How a Trash Compactor Works
A trash compactor is a relatively simple appliance with only a few components. Those components include a motor, drive screws, compression ram, limit switches, door switch, exterior controls and in some units an odor control system.
The trash compactor's drawer rides on rails that allow it to slide open and closed. When the drawer is closed, the door switch enables the device to operate. When the start button is pressed, the motor is engaged and it turns a belt or chain which is connected to two drive screws. The drive screws are located on either side of the drawer. They are large diameter screws roughly the height of the trash container.
A large rectangular block, called the "ram", fits inside the trash container and presses down to compress the trash. The ram has a nut on either side, which is threaded on the drive screws. When the screws turn, the ram travels up or down.
As the ram presses down on the trash it will stall out and change direction. If the ram reaches the bottom limit switch before it stalls out, it will change direction and return to the resting position at the top. When the ram reaches the top, it triggers the top limit switch and shuts off.
Some trash compactors have an odor control system that uses a scent to mask odors or a charcoal filter to remove odors.