Others - Ramping
8 - 27
Testing PickUp/DropOff Value of an Overcurrent
Relay
To determine the pick up and the drop off value of a relay, a series of three
ramps is defined. The first ramp determines the pick up value, the second one
represents a 1s pause time, and the third ramp determines the drop off value.
Figure 19:
Setup for testing the
pick up and drop off
values of an
Overcurrent relay
The CPC 100 AC OUTPUT feeds the ramped current signal into a CT, which is
connected to an overcurrent relay. The overcurrent relay’s trip contact is fed into
CPC 100 binary input BinIn, and acts there as a trigger signal (as described on
page 21 of this chapter).