Power Line Tripping

No. Only an earth fault will trip an earth fault device.

Yes! If the unbalance current is more than the setting made in the earth fault relay.

Recently I read in an article which explains as below;

"A common misconception is that zero-sequence current only exists under fault conditions.

However, zero-sequence current can and does exist under nonfault, normal load conditions.

Unbalanced system conditions, such as those caused by nontransposed transmission lines or

unbalanced loading, can cause zero-sequence current to flow. Ground fault protection elements should never be set more sensitive than the normal system unbalance. This setting limitation means that load or system induced zero-sequence current can severely impact the sensitivity of a zero-sequence overcurrent element".

Do you agree on the above statement?.

Yes! I very much agree with the statement.

Consider following scenario in a 11kv feeder equipped with normal over current and earth fault protection relays.

The feeder tripped on overcurrent due to a short circuit and one phase jumper opened.But after test charge the line hold?

This is a major unbalance in the feeder?Can you please explain your view in this case?

Information insufficient to opine.