ref high impedance testing

[golubgolub]

Hi All,
I would like to know what is test procedure for testing High impedance REF Protection. How to perform ''secondary'' testing? Should I inject voltage on stabilizing resitor and increised it until relay operate? Or I should inject current in secondary side and increised it until relay operate, and measure voltage on resistor to see the operating value? What is ''normal'' or ''standard'' commissioning procedure....
THX

 

[krisys]

If you want to perform the secondary test, just apply the set voltage and check whether it operates. You can apply voltage through the series resistor also, no risk of damage, as the current is very small.

 

[dfdt]

Isn't the two one and the same thing? i.e. inject current with stablising resistor in series with the relay or inject voltage across resistor and the relay. The important thing is to include stabilising resiston while doing secondary injection

 

[krisys]

bholas,

You are right. To make it simple, apply voltage directly across the relay terminals and check whether it operates at the set voltage or not.

 

[golubgolub]

thx....
ok,but it is connected to current input of the Protection relay.... So that means that I cannot just inject voltage on current inputs. This is for HZPDIF function in ABB relay. So I need to have current which will flow in to the relay