. DTR2011

    Digital Relay Loosing it’s Mind

    Well we think we found the culprit... The site uses SEL Team SW in the station computer. Team uses Modbus to retrieve the event reports for the UR relays. Apparently, GE changed the Modbus addressing at some point, so that what should be a data retrieval register is now a write register...
  18. DTR2011

    Digital Relay Loosing it’s Mind

    We are actively working with the manufacturer to resolve the issue. They have been able to replicate the issue with our settings at the factory. There was a fairly serious meeting with top management of the utility and OEM. So far none of the suggestions from the manufacturer have worked...
  19. DTR2011

    Digital Relay Loosing it’s Mind

    We are finding that out every step we take in trying to resolve this issue. It was pure coincidence that this was found in the first place. Imagine setting up a relay, testing it for 8-12 hours and maybe tomorrow SOME of the latches fail to operate but the corresponding LED says it is....
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