HPM 24 hour timer has segments located around dial.http://waterheatertimer.org/Woods-timers-and-manuals.html#HPM-dialhttp://waterheatertimer.org/images/hpm-24hr-timer-500.jpg
Segments appear to move up or down.
Other similar timers: Segments down = Load ON; Segments up = Load OFF
Press several segments down.
Plug timer into wall.
Plug 240Volt load into timer.
Manually rotate timer dial clockwise to see if segments down turn load on or off.
There is also a 2-position slide-switch located on top of timer.
Move slide switch to each position to see which is need for timer to turn load on-off.
After positions are defined, push segments down or leave segments up for times you want load to turn on.
Rotate dial clockwise until current time lines up with arrowhead located on inner dial.
Timer dial rotates as time passes, and segments move a plastic lever that turns load on and off
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