ABB REL 551-C1 2.3 Series Installation And Commissioning Manual page 84

78
Definite and inverse time-delayed
residual overcurrent protection (TEF)
15. Connect the rated DC voltage to the TEF--BLKTR configured
binary input and switch on the fault current.
No TEF--TRIP nor TEF--TRSOTF should appear. But the output
TEF--START shall be activated.
16. Continue to test another function or complete the test by set-
ting the test mode to off.
Chapter 11
Verifying settings by secondary
injection