Is there a limit to work such that if a person exceeds in their performance, the work ceases to be an obligation, and what is the ruling if they exceed?

The questioner did not clarify his question sufficiently, but an increase in a specific act of worship defined by a certain number or manner is not obligatory. It may even be unlawful, invalidate the act, or be disliked (makruh). Scholars have stated the dislike of exceeding the specified number in the ablution (wudu') washes, the prescribed glorifications (tasbihat) after prayer, and the amount of zakat al-fitr. The increase may invalidate the act, such as intentionally adding an extra prostration or a full bowing (rak'ah), or it may be an innovation (bid'ah), such as intentionally adding an extra circuit (shawt) in the circumambulation (tawaf) or the ritual walk (sa'i).