Warner temperature controllers use a 'universal' power entry module which allows for manual selection of the input line voltage. (The adjustment location can be found next to where the power plug connects on the rear panel.)

In addition to switching the voltage to the desired value, the correct fuse must also be selected.  Warner temperature controllers are shipped with both 120V and 240V fuses.

Should a fuse need be replaced, the correct values are shown below.

120 V	0.5 amp, slow-blow type
240 V	0.25 amp, slow-blow type