Repairs for a Trash Compactor | How to fix jammed trash compactor

Devotees of the space and time saving trash compactor, accustomed to fewer trips outside to the garbage can, may feel a real pinch if the masher runs amok. Luckily, repairs usually are simple.

A malfunctioning compactor either will refuse to run at all, will stop in midcycle or will run continuously. In each case, the problem probably is electrical. The six switches (opposite, bottom left) that control the up and down motion of the metal ram are quite vulnerable to the movement of this ram, which exerts up to 3,000 pounds of pressure to crush into a hatbox sized space the trash that would normally fill two 20-gallon cans.

If the compactor fails to start, make sure the problem is not caused by a simple oversight an unplugged cord, a tripped circuit or blown fuse, or your own failure to unlock the safety switch or to close the drawer completely before pressing the start button. If everything is in order and the compactor still will not run, the problem is within the machine and you must expose its innards.

Most compactors are serviced from the bottom or the back; after unplugging the unit, simply unscrew and remove the appropriate panel. If necessary, you can also remove the side and top panels the same way. To remove the drawer, pull it all the way out and lift it off its tracks.

Once the circuitry is exposed, perform a continuity test at each switch. You may find that a nonfunctioning switch arm is not making proper contact and needs only to be bent back into position.

If the continuity tests reveal no malfunctions in the electrical system, the problem is a mechanical one. There are several parts that may break down with normal day to day use, and they usually have telltale symptoms. If there is excessive machine noise, or if the motor runs but the ram does not move, there are damaged gears in the motor or a loose or broken drive chain. You can tighten the chain by repositioning the motor as shown at top, opposite; if the chain is broken, it can be replaced. Damaged gears are trickier to remove and replace, and may warrant a call to a professional.

Occasionally, the ram will complete only half of its cycle, refusing to budge from the bottom of the compactor because the power nuts are worn or stripped. The power nuts, which are part of the screw and nut system that pushes the ram down and pulls it back up, are mounted on top of the ram and can be replaced by the method shown at lower, opposite.

How a compactor mashes trash 

During the 30 to 60 second work cycle of the trash compactor, the metal ram located in the center of the machine travels down into the trash container and then moves back up to its starting position above the top of the container. This action is initiated by a 'A horsepower motor. The motor drives a chain around three sprockets, causing two power screws one situated at either side of the ram to spin slowly, threading their way through the two power nuts that are mounted on top of the ram.

When the machine starts, the power screws turn in one direction to draw the ram down into the trash compartment. The ram descends until it exerts a set amount of pressure generally 2,000 to 3,000 pounds either on the trash in the container or, if there is not enough trash, on four rubber bumpers at the sides of the compactor. At this point the motor pauses and then, directed by the reversing switch at the top of the unit, begins to turn in the opposite direction.The power screws turn in the opposite direction too, and the ram returns to starting position.

The electrical system of the machine. 

A standard trash compactor has six electrical switches that direct the ram through its cycle. The on/off switch, manually controlled, begins the cycle and can also be used to stop the ram's cycle at any point. The key operated safety switch beside the on/off switch locks the system so that neither a child nor an inadvertent flick of the wrist can turn the power on.

The limit switch has a levered arm that flips to the on position as the ram begins its downward path, supplying the current to run the motor When the ram returns to the top, at the end of the cycle, the arm flips to the off position and the current is shut off. The reversing switch, beside the limit switch, works in the same way, flipping on as the ram passes. This switch changes the polarity of the current reaching the motor so that when the ram ends its downward movement and the motor pauses, the motor reverses the drive chain and power screws to pull the ram upward.

The two drawer switches are safety switches. The rear switch interrupts the flow of current when the drawer is open; the front switch lets the current flow when the drawer is shut tightly.

 If you must replace the limit switch, position the new one so that its levered arm is up when the ram is at its highest point. Similarly, position a new rear drawer switch so that the drawer will slide underneath the levered arm to lift the switch into the on position.

Adjusting the drive chain. 

Unplug the compactor, lay it on its side and remove the bottom panel to expose the drive chain, the motor sprocket and the two drive sprockets. Loosen the nuts in the elongated adjustment holes on the motor mount plate and, gripping the motor pulley wheel, push or pull the entire motor assembly to adjust the tension in the chain; there should be about 1/4 inch of give when the chain is pressed from the side. Tighten the adjustment nuts on the motor mount plate and lubricate the drive chain lightly with No. 30 motor oil.

If the drive chain is broken, replace it with a new chain, available from the manufacturer. Assemble the new chain with its master link and, after loosening the motor assembly and pushing it as far toward the front of the machine as it will go, install the chain on its sprockets. Adjust the tension in the new chain as before.

On some compactors you may find a tension regulator spring attached to the old chain. Remove the spring before you remove the chain, then replace it when the new chain is installed.

Replacing a worn power nut.

The exploded view at left shows how the two halves of the power nut fit around the power screw and how the power nut housing, which is secured to the top of the ram with two nuts, encases the power nut to hold it securely in place.

To replace a stripped power nut, unplug the compactor and remove the top panel to expose the top of the ram. Tape the limit switch and reversing switch out of the way of the ram.

Then tilt the machine to one side and reach beneath it to turn the chain sprockets by hand, moving the ram up until it can be lifted off the tops of the power screws. Remove the power nut and its housing from the top of the ram; set the new nut and housing in place, aligning the stops on both sides of the nut with the stops in the housing. Hand tighten the housing nuts.

Replace the ram on the power screws, and turn the chain sprockets to lower the ram 1 inch. Tighten the housing nuts with a wrench, making sure the housing's outer edge does not protrude beyond the edge of the ram. Lubricate the power nut assembly with molybdenum and lithium grease, available at hardware stores.Then remove the tape, releasing the switches.