ISA T1000 PLUS User Manual page 120

DOC. MIE91093
of the curve will not be tested. With TD1000, the maximum
value for I2 is 20 A; if the current I2 is greater than this,
connect the AUX output as with D1000.
As the curve is of the type parameter versus parameter, all its
points are the result of a threshold test. The area below the
characteristic is the no trip zone; the area above is the trip
zone.
st
1 test
The trip time is independent upon test parameters; so, it will
be measured in a first test, as follows.
 With I1 = 0, press ON and increase the auxiliary voltage
acting on the knob (20) until the relay trips: the fist point
is found, as it is the differential current when the restraint
current is minimum; test values are:
Restraint Current:

Differential Current:

just generate IA and IB (test with TD1000).
NOTE: it is impossible to test the point with IR = 0, as IR is a
function of Id.
 Now increase slightly the current, and press OFF. Press
now ON+TIME: the delay is the relay trip time. Also this
result can be saved. Reduce ID (or IA – IB) to a value less
than the threshold.
This procedure serves also to verify that all connections are
correct.
nd
2 test
The trip time is independent upon test parameters; so, it will
be measured in a first test, as follows.
 Slightly increase I1, press ON and increase the other
current acting on the knob (20) until the relay trips:
another point is found and can be saved as the 2
the curve:
Rev. 1.34

I I
 
A B
I
R
2
 
I I I
D A
Page 120 of 145

0 I
I

2
2
2 2

(D1000); or,
I
B 2
nd
point of