"Made in England" but written in Russian indicates to me they would be immediately post-war (or built during the war) for export to Russia.  Reasonable given the time frame of the installation as well: they easily could have been dumped in a storeroom for a few years until Bulgaria was able to start rebuilding from the damage.

More important than the manufacturer himself is the "function"  the purpose of the relays.

Where do the input cables come from?  Is that equipment still use, or was it removed and replaced many years ago?

Where do the output cables go?  Same question: Where do they connect and is THAT equipment still use?  

Once you know what they connect, then find out if the relays actually still work.  They may be "frozen" and cannot move - even if you want them to protect some real piece of equipment, they aren't doing the job.  So then you need to know what "setting"  or trip point they are supposed serve.  

If they are needed, what is their purpose, and what can you buy today to do the same thing?   

Pipes and steel  and concrete can serve many dozen years.  Pipes can be replaced, steel painted and preserved.  But electronics?  And electro-mechanical parts?   They can break electrically (bad wires and burned out insulation and bad tubes) AND mechanically (stuck contacts and rust and failed springs and springs and latches that are painted solid.

You have an interesting research project.

In the lower left corner of each instrument is a "VM" (or "MV" logo: maybe the original builder was Vickers Manufacturing?

"Vickers Machinery" ?

Hi Slava,

They are by Metropolitan-Vickers, or Metro-Vick, were an old British company based in Manchester. Metropolitan-Vickers were the arch-enemy of British Thompson Houston (BTH) based at Rugby. The two companies merged way back in 1928 to form Associate Electrical Industries (AEI), which itself merged with English Electric in 1968 to form General Electric Company (GEC). GEC later passed through various guises as GEC-Alsthom, GEC-Alstom, and latterly Areva. In spite of the merger in 1928, BTH and Metro-Vick kept separate corporate identities until the 1960's, so those relays are likely to be a lot younger than 1920's vintage .

I can't help with the relay types themselves at the moment because my old reference books are all in by office at work, but there are a few English characters on the relays in " ". I have a feeling that the HHTA is a differential relay, possibly a biased diff for transformer protection. I'm much less certain about the others but the NSS is possibly a speed sensing relay.

Contacting Areva at the St. Leonards Works would be a very good idea. They could almost certainly identify these relays from a photo. They have pretty much all the design information going back to the days of AEI and have a fair bit from the days of BTH and Metro-Vick.
  

----------------------------------
  
If we learn from our mistakes I'm getting a great education!
 

Thank you [b]Scotty. Your posting is helpful as usually. Looking on the logo relays must be manufactured by Metropolitan-Vickers. The full story about these comapnies is very interesting to me. My experience started with GEC-Alsthom and further via all their transformations. Next year they will be something like Schneider-Alstom. I have been several times in Stafford and have very good impressions from people who worked there. But after they became more and more French-dominated our region was transferred to French- and further to German offices, so my last visit in Stafford was in 1997 or -98. By the way, I was pleasantly surprised to find amateur radio club in the factory and even made a couple of radio contacts from their transceiver!
A bit more about relays:
Relay with "NSS" is earth fault relay.
Relay marked "HHTA" is differential relay.
Relay "FXW" is trip relay.
I didn't ask whether these relays are still in use, but I seriously doubght it. After all these years springs have to be loosen, bearings not in good condition. But panels still stay and why to replace them if new relays need much less space?
I worked on 220kV and 110 kV part and also on one of new generators (new - end of 1970's). Even there some of relays are replaced with numerical ones and other are waiting for financing.

The idea to write here is first my curiosity in old types of equipment and second - the story which colleague from the power plant said to me. There are rumours that first unit have been delivered to Russia during the WW1, but after 1917-revolution there is nobody to install it and everything stayed as packed for many years. After WW2 when Bulgaria enter Soviet zone of influence Russians delivered it here. At that thime probably they already have specialists qualified enough to install the equipment and put in operation. Whether it is true or not nobody knows now, but if VM have merged during the 1930's this story may be true.

Plamen Natchev
www.triel.bg

------------------------
It may be like this in theory and practice, but in real life it is completely different.
The favourite sentence of my army sergeant
 

When I was at Gec Measurements I had a list of all GEC (General Electic Company - Not General Electric, did you guys know that GEC (UK) traded as English Electric in the USA?)/ English Electric (EE) / Associated Electrical Industries (AEI)/ Metroplitan Vickers (MV(), British Thompson Huston (BTH) etc relays.

Deeply regret that I passed the list on to my successor!

GEC St Leonards were well organised, and could trace all relays by the model number (not the serial number).

Earlier companies were less organised, and we could not trace the model numbers - which defined the build of the relay.

So anything before 1969 (when GEC / EE / AEI merged)and not a GEC / EE relay is open to doubt.

I was once called to a car factory on the north bank of the thames, east of london. They took me into the main HV switchroom.  Old electrical engineer had retired.  "What do you think of this, I was asked".  "Don't anybody sneeze", I said.

"Why?"

"This is AEI kit, they stopped making it 20 years ago.  If it fails, six months plus to replace it"

"Can you give us an exact replacement"

"No, the records were binned 10 years ago".

You can ask Areva, but good luck, not their fault.

Thank you Hoxton.
I don't going to ask AREVA, I would rather call directly guys from Stafford. I still has some contacts with older members of St. Leonards Amateur Radio Society, who worked all their life in the factory.
Actually I didn't expect much with raising this tread, as the relays are definitely very old. For me it was helpful even to find the name of the manufacturer - it have to be Metropolitan Vickers, which was unknown for me (what is normal having in mind that when speaking about electrical equipment Bulgaria always have been in "German zone of influence".
And if MV became AEI in 1928, that version that panels have been delivered first to Russia during WWI seems quite realistic !

------------------------
It may be like this in theory and practice, but in real life it is completely different.
The favourite sentence of my army sergeant
 

lz5pl,

Metro-Vick continued to operate almost as a separate company from BTH right up until the 1960's even though they were both part of AEI. My guess is those relays are likely 50 - 60 years old.

We actually have a handful of HHTA relays at our site which are still in service, although I think they have GEC's name on them. They will be getting scrapped when we replace the switchgear in the next few years - I will try to save one for you.
  

----------------------------------
  
If we learn from our mistakes I'm getting a great education!
 

Metro-Vick continued to operate almost as a separate company from BTH right up until the 1960's even though they were both part of AEI.
================
It is interesting! I am curious if AREVA would continue produce relays with their logo after joining this year Schneider Electric       

------------------------
It may be like this in theory and practice, but in real life it is completely different.
The favourite sentence of my army sergeant