Sweden's power transmission system operator Svenska Kraftnat said in a message to the Nord Pool power exchange that a cable error had been detected, with the replacement of the damaged parts expected to last until 11:59 p.m. on Friday.
The power link disconnected at about 10 p.m. on Tuesday.
NordBalt last went offline due to automatic protection on June 30. It disconnected 12 times due to various malfunction since the start of 2016.
The 700-megawatt link launched regular operations in mid-July after operating in testing mode from the beginning of this year.
