ENGLISH

SECTION4-MAINTENANCE

E.Blower Belts

1.To gain access to each blower belt compartment, remove the four screws shown in Figure 4-8. Then, lift the rear 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 shrouds can only be removed AFTER the rear shrouds have been removed.

2.Check each blower belt for at least 1" (25mm) deflec- tion at the center, and for cracking or excessive wear. See Figure 4-9. Overtightening the belt will cause premature bearing failure and possible vibrations.

3.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.

F.Lubricating the Blower Fan Bearings

1.Use a grease gun to lubricate the main blower fan shaft bearings, as shown in Figure 4-10.

When lubricating the bearings:

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 OVERGREASING. Excessive greasing may cause harm to the bearing.

2.Manually turn the blower shaft by pulling on the belt to purge the grease.

3.Wipe off any excess grease on and around the bear- ings.

4.Replace the shrouds onto the oven.

NOTE

The oven will not operate unless ALL of the motor and rear shrouds are in place.

IV. MAINTENANCE - EVERY 6 MONTHS

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

B.Check for excessive wear on the conveyor drive motor brushes. The brushes should be replaced if they have worn to less than 1/4" (6.4mm) in length. Be sure to replace the brushes in exactly the same position.

C.For gas ovens, clean and inspect the burner nozzle and electrode assembly.

D.Check (and clean, if necessary) the oven venting system.

E.Check the conveyor drive shaft bushings and spacers. Replace the components if they are worn.

Figure 4-8 - Rear Shrouds and Guard Plates

End shroud screws

(3 per shroud - 1

rear, 2 front)

Rear shroud screws

Rear shroud -

End shroud -

remove SECOND (if

(4 per shroud for gas

remove FIRST.

necessary).

ovens, 5 per shroud

Access to bearing

Access to blower

for electric ovens)

and fan belt

motor

 

Figure 4-9 - Fan Belt Tension

At least 1" (25mm)

deflection

Fan not shown -

see above

To adjust belt

tension, loosen 4

bolts and

reposition motor

Figure 4-10 - Lubricating the Bearings

Grease fittings

(1 per bearing, 4

total)

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Middleby Marshall PS500 IV. Maintenance Every 6 Months, Blower Belts, Lubricating the Blower Fan Bearings