Relay brands


The question "Which relay brand is good?" was asked on LinkedIn. A few specific answers were put forth. This is my response, which has been quite well received:

Isn't the best relay the relay that meets your specific needs in the most cost effective and reliable manner? I know this is a non-answer, but every case is going to be different. I've used many of the different brands, and some 'felt' better to me, but other engineers and technicians prefer others.

I reckon the reliability and protection functions are going to be much of a muchness — they'll work, and they'll keep working. What distinguishes the different brands are:

  1. Local support. If you have a problem can you get help in your country in a timely fashion? No point having the best relay if you need to schedule a visit from a support engineer from three countries away.
  2. Free access to programming tools. Some vendors still insist of charging for their programming tools. WHY? Surely the relay is the 'dongle'! My preference is to use the tools that are free to download, and that are easy to use for programming and diagnostics (e.g. event & waveform downloads). Do these tools support data warehouses and revision control systems?
  3. Panel space & wiring. Some relays are HUGE — is this really needed. Can you easily remove a terminal block or slide out the relay if a replacement is needed? Integration flexibility. There is huge variation in how IEC 61850 is implemented by vendors. Do the relays work with logical nodes 'natively' or is IEC 61850 seen as another bolt on protocol like DNP3? Do they support enough report control blocks? Can a dataset be used by more than one RCB or Goose control block?
  4. Documentation — this is linked to (4). Can you get the documents you need to design a system from the vendor and without the need to install all the programming tools? Getting hold of application manuals, MICS, PICS, PIXIT etc all make life easier at the design stage.
  5. Cost. Utilities have budgets to meet, and there is significant variation in pricing (lets not talk details in this forum though). Remember to include support agreements, programming tools, training etc in the costs.

Just my thoughts, and I'd be interested if others expanded on what they used when deciding who to go with for projects or 'panel of supplier' contracts.

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