Middleby Marshall PS640 Adjusting the Minimum Pressure Setting, Checkout, Maintenance

Figure 2-20. Burner Assembly

Gas

Valve

Main•

Pressure•Main•

TapOrifices

Gas Burner

Assembly

Figure 2-21. Gas Valve

Adjustment Screw (5 mm)	Adjustment Screw
for minimum pressure	(8 mm) for
setting	maximum
	pressure
	setting

F.Adjusting the Minimum Pressure Setting

1.Disconnect pressure feedback connection (if appcable).

2.Connect a suitable pressure gauge to pipe line or to outlet pressure tap of gas control concerned, to measure burner pressure (measuring point must be as near to burner as possible).

3.Disconnect electrical connection of the Moduplus®.

4.Energize operator, set control in operation and wait until an outlet pressure is recorded on pressure gauge.

5.If minimum rate pressure needs adjustment, use an 8 mm wrench to turn adjustment screw for minimum pressure setting (clockwise to increase or counter-clockwise to decrease pressure), until the desired minimum outlet pressure is obtained.

6.Check if main burner lights easily and reliable at minimum pressure.

7.Reconnect pressure feedback connection (if appcable).

8.Close pressure tap screw.

G. Checkout

After any adjustment, set appliance in operation and observe through a component cycle to ensure that burner system components function correctly.

NOTE: The installer MUST verify oven operation prior to putting oven into service.

H.Maintenance

It is recommended to check yearly the minimum and the maximum setting and readjust them if necessary.

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