Sepam - HV/MV Protection and control units (ENG) - Trinet

InstallationUse and connection of ACE 990 interfaceThe ACE 990 is used to match the measurement of aMV core balance CT with ratio 1/n (50 ≤ n ≤ 1500),with that of the residual current input of Sepam 2000.So as not to downgrade measurement accuracy, theMV core balance CT must be able to supply sufficientpower. The value is given in the chart opposite.ConnectionTo wire the ACE 990 interface correctly, the followingmust be known:c ratio of the core balance CT (1/n)c core balance CT power,c close approximation of Ino (1) rating, essential forSepam 2000 protection setting.The chart opposite may be used to determine thepossible choices for the connection of the ACE 990interface primary circuit to the Sepam 2000 earthcurrent input, as well as the Ino (1) setting.E5E4E3E2 S2E1 S1ACE 990Example of wiring.ECA/ECMA6A5A4REFA3A2A1The exact value of the rated Ino (1) to be set is givenby the following formula:Ino = k x number of core balance turnswhere k is the factor defined in the chart opposite.Example:The core balance CT used has a ratio of 1/400 andpower rating of 2 VA.If the earth fault protection settings are between 0.5 Aand 85 A, the rated Ino (1) used may be 10 A.This value makes it possible to accurately measurefrom 0.5 A to 100 A.c Calculate the following ratio:close approximation of Inonumber of turnsi.e. 10/400 = 0.025c In the chart opposite, find the closest value of k.A close value is k=0.02632.It corresponds to core balance CTs that are supposedto deliver at least 0.1 VA of power.c In the chart opposite, find the wiring thatcorresponds to the value of k.The secondary circuit of the MV core balance CTis wired to terminals E2 and E3 of the ACE 990.The terminals S1 an S2 of the ACE990 should bewired to terminals A2 and A4 of Sepam 2000respectively.c Calculate the value of Ino to be set:Ino = 0.02632 x 400 = 10.5 AThis value of Ino may be used to monitor a currentbetween 0.5 A and 105 A.value of k ACE 990 Sepam 2000 Min. power deliveredinput input by MV core balance CT0.00578 E1 – E5 A2 - A4 0.1 VA0.00676 E2 – E5 A2 - A4 0.1 VA0.00885 E1 – E4 A2 - A4 0.1 VA0.00909 E3 – E5 A2 - A4 0.1 VA0.01136 E2 – E4 A2 - A4 0.1 VA0.01445 E1 – E5 A1 - A4 0.4 VA0.01587 E1 – E3 A2 - A4 0.1 VA0.01667 E4 – E5 A2 - A4 0.1 VA0.01689 E2 – E5 A1 - A4 0.4 VA0.02000 E3 – E4 A2 - A4 0.1 VA0.02212 E1 – E4 A1 - A4 0.4 VA0.02273 E3 – E5 A1 - A4 0.4 VA0.02632 E2 – E3 A2 - A4 0.1 VA0.02841 E2 – E4 A1 - A4 0.4 VA0.03968 E1 – E3 A1 - A4 0.4 VA0.04000 E1 – E2 A2 - A4 0.1 VA0.04167 E4 – E5 A1 - A4 0.4 VA0.05000 E3 – E4 A1 - A4 0.4 VA0.06579 E2 – E3 A1 - A4 0.4 VA0.08671 E1 – E5 A3 - A4 2 VA0.10000 E1 – E2 A1 - A4 0.4 VA0.10135 E2 – E5 A3 - A4 2 VA0.13274 E1 – E4 A3 - A4 2 VA0.13636 E3 – E5 A3 - A4 2 VA0.17045 E2 – E4 A3 - A4 3 VA0.23810 E1 – E3 A3 - A4 4 VA0.25000 E4 – E5 A3 - A4 4 VA0.30000 E3 – E4 A3 - A4 4 VA0.39474 E2 – E3 A3 - A4 6 VA0.60000 E1 – E2 A3 - A4 10 VA(1): this is the current value for which the earth faultprotection setting rage extends to between 5% and 1000%of this value, at the most.1/20 Installation - Use - General characteristics - Testing