Interlockings via FO connection

[lz5pl]

Currently we work on design of small substation 110/20 kV. Primary diagram is block Cable 110kV/Transformer 110/20 kV without circuit breaker on 110 kV side. Circuit breakers are installed on 110 kV bay on remote end (supplying feeder) and in 20 kV switchgear cubicle on our side.
Problem is that we have an earthing switch on 20 kV side of the transformer. This switch should be interlocked with remote end to avoid earthing of live transformer or the opposite - energizing from remote end with earthed 20 kV here. Such interlocking is not mandatory, as we have two separate substations, but it will be good to install it having in mind that our substation will be managed by industrial customer.

For the line differential protection we have FO-cable connecting two sets of relays on both line ends. I would like to use separate from relay protection I/O-modules interconnected via spare fibers. I know one such set from Siemens (7XV5653 Two-Channel Binary Transducer), but it is quite expensive and I am looking for alternatives.
One possible set is SEL-2505 Remote I/O Module. From it's Manual it is not clear whether contacts on remote end follow BI's or they make a trip pulse only. Do somebody have experience with these modules ?

Any ideas about similar devices from other supplier will be also welcomed.

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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

 

[slavag]

Hi.
If this not must and only your right additional, you can use
some remote I/O from PLC word.
I recommend check with local team, what company is have good tech support in this area and used it. It's so much companies with ranges of prices.
Best Regards.
Slava

 

[lz5pl]

Thank you slavaq, problem is that "PLC world" normally doesn't know operating voltages higher that 24 V DC
In my case they are 110 V in substation and 220 V on remote end.
I tried with Phoenix Contact, but without success.

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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

 

[slavag]

Xmm, sorry, forgot.
OK, possible add some PS to 24V and aux. relays.
Not so good solution, but is very cheaper.
Some kind of RTU, but you need RTU with CPU.
Regards.
Slava

 

[davidbeach]

A pair of SEL-2505s will work. The outputs at each end follow the inputs at the other end, changing state only when the input at the other end changes state.

 

[lz5pl]

Thank you davidbeach, exactly the information what I needed!

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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