Basler Electric BE1-BPR - Manual (Page 85)

9272000990 Rev J BE1-BPR Functional Description 4-33
Figure 4-8. Tc and Ti Timing Diagram
An effective Tc setting can only be made if you know when the main contacts and the 52 contacts change
state in the breaker opening cycle. Figure 4=9 shows some 52 contact designations and timing
references that may be found in some manufacturers’ literature. Typically, large variations can be found in
52a/b designs. To obtain the highest arcing time accuracy, the time relationship between the breaker
main contacts opening and the 52 contact changes of state should be measured using a travel analyzer.
Figure 4-9. 52 Contact Designation