Testing of Reverse Power Relay

It should trip during a mains outage...otherwise might try pressing the test button....

http://www.larsentoubro.com/electrical-automation/products-services/products/relays/generator-protection/mrp11-reverse-power-relay/

In this MRP11 relay can we connect the terminal 11 and 12 to the direct line voltage with out transformer, why we provide a transformer,please explain

The transformer is part of the system, it reduces voltage for proper calculation measurement...

such as:

https://wss.woodward.com/manuals/library/Protection_Relays/professional_line/xp2_r/DOK-TD-XP2-RE.pdf

Yes. The supplier of the equipment can describe the <...method to test it...>. Whether the <...we...> can <...check...> is not something the forum can really comment on. Telephone?

If this relay were "by name", nominal, 120 volts and 5 amperes: which are often used for 60Hz PT secondary volts & CT current ratings: then the nominal power would be 120 volts x 5 amps = 600 watts.

If you connected a 120 volt 0.5 amp load [say a 60 watt incandescent filament bulb or wirewound resistance] to a suitable supply that would be 60 watts. You might have to compensate for relay power [burden] if it is not negligible.

Feed the load current through the relay CT terminals & connect its PT terminals across the load and you have a 100 x (60W/600W) = 10% setting power at relay.

This may be enough to do a "it works at near the expected power so it is OK" test. [ you can alter the relay setting to be above & below the available watts].

Measuring amps & volts with 1% accuracy you have a reverse power of say 10% +/- 0.2%. For the usual reverse power protection, such an error is not significant.

Of course, reversing a CT or PT connection will prove the relay is directional.

If you want to do an exact watt setting or check you need a variac to adjust voltage and/or a variable resistor for load. A selection of resistors or incandescent lamps may be sufficient.

Proper relay schemes have test blocks built into the relay or the circuit, so that a relay secondary test set can be plugged-in with no disturbance to wiring.