III. Maintenance Every 3 Months | Middleby Marshall PS640 guide

III. MAINTENANCE – EVERY 3 MONTHS

A.Check that the oven is cool and the power is discon- nected, as described in the warning at the beginning of this Section.

B.Vacuum both of the blower mounts, and their surrounding compartments, using a shop vacuum.

C.Tighten all electrical terminal screws.

D.Split Belt Disassembly and Cleaning

1.Refer to Part D, Conveyor Installation, in the Installa- tion section of this Manual. Then, remove the following components from the oven:

•Conveyor end stop

•Crumb trays

•Chain cover

•Drive chains

•End plugs

•Conveyor assembly

2.Remove the master links from each conveyor belt. Then, roll the belts up along the length of the conveyor to remove them from the frame.

3.Remove the two conveyor adjustment screws from the idler end of the conveyor frame, as shown in Figure 4-4.

4.Remove the idler shaft assembly from the conveyor.

5.Pull apart the two sections of the idler shaft.

6.Clean the shafts thoroughly using a rag. Then, lubri-cate both the extended shaft and the interior of the hollow shaft using a light food-grade lubricant. DO NOT lubricate the shafts using WD40 or a similar product. This can cause the shafts to wear rapidly.

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

Figure 4-4. Disassembling the idler shaft

8.Reassemble the idler shaft into the conveyor. Make sure that the bronze washer is in place between the two sections of the shaft. See Figure 4-4.

9.Replace the conveyor adjustment screws as shown in Figure 4-4. To allow the conveyor belt to be reinstalled later, do not tighten the screws at this time.

10.Loosen the set screw on both of the conveyor drive sprockets. Then, remove the sprockets from the shaft.

11.Check the conveyor configuration as follows:

High-speed conveyors are equipped with large flange bearings at both ends of the shaft, as shown in Figure 4-5. For these conveyors, remove the two screws that hold each bearing to the conveyor frame. With the screws removed, lift the end of the shaft at the front of the oven, and pull the entire assembly free of the conveyor frame.

Standard conveyors are equipped with bronze bush- ings mounted on spacers at both ends of the shaft, as shown in Figure 4-5. For these convey-ors, remove the two screws that hold the bracket to the conveyor frame. With the screws removed, lift the end of the shaft at the front of the oven, and pull the entire assembly free of the conveyor frame. The brackets will be removed along with the drive shaft assembly.

12.Disassemble and lubricate the two sections of the drive shaft as described for the idler shaft, above.

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

14.Reassemble the drive shaft into the conveyor. Make sure that the bronze washer is in place between the two sections of the shaft. See Figure 4-4.

15.Replace the drive sprockets. Reassemble the belts and master links onto the conveyor.

16.Reinstall the end plugs and conveyor onto the oven.

17.Reattach the drive chains. Replace the chain cover.

18.Check the tension of the conveyor belt as shown in

Figure 2-14 (in Section 2, Installation). The belt should lift about 1″ (25mm). If necessary, adjust the belt tension by turning the conveyor adjustment screws.

19.Replace all components onto the oven.

Middleby Marshall PS640 III. Maintenance Every 3 Months, Split Belt Disassembly and Cleaning