While LE can cause systems to reboot, it is important to understand the difference between tripping the external power circuit and rebooting a machine… Tripping the power circuit is unlikely unless there is a problem with the circuit or the power supply in your PC (i.e. its shorted or damaged)… LE causing your machine to reboot is different.
I am going to assume that you mean that its rebooting your machine?
Please can you post your system information, game logs and in-game settings. It is VERY difficult to help without knowing what the game is doing, what your settings are and what your system is doing.
In the meanwhile… there are some things that you need to confirm:
Verify the game files through Steam… Incomplete installations or corrupted files cause most of the crashes in LE.
Make sure you are not running any other applications while you play LE… do not use overlays (steam/nvidia etc) or any other apps - temporarily disable/or dont start them.,
It is very important that you make sure that you have enabled framerate limiting (not vsync) on your in-game settings… If you do not do this, LE will push your GPU to 100% usage and after a while, this CAN make your game crash and in some cases reboot your machine.
If you are not already doing this… Set your in-game settings to 1080p, 60frame rate limit, ALL in-game settings to very low or disabled… This is the most stable graphics configuration in the game right now and it usually helps with crashes that happen when loading new areas/maps while playing…
Please update the post with your info so that I can attempt to help further…