Domino's Pizza: Middleby Marshall PS555G Double Deck Conveyor Pizza Oven Quarterly Maintenance Form

Pre-cleaning/service steps

• Switch off the oven and allow it to cool. Do NOT service the oven while it is warm

• Turn off the electric supply circuit breaker(s) and disconnect the electric supply to the oven

• If it is necessary to move a gas oven for cleaning or servicing, disconnect the gas supply before moving the oven

Quarterly Maintenance Procedure

• Check that the oven is cool and the power is disconnected

• Vacuum both of the blower motors and their surrounding compartments, using a shop vacuum

• Tighten all electrical control terminal screws

Split Belt Disassembly and Cleaning

• Remove the motor shroud, conveyor extensions and conveyor

• Remove the master links from each conveyor belt

• Roll the belts up along the length of the conveyor to remove them from the fram

• Remove the two conveyor adjustment screws from the idler end of the conveyor frame

• Remove the idler shaft assembly from the conveyor

• Pull apart the two sections of the idler shaft

• Clean shafts thoroughly using a rag

• Lubricate both the extended shaft and the interior of the hollow shaft using an FDA-approved light food-grade lubricant

• DO NOT lubricate the shafts using WD40 or a similar product. This can cause the shafts to wear rapidly

• Before reassembling the shafts into the conveyor frame, check that they are oriented properly. Remember that unequal-width split belt ovens should ALWAYS have the narrower belt at the front of the oven

• Reassemble the idler shaft into the conveyor. Make sure that the bronze washer is in place between the two sections of the shaft

• Replace the conveyor adjustment screws. To allow the conveyor belt to be reinstalled later, do not tighten the screws at this time

• Loosen the set screw on both of the conveyor drive sprockets

• Disassemble and lubricate the two sections of the drive shaft

• Before reassembling the shafts into the conveyor frame, check that they are properly oriented.

• Reassemble the drive shaft into the conveyor. Check that the nylon spacer is in place. Also, check that the bronze washer is in place between the two sections of the shaft

• Replace the drive sprockets

• Reassemble the belts and master links onto the conveyor ,and replace the conveyor in the oven

• Reassemble the motor shroud and conveyor extensions onto the oven

Blower Beltts

• To gain access to each blower belt compartment remove the four screws shown in figure 4-8. Then, lift the read shroud off its hangers

• If access to the blower motors is required, remove the three mounting screws (two on the front of each shroud, one on the rear). Then lift the end shroud straight up and off its hangers. The end shroud can only be removed AFTER the rear shrouds have been removed.

• Check each blower belt for at least 1'' (25mm) deflection at the center, and for cracking or excessive wear. Over tightening the belt will cause premature bearing failure and possible vibrations

• If necessary, adjust the tension of the belt by loosening the four motor mounting bolts. Reposition the motor as necessary until the correct deflection is reached, then tighten the motor mounting bolts.

Lubricating the Blower Fan Bearings

• Use a grease gun to lubricate the main blower fan shaft bearings, as shown in figure 4-10

• Use a high-quality NLGI #2, lithium soap grease with petroleum oil, such as Middleby P/N 17110-0015

• Add the grease slowly until a small bead of grease is present at the seals

• Avoid over greasing as excessive greasing may cause harm to the bearing

• Manually Turn the blower shaft by pulling on the belt to purge the grease

• Wipe off any excess grease on and around the bearings

• Replace the shrouds onto the oven