ISA T1000 PLUS - Primary End to End Test

DOC. MIE91093 Rev. 1.34 Page 125 of 145
generation on the auxiliary output: the currents add, and
produce a second harmonic distorted current. This current is
applied to one of the relay inputs.
Test procedure:
 Connect the two currents to the relay input;
 Increase I1 only until the relay trips;
 Then increase Aux to increase the current from D1000
or TD1000, until the relay trip drops out.
Take note of the two currents and calculate the 2
nd
Harm %
 H
%
: the harmonic percentage is, with D1000:
100*
_
_
22
%
IExtIac
IExt
H


Or, with TD1000:
100*
21
2
22
%
II
I
H


1.16 PRIMARY END TO END TEST
The purpose of the test is the check the complete protective
scheme of a line differential relay, including the CTs. This kind
of test is particularly complex and requires a big effort in the
coordination of two teams of technicians at both ends of a line.
A a
B b
C c
N n
I
1
I
2
I1 + I2
100 Hz
50 Hz