Middleby Marshall PS220, PS570, PS360, PS200, PS555, PS224 PS310 129, IX. Pilot Pressure Adjustment

SECTION 3 - SERVICING COMPONENTS

Appendix - Instructions for All Gas Conversion Kits

for Ovens with Wayne Burner, Propane to Natural Gas, 8/00

VII. GAS LEAK TEST VIII. INLET PRESSURE CHECK

1.Restore the electrical and gas utility connections to the oven.

2.Paint all gas pipe connections from the union to the venturi mounting plate, as well as the pilot tubing, bypass tubing, and pressure tap plug, with a rich solution of soap and water (2/3 soap, 1/3 water is recommended). Any visible bubbles indicate a gas leak.

3.If a gas leak is detected, tighten the affected joints and connections. If tightening the connection(s) fails to stop the leak:

•Turn off the electric power supply to the oven.

•Turn off the gas supply at the service valve behind the oven.

•Replace the affected component(s).

•Repeat the gas leak test.

WARNING - FIRE/EXPLOSION HAZARD HIDDEN GAS LEAKS CAN CAUSE A FLASHBACK IN THE MACHINERY COMPARTMENT. THIS CAN CAUSE SEVERE INJURY OR DEATH. STAND WELL CLEAR WHEN SWITCHING ON THE HEATING CIRCUIT.

4.If no leaks are detected by the test, depress the safety switch(es) and switch on the oven. Then, switch on the heating circuit to ignite the burner.

5.With the burner in operation, paint all gas pipe joints with the solution of soap and water.

6.If any further gas leaks are detected, shut down the oven. Reseal and tighten the affected joints and connections. If tightening the connection(s) fails to stop the leak:

•Turn off the electric power supply to the oven.

•Turn off the gas supply at the service valve behind the oven.

•Replace the affected component(s).

•Repeat the gas leak test.

1.Using a manometer, check the inlet pressure at the inlet pressure tap. See Figure 6. An inlet pressure of 6-12” W.C. (14.9-29.9mbar) is recommended for natural gas operation.

2.If the inlet pressure is:

•HIGHER THAN 14” W.C. (34.9mbar) - This pressure may damage the combination gas control valve (safety regulator). The gas supply pressure should be decreased.

•LOWER THAN 6” W.C. (14.9mbar) - It may be necessary to increase the supplied gas pressure.

CAUTION

IF IT IS NECESSARY TO ADJUST THE GAS LINE PRESSURE, HAVE THE CUSTOMER CONTACT THE GAS UTILITY SUPPLIER.

IX. PILOT PRESSURE ADJUSTMENT

1.Unscrew the cap plug from the pilot pressure tap (pilot tee), and attach a manometer to the tap. See Figure 6.

2.Remove the pilot adjustment cap screw from the combination gas control valve.

3.Turn the oven on, and allow it to heat to temperature. Make a note of the customer’s set point temperature.

4.After the oven has heated, adjust the set point of the oven far lower than its current (operating) temperature. This ensures that the pilot flame will be at its lowest level for some time.

Continued...

ENGLISH

Figure 6

Adjust manifold pressure here (under cap screw)

Measure inlet	Measure
	manifold
pressure here
	pressure here

Measure pilot pressure here

(under cap plug)Adjust pilot pressure here

(under cap screw)

5

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