Meaning of ROV Trip for Relay ABB

[SA07]

Hi
a) Can you plz tell me what does ROV Trip on the relay mean?
b) Is it possible to set nominal voltage in a relay ABB REF615 a value less than 11 kV e.g 10.6 kV? Or there are standard values like 6.6, 11, 20 kV we must choose from?
Actually we have 10.6 -10.8 kV on our busbar. We have increased the transformer tap changer to the maximum. The idea is to avoid tripping by under voltage e.g if we set UV 0.85 2s

 

[davidbeach]

What does the instruction manual have to say about it?

I’ll see your silver lining and raise you two black clouds. - Protection Operations

 

[esperantes]

Residual Over Voltage.

Characteristic Value
Operation accuracy
Depending on the frequency of the measured current: fn ±2 Hz ±1.5% of the set value or ±0.002 x Un

 

[RRaghunath]

The relay REF 615 has setting range for Voltage input - 60 to 210V.
If you have set 110V corresponding to 11kV, it can be reduced as corresponds to 10.6kV I suppose. You can verify in the relay model that you have in the field.
These numerical relays are very flexible and you shouldn't have any problem choosing 10.6kV as your rated voltage in the relay.
Even the UV protection threshold setting is adjustable from 5% to 120%. So, if you wish you can have lower setting than the current one (85%).
ROV stands for Residual Over Voltage function which senses earth faults downstream by measuring the residual voltage (vectorial sum of three phase voltages). ANSI function number is 59G.

 

[SA07]

Thanks a lot for the info