ABB REB500 - Page 34

Section 3 1MRK 505 350-UEN
System Settings
26 Technical Manual
Distributed busbar protection REB500
Figure 4 Settings / Current transformer - Details
In the “Details” view the label in the “Markings” field can be edited. The ratios in
the “Transformer ratio” fields are entered in terms of the primary and secondary
rated currents. The secondary setting is only for information. The selection of 1 A
or 5 A as the secondary rating is achieved by appropriately connecting the CT
inputs on the REB500 bay unit.
Table 25 Parameter ranges of current transformers
Min. Max. Step
Primary [A]
I1, I2, I3, I4
50
10000
1
Secondary [A]
I1, I2, I3, I4
1
5
N/A
The direction of the bay unit currents can be reversed by enabling the checkbox
“Inverted”. REB500 internally the “Inverted” setting has the effect of a scaling
factor of -1. Normally, the setting of the “Inverted” checkbox remains unchanged
(default setting = “not inverted”).
Should it be necessary to reverse the current direction permanently,
it is recommended to achieve this via the current input wiring of the
bay unit and not by the “Inverted”-setting.