lz5pl
Electrical
- Feb 6, 2007
- 313
This year we won an order for maintenance testing of relay protections in old thermal power plant. Until test set works instead of me
making automatic test of distance relay I made walk in control room and found several relay panels with very old relay protections. I know almost any type used in our grid (Bulgaria) but these relays are very specific. On their front plates is written Made in England, but in Russian language! This power plant is built in the end of 1940's, actually first unit is put in operation in 1949, exactly 60 years ago. First two units have been in operation until 1970's, but 6 kV switchgear which belongs to them is still under voltage, suppling station auxiliary services. Circuit breakers are oil type (don't mix with minimum oil!), maintenance people says that these breakers are very robust and reliable.
Relay protections on the photos are overcurrent relay, differential relays (it is written in Russian "Translay" on their name plate) and lock-out relay. There is no name of the manufacturer. They are not in operation now (or at least some of them?!), but panels stay intact.
This power plant is built by Russians, but why first unit together with all switchgears and control and protection panels are equipped by English relays is some mistery for me.
Can somebody recognize these relay protections and give me idea which company have manufactured them? There is nothing on the Internet when I try to search just by types.
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It may be like this in theory and practice, but in real life it is completely different.
The favourite sentence of my army sergeant
Relay protections on the photos are overcurrent relay, differential relays (it is written in Russian "Translay" on their name plate) and lock-out relay. There is no name of the manufacturer. They are not in operation now (or at least some of them?!), but panels stay intact.
This power plant is built by Russians, but why first unit together with all switchgears and control and protection panels are equipped by English relays is some mistery for me.
Can somebody recognize these relay protections and give me idea which company have manufactured them? There is nothing on the Internet when I try to search just by types.
------------------------
It may be like this in theory and practice, but in real life it is completely different.
The favourite sentence of my army sergeant