Easergy P5 Protection Relay Single-Phase 3-wire

[Hyeontae-Song]

Hello Team.

Can the Easergy P5 protection relay be used in single-phase 3-wire?

I attach a photo below.

In addition, please check whether it is possible in PM5560.

 

[Rudolf_Simon · Accepted solution]

Hello Hyeontae-Song,

from the photo it looks like a 3-phase application, may be with just 2 phase CTs ("2-CT").
Such application is feasible/possible with P5F30.

PM5560 I can't comment on.

Regards
Rudolf

[Hyeontae-Song]

Thank you for your reply.

However, single-phase three-wire wiring has different voltage levels.

Look at the picture below.

 

I know that the protection relay is measured on a 3-phase basis.

[Rudolf_Simon]

I would call this a 2-phase 3-wire application, where the red wire is ground/earth, and blue/black are phase wires with voltages 180° phase shifted.
Is it railway/ metro application?
If yes, then I would check for any railway specific requirements (in terms of functionality and hardware requirements; and also frequency - is 50 or 60 Hz?).
If no, and as no directional protection function is required per SLD (it shows just 50/51 phase OC and 51G neutral OC based on measured IN), then use of P5 would be feasible.
What is the purpose of "Ao" input?
Device power supply will be from 110 V AC? Which is ok from PSU input range, but bears the risk that the relay will power down during a short-circuit on the primary system, then cannot provide reliable protection. A so-called self-powered relay then would be more suitable (like MiCOM P115 or P116).

regards

Rudolf