Seems like you're not seeing any deprecation warnings, in the newer versions of pandas convert_objects/convert_numeric is deprecated, I presume due to memory issues.
Are you not seeing a deprecation warning?

If so:
pip freeze > freeze.txt
pip install --upgrade pandas
and re-run your python file, you'll then see the deprecation warnings.

Instead of convert_objects(convert_numeric=True) try using pd.to_numeric(), you only need timeSeconds converted to numerical type, converting one field instead of all is one memory optimization step I see clearly visible.

To see other memory issues, try using a memory profiler to find the memory bottlenecks. The profiler will tell you which line numbers are hogging up resources.

memory_profiler and line_profiler are two profilers that I use when bottleneck resolution is required.

pip install memory_profiler
pip install line_profiler