You say it requires a power socket. If that is the case then you had better make the power socket the reference frame otherwise it will unplug itself as soon as it starts up.

If you can tether it to the wall socket then be careful going backwards in time because it will meet itself. This will cause it to explode itself. If you are going forward in time make sure you are paying the electricity bill by direct debit and there's plenty in the bank. You don't want to get cut off.

You say it requires a power socket. If that is the case then you had better make the power socket the reference frame otherwise it will unplug itself as soon as it starts up.

This may provide your solution. Reinforce the power socket and the lead and by that means tether the machine to the wall. That way it can travel in time but it will be prevented from travelling in space.

Keeping the tether from breaking will be the tricky part. The wall end of the lead will be travelling forward in time at a standard speed of 1. The other end will be time-travelling faster or even in a negative direction. There will be a whole new theory of physics needed to work out how the speed of time travel varies along its length.

If you can tether the machine to the wall socket then be careful going backwards in time because it will meet itself. If it stops, this will cause it to explode itself. If you are going forward in time make sure you are paying the electricity bill by direct debit and there's plenty in the bank. You don't want to get cut off.