Haier 2U50S2SM1FA-3 Installation Manual page 18

Install a explosion-proof breaker for current leakage at the
power source to avoid the risk of the electric shock.
Without a breaker for current leakage will cause risks
of electric shock, fire or explosion.
Do not use large-capacity fuses,steel wire,or copper wire.
Damaging the unit ,fire,smoke or explosion will be
caused otherwise.