Middleby Marshall PS640 installation manual II. Maintenance Monthly, Top Row Bottom Row

II. MAINTENANCE – MONTHLY

NOTE: When removing the conveyor, refer to Figure 2-12 (in Section 2, Installation).

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

B.Remove the crumb trays from the oven.

C.Lift the drive end of the conveyor slightly, and push it forward into the oven. This removes the tension from the drive chain. Then, remove the drive chain from the con- veyor sprocket.

D.Slide the conveyor out of the oven, folding it as it is removed.

E.Remove the end plugs from the oven. The end plugs are shown in Figure 1-1 (in Section 1, Description).

F.Slide the air fingers and blank plates out of the oven, as shown in Figure 4-2. AS EACH FINGER OR PLATE IS REMOVED, WRITE A “LOCATION CODE” ON IT WITH A MARKER to make sure that it can be reinstalled correctly.

Example of markings:

(Top Row)	T1	T2	T3	T4	T5	T6
(Bottom Row)	B1	B2	B3	B4	B5	B6

G.Disassemble the air fingers as shown in Figure 4-3. AS EACH FINGERISDISASSEMBLED,WRITETHE“LOCATIONCODE” FOR THE FINGER ON ALL THREE OF ITS PIECES. This will help you in correctly reassembling the air fingers.

CAUTION: Incorrect reassembly of the air fingers will change

the baking properties of the oven.

H.Clean the air finger components and the interior of the baking chamber using a vacuum cleaner and a damp cloth. Refer to the boxed warnings at the beginning of this Section for cleaning precautions.

I.Reassemble the air fingers. Then, replace them in the oven, using the “location guide” as a guide.

J.Replace the end plugs on the oven.

K.Reassemble the conveyor into the oven. If the drive sprocket was removed when installing the conveyor, replace it at this time.

L.Reattach the drive chain.

M.Check the tension of the conveyor belt as shown in Figure

2-14 (in Section 2, Installation). The belt should lift between 3 - 4″ (75-100mm). DO NOT OVERTIGHTEN THE CONVEYOR BELT. If necessary, the belt tension can be adjusted by turning the conveyor adjustment screws, located at the idler (right) end of the conveyor.

N.Replace the crumb trays.

Figure 4-2. Removing Air Fingers and Plates

Figure 4-3. Disassembling the Air Fingers

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