Applying array formula for rows with existing data

Question

I have trouble creating automation using Google Sheets. I use array formula for converting duration format from one column, to make it understandeable for Google Data Studio, however, my autiomation, when there's no existing project, needs to append a new row. But if there's an array formula applied to a column, it has created 0 values for 1000 rows, and my new row gets appended as 1001. How to fix that?

Maybe I could somehow limit the array formula to work only if there's data in the row?

I tried to find other variant of array formula from here, but none of these worked, https://support.google.com/docs/table/25273?hl=en

I could use some help. Thanks before.

Here's my spreadsheet, that I'm working on https://docs.google.com/spreadsheets/d/1zWxvwNhCExy7_9tvgJ0lo4nBmYac51NMqaqzh8kR4H4/edit?usp=sharing

Array formula applied to last column creates rows for non-existend data

Answer 1

use:

=ARRAYFORMULA(IF(E2:E="";;SECOND(E2:E)+MINUTE(E2:E)*60+HOUR(E2:E)*3600))